Orbit Data Messages (CCSDS 502.0-B-3)
Fix Rice codec, consolidate ODM/ADM, add ocaml-ccsds index
Rice (CCSDS 121.0-B):
- Fix prediction error mapper per spec (modular arithmetic with
theta-based branching, matching libaec reference implementation)
- Fix select_k to use floor instead of round
- Add bounds check on decompress sample count
- All 11 tests + 4 fuzz tests pass
ODM consolidation (CCSDS 502.0-B):
- Merge OPM into ocaml-odm alongside OEM
- Access via Odm.Oem and Odm.Opm submodules
- Backward-compatible: Odm.of_kvn_string still works for OEM
ADM (CCSDS 504.0-B):
- Create ocaml-adm from ocaml-aem
- Access via Adm.Aem submodule (APM to be added)
ocaml-ccsds index:
- Meta-package with index.mld documenting the full protocol suite
- Organized by Blue Book / Green Book / Related Standards
- Links to CCSDS PDF specs for each standard
- Lists all implemented + not-yet-implemented specs
+1402
-574
+4
-3
dune-project
+4
-3
dune-project
···
12
12
(name odm)
13
13
(synopsis "Orbit Data Messages (CCSDS 502.0-B-3)")
14
14
(description
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"Parse and manipulate Orbit Data Messages for satellite ephemeris \
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exchange. Supports CCSDS 502.0-B-3 OEM (Orbit Ephemeris Message) \
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KVN format with multi-segment and acceleration data.")
15
+
"Parse and manipulate Orbit Data Messages (CCSDS 502.0-B-3) for \
16
+
satellite ephemeris exchange. Includes OEM (Orbit Ephemeris Message) \
17
+
and OPM (Orbit Parameter Message) KVN format parsers.")
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18
(depends
19
19
(ocaml (>= 4.14))
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+
kvn
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21
ptime
21
22
fmt
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23
(alcotest :with-test)))
+1
-1
lib/dune
+1
-1
lib/dune
+10
-451
lib/odm.ml
+10
-451
lib/odm.ml
···
1
-
(** Orbit Data Messages (CCSDS 502.0-B-3). *)
2
-
3
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type vec3 = Vec3.t = { x : float; y : float; z : float }
4
-
5
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type state_vector = {
6
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epoch : string;
7
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pos : vec3;
8
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vel : vec3;
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accel : vec3 option;
10
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}
11
-
12
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type metadata = {
13
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object_name : string;
14
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object_id : string;
15
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center_name : string;
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ref_frame : string;
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time_system : string;
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start_time : string;
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stop_time : string;
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useable_start_time : string option;
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useable_stop_time : string option;
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interpolation : string option;
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interpolation_degree : int option;
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}
25
-
26
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type covariance_entry = {
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cov_epoch : string;
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cov_ref_frame : string;
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cov : float array;
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}
31
-
32
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type segment = {
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metadata : metadata;
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data : state_vector array;
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covariances : covariance_entry list;
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comments : string list;
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}
38
-
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type header = {
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ccsds_oem_vers : string;
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creation_date : string;
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originator : string;
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comments : string list;
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}
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-
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type t = { header : header; segments : segment list }
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-
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type error =
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| Missing_header
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| Missing_metadata
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| Bad_line of { line : int; content : string }
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| Parse_error of string
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-
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let pp_error ppf = function
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| Missing_header -> Fmt.pf ppf "missing OEM header"
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| Missing_metadata -> Fmt.pf ppf "missing META_START"
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| Bad_line { line; content } -> Fmt.pf ppf "bad line %d: %s" line content
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| Parse_error msg -> Fmt.pf ppf "parse error: %s" msg
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-
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(* Pretty-printers *)
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-
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let pp_vec3 ppf v = Fmt.pf ppf "(%.6f, %.6f, %.6f)" v.x v.y v.z
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-
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let pp_state_vector ppf sv =
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Fmt.pf ppf "%s pos=%a vel=%a" sv.epoch pp_vec3 sv.pos pp_vec3 sv.vel;
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match sv.accel with None -> () | Some a -> Fmt.pf ppf " accel=%a" pp_vec3 a
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-
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let pp_metadata ppf m =
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Fmt.pf ppf
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"@[<v>OBJECT_NAME = %s@,\
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OBJECT_ID = %s@,\
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CENTER_NAME = %s@,\
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REF_FRAME = %s@,\
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TIME_SYSTEM = %s@,\
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START_TIME = %s@,\
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STOP_TIME = %s@]"
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m.object_name m.object_id m.center_name m.ref_frame m.time_system
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m.start_time m.stop_time
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-
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let pp_segment ppf seg =
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Fmt.pf ppf "@[<v>META:@, %a@,DATA: %d vectors@]" pp_metadata seg.metadata
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(Array.length seg.data)
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-
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let pp_header ppf h =
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Fmt.pf ppf "CCSDS_OEM_VERS = %s@,CREATION_DATE = %s@,ORIGINATOR = %s"
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h.ccsds_oem_vers h.creation_date h.originator
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-
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let pp ppf t =
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Fmt.pf ppf "@[<v>%a@,%a@]" pp_header t.header
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Fmt.(list ~sep:(Fmt.any "@,") pp_segment)
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-
t.segments
1
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(** Orbit Data Messages (CCSDS 502.0-B-3).
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2
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(* Accessors *)
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This module groups the orbit data message types defined in CCSDS 502.0-B:
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4
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let segments t = t.segments
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let state_vectors seg = seg.data
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let epoch_range seg = (seg.metadata.start_time, seg.metadata.stop_time)
5
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- {!Oem}: Orbit Ephemeris Message
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- {!Opm}: Orbit Parameter Message
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(* Parsing helpers *)
8
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For backward compatibility, the OEM types and functions are also re-exported
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at the top level of this module (e.g., [Odm.of_kvn_string] is an alias for
10
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[Odm.Oem.of_kvn_string]). *)
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11
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let trim s = String.trim s
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let split_kv line =
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match String.index_opt line '=' with
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| None -> None
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| Some i ->
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let key = trim (String.sub line 0 i) in
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let value = trim (String.sub line (i + 1) (String.length line - i - 1)) in
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Some (key, value)
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-
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let is_data_line s =
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let s = trim s in
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String.length s > 0
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&&
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let c = s.[0] in
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(c >= '0' && c <= '9') || c = '-'
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-
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let split_spaces s =
119
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String.split_on_char ' ' s |> List.filter (fun s -> String.length s > 0)
120
-
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let parse_state_vector line_num line =
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let tokens = split_spaces (trim line) in
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match tokens with
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| epoch :: rest -> (
125
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let floats =
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List.map
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(fun s ->
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match float_of_string_opt s with Some f -> f | None -> Float.nan)
129
-
rest
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in
131
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match floats with
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| [ x; y; z; vx; vy; vz ] ->
133
-
Ok
134
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{
135
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epoch;
136
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pos = { x; y; z };
137
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vel = { x = vx; y = vy; z = vz };
138
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accel = None;
139
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}
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| [ x; y; z; vx; vy; vz; ax; ay; az ] ->
141
-
Ok
142
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{
143
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epoch;
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pos = { x; y; z };
145
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vel = { x = vx; y = vy; z = vz };
146
-
accel = Some { x = ax; y = ay; z = az };
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-
}
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| _ -> Error (Bad_line { line = line_num; content = line }))
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| [] -> Error (Bad_line { line = line_num; content = line })
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-
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let empty_metadata =
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{
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object_name = "";
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object_id = "";
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center_name = "";
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ref_frame = "";
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time_system = "";
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start_time = "";
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stop_time = "";
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useable_start_time = None;
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useable_stop_time = None;
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interpolation = None;
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interpolation_degree = None;
164
-
}
165
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let set_meta_field meta key value =
167
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match key with
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| "OBJECT_NAME" -> { meta with object_name = value }
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| "OBJECT_ID" -> { meta with object_id = value }
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| "CENTER_NAME" -> { meta with center_name = value }
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| "REF_FRAME" -> { meta with ref_frame = value }
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| "TIME_SYSTEM" -> { meta with time_system = value }
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| "START_TIME" -> { meta with start_time = value }
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| "STOP_TIME" -> { meta with stop_time = value }
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| "USEABLE_START_TIME" -> { meta with useable_start_time = Some value }
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| "USEABLE_STOP_TIME" -> { meta with useable_stop_time = Some value }
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| "INTERPOLATION" -> { meta with interpolation = Some value }
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| "INTERPOLATION_DEGREE" -> (
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match int_of_string_opt value with
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| Some d -> { meta with interpolation_degree = Some d }
181
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| None -> meta)
182
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| _ -> meta
183
-
184
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type parse_state = Header | Meta | Data | Covariance
185
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186
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type parse_ctx = {
187
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mutable state : parse_state;
188
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mutable header_vers : string;
189
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mutable header_date : string;
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mutable header_orig : string;
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mutable header_comments : string list;
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mutable cur_meta : metadata;
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mutable cur_data : state_vector list;
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mutable cur_covs : covariance_entry list;
195
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mutable cur_cov_epoch : string;
196
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mutable cur_cov_frame : string;
197
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mutable cur_cov_values : float list;
198
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mutable cur_comments : string list;
199
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mutable segments_acc : segment list;
200
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mutable has_header : bool;
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mutable has_meta : bool;
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mutable err : error option;
203
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mutable line_num : int;
204
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}
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206
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let extract_comment trimmed =
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if String.length trimmed > 8 then
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trim (String.sub trimmed 8 (String.length trimmed - 8))
209
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else ""
210
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let is_comment trimmed =
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String.length trimmed >= 7 && String.sub trimmed 0 7 = "COMMENT"
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let finish_cov_entry ctx =
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if ctx.cur_cov_epoch <> "" && ctx.cur_cov_values <> [] then begin
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let entry =
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{
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cov_epoch = ctx.cur_cov_epoch;
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cov_ref_frame = ctx.cur_cov_frame;
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cov = Array.of_list ctx.cur_cov_values;
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}
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in
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ctx.cur_covs <- entry :: ctx.cur_covs;
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ctx.cur_cov_epoch <- "";
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ctx.cur_cov_frame <- "";
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ctx.cur_cov_values <- []
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end
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229
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let finish_segment ctx =
230
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let seg =
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{
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metadata = ctx.cur_meta;
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data = Array.of_list (List.rev ctx.cur_data);
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covariances = List.rev ctx.cur_covs;
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comments = List.rev ctx.cur_comments;
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}
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in
238
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ctx.segments_acc <- seg :: ctx.segments_acc;
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ctx.cur_data <- [];
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ctx.cur_covs <- [];
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ctx.cur_comments <- []
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-
243
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let process_header ctx trimmed =
244
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if is_comment trimmed then
245
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ctx.header_comments <- extract_comment trimmed :: ctx.header_comments
246
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else if trimmed = "META_START" then begin
247
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ctx.has_meta <- true;
248
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ctx.state <- Meta;
249
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ctx.cur_meta <- empty_metadata
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end
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else
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match split_kv trimmed with
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| Some ("CCSDS_OEM_VERS", v) ->
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ctx.has_header <- true;
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ctx.header_vers <- v
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| Some ("CREATION_DATE", v) -> ctx.header_date <- v
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| Some ("ORIGINATOR", v) -> ctx.header_orig <- v
258
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| _ -> ()
259
-
260
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let process_meta ctx trimmed =
261
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if trimmed = "META_STOP" then ctx.state <- Data
262
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else
263
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match split_kv trimmed with
264
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| Some (k, v) -> ctx.cur_meta <- set_meta_field ctx.cur_meta k v
265
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| None -> ()
266
-
267
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let process_data ctx trimmed =
268
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if is_comment trimmed then
269
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ctx.cur_comments <- extract_comment trimmed :: ctx.cur_comments
270
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else if trimmed = "META_START" then begin
271
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finish_segment ctx;
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ctx.state <- Meta;
273
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ctx.cur_meta <- empty_metadata
274
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end
275
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else if trimmed = "COVARIANCE_START" then ctx.state <- Covariance
276
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else if is_data_line trimmed then
277
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match parse_state_vector ctx.line_num trimmed with
278
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| Ok sv -> ctx.cur_data <- sv :: ctx.cur_data
279
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| Error e -> ctx.err <- Some e
280
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else ()
281
-
282
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let process_covariance ctx trimmed =
283
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if trimmed = "COVARIANCE_STOP" then begin
284
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finish_cov_entry ctx;
285
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ctx.state <- Data
286
-
end
287
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else if is_comment trimmed then ()
288
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else
289
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match split_kv trimmed with
290
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| Some ("EPOCH", v) ->
291
-
finish_cov_entry ctx;
292
-
ctx.cur_cov_epoch <- v
293
-
| Some ("COV_REF_FRAME", v) -> ctx.cur_cov_frame <- v
294
-
| _ ->
295
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(* Data line: parse floats (lower triangle row) *)
296
-
let floats =
297
-
split_spaces trimmed
298
-
|> List.filter_map (fun s -> float_of_string_opt s)
299
-
in
300
-
ctx.cur_cov_values <- ctx.cur_cov_values @ floats
301
-
302
-
let parse_lines lines =
303
-
let ctx =
304
-
{
305
-
state = Header;
306
-
header_vers = "";
307
-
header_date = "";
308
-
header_orig = "";
309
-
header_comments = [];
310
-
cur_meta = empty_metadata;
311
-
cur_data = [];
312
-
cur_covs = [];
313
-
cur_cov_epoch = "";
314
-
cur_cov_frame = "";
315
-
cur_cov_values = [];
316
-
cur_comments = [];
317
-
segments_acc = [];
318
-
has_header = false;
319
-
has_meta = false;
320
-
err = None;
321
-
line_num = 0;
322
-
}
323
-
in
324
-
List.iter
325
-
(fun line ->
326
-
ctx.line_num <- ctx.line_num + 1;
327
-
if ctx.err <> None then ()
328
-
else
329
-
let trimmed = trim line in
330
-
if String.length trimmed = 0 then ()
331
-
else
332
-
match ctx.state with
333
-
| Header -> process_header ctx trimmed
334
-
| Meta -> process_meta ctx trimmed
335
-
| Data -> process_data ctx trimmed
336
-
| Covariance -> process_covariance ctx trimmed)
337
-
lines;
338
-
match ctx.err with
339
-
| Some e -> Error e
340
-
| None ->
341
-
if not ctx.has_header then Error Missing_header
342
-
else if not ctx.has_meta then Error Missing_metadata
343
-
else begin
344
-
(match ctx.state with
345
-
| Data | Covariance -> finish_segment ctx
346
-
| _ -> ());
347
-
Ok
348
-
{
349
-
header =
350
-
{
351
-
ccsds_oem_vers = ctx.header_vers;
352
-
creation_date = ctx.header_date;
353
-
originator = ctx.header_orig;
354
-
comments = List.rev ctx.header_comments;
355
-
};
356
-
segments = List.rev ctx.segments_acc;
357
-
}
358
-
end
359
-
360
-
let of_kvn_string s =
361
-
let lines = String.split_on_char '\n' s in
362
-
parse_lines lines
363
-
364
-
let of_kvn_channel ic =
365
-
let lines = ref [] in
366
-
(try
367
-
while true do
368
-
lines := input_line ic :: !lines
369
-
done
370
-
with End_of_file -> ());
371
-
parse_lines (List.rev !lines)
372
-
373
-
let of_kvn_file path =
374
-
let ic = open_in path in
375
-
let result = of_kvn_channel ic in
376
-
close_in ic;
377
-
result
378
-
379
-
(* Interpolation *)
380
-
381
-
let epoch_to_unix epoch =
382
-
(* Parse ISO 8601 timestamp to unix timestamp *)
383
-
match Ptime.of_rfc3339 (epoch ^ "Z") with
384
-
| Ok (t, _, _) -> Some (Ptime.to_float_s t)
385
-
| Error _ -> (
386
-
(* Try without the Z suffix in case it already has timezone *)
387
-
match Ptime.of_rfc3339 epoch with
388
-
| Ok (t, _, _) -> Some (Ptime.to_float_s t)
389
-
| Error _ -> None)
390
-
391
-
(** Lagrange polynomial interpolation of vec3 over a window of data points.
392
-
[times] has length [k], [positions] has length [k], [t] is the query time.
393
-
*)
394
-
let lagrange_vec3 times positions t =
395
-
let k = Array.length times in
396
-
let x = ref 0.0 and y = ref 0.0 and z = ref 0.0 in
397
-
for j = 0 to k - 1 do
398
-
let basis = ref 1.0 in
399
-
for m = 0 to k - 1 do
400
-
if m <> j then
401
-
basis := !basis *. (t -. times.(m)) /. (times.(j) -. times.(m))
402
-
done;
403
-
x := !x +. (!basis *. positions.(j).x);
404
-
y := !y +. (!basis *. positions.(j).y);
405
-
z := !z +. (!basis *. positions.(j).z)
406
-
done;
407
-
{ x = !x; y = !y; z = !z }
408
-
409
-
let interpolate seg unix_t =
410
-
let data = seg.data in
411
-
let n = Array.length data in
412
-
let degree =
413
-
match seg.metadata.interpolation_degree with Some d -> d | None -> 7
414
-
in
415
-
if n < 2 then None
416
-
else
417
-
(* Convert all epochs to unix timestamps *)
418
-
let times =
419
-
Array.map
420
-
(fun sv ->
421
-
match epoch_to_unix sv.epoch with Some t -> t | None -> Float.nan)
422
-
data
423
-
in
424
-
if Array.exists Float.is_nan times then None
425
-
else
426
-
let t0 = times.(0) and tn = times.(n - 1) in
427
-
if unix_t < t0 || unix_t > tn then None
428
-
else
429
-
(* Binary search for bracketing interval *)
430
-
let lo = ref 0 and hi = ref (n - 2) in
431
-
while !hi - !lo > 1 do
432
-
let mid = (!lo + !hi) / 2 in
433
-
if times.(mid) <= unix_t then lo := mid else hi := mid
434
-
done;
435
-
let i =
436
-
if times.(!lo) <= unix_t && unix_t <= times.(!lo + 1) then !lo
437
-
else !lo + 1
438
-
in
439
-
(* Select centered window of degree+1 points around interval [i, i+1] *)
440
-
let needed = min (degree + 1) n in
441
-
let half = (needed - 2) / 2 in
442
-
let start = max 0 (min (i - half) (n - needed)) in
443
-
let win_t = Array.sub times start needed in
444
-
let win_p = Array.init needed (fun j -> data.(start + j).pos) in
445
-
Some (lagrange_vec3 win_t win_p unix_t)
446
-
447
-
let position_at oem unix_t =
448
-
let rec try_segments = function
449
-
| [] -> None
450
-
| seg :: rest -> (
451
-
match interpolate seg unix_t with
452
-
| Some _ as result -> result
453
-
| None -> try_segments rest)
454
-
in
455
-
try_segments oem.segments
12
+
module Oem = Oem
13
+
module Opm = Opm
14
+
include Oem
+17
-117
lib/odm.mli
+17
-117
lib/odm.mli
···
1
1
(** Orbit Data Messages (CCSDS 502.0-B-3).
2
2
3
-
Parse and manipulate Orbit Ephemeris Messages (OEM) in KVN format. Supports
4
-
multi-segment files, optional acceleration data, and linear interpolation.
5
-
6
-
{b References}:
7
-
- CCSDS 502.0-B-3, Orbit Data Messages *)
8
-
9
-
(** {1 Types} *)
10
-
11
-
type vec3 = Vec3.t = { x : float; y : float; z : float }
12
-
(** 3D vector (km, km/s, or km/s²). *)
13
-
14
-
type state_vector = {
15
-
epoch : string;
16
-
pos : vec3;
17
-
vel : vec3;
18
-
accel : vec3 option;
19
-
}
20
-
(** Cartesian state vector with epoch. Position in km, velocity in km/s,
21
-
acceleration in km/s² (optional). *)
22
-
23
-
type metadata = {
24
-
object_name : string;
25
-
object_id : string;
26
-
center_name : string;
27
-
ref_frame : string;
28
-
time_system : string;
29
-
start_time : string;
30
-
stop_time : string;
31
-
useable_start_time : string option;
32
-
useable_stop_time : string option;
33
-
interpolation : string option;
34
-
interpolation_degree : int option;
35
-
}
36
-
(** OEM segment metadata. *)
37
-
38
-
type covariance_entry = {
39
-
cov_epoch : string;
40
-
cov_ref_frame : string;
41
-
cov : float array; (** Lower triangle of 6x6 covariance (21 elements). *)
42
-
}
43
-
(** Covariance at a specific epoch. Lower triangle stored row-by-row:
44
-
[C11, C21, C22, C31, C32, C33, ...]. Units match the OEM position/velocity
45
-
(typically km^2, km^2/s, km^2/s^2). *)
46
-
47
-
type segment = {
48
-
metadata : metadata;
49
-
data : state_vector array;
50
-
covariances : covariance_entry list;
51
-
comments : string list;
52
-
}
53
-
(** An OEM segment: metadata, state vectors, covariances, and comments. *)
54
-
55
-
type header = {
56
-
ccsds_oem_vers : string;
57
-
creation_date : string;
58
-
originator : string;
59
-
comments : string list;
60
-
}
61
-
(** OEM file header. *)
62
-
63
-
type t = { header : header; segments : segment list }
64
-
(** A complete OEM file. *)
65
-
66
-
(** {1 Errors} *)
67
-
68
-
type error =
69
-
| Missing_header
70
-
| Missing_metadata
71
-
| Bad_line of { line : int; content : string }
72
-
| Parse_error of string
3
+
This module groups the orbit data message types defined in CCSDS 502.0-B:
73
4
74
-
val pp_error : error Fmt.t
75
-
(** [pp_error] pretty-prints a parse error. *)
5
+
- {!module:Oem}: Orbit Ephemeris Message (OEM)
6
+
- {!module:Opm}: Orbit Parameter Message (OPM)
76
7
77
-
(** {1 KVN Parsing} *)
8
+
For backward compatibility, the OEM types and functions are also re-exported
9
+
at the top level of this module. New code should prefer [Odm.Oem] and
10
+
[Odm.Opm] to access message-specific functionality.
78
11
79
-
val of_kvn_string : string -> (t, error) result
80
-
(** [of_kvn_string s] parses an OEM KVN string. *)
12
+
{b References}:
13
+
- {{:https://public.ccsds.org/Pubs/502x0b3e1.pdf} CCSDS 502.0-B-3} Orbit
14
+
Data Messages *)
81
15
82
-
val of_kvn_channel : in_channel -> (t, error) result
83
-
(** [of_kvn_channel ic] parses OEM KVN from an input channel. *)
16
+
module Oem = Oem
17
+
(** Orbit Ephemeris Message (OEM). *)
84
18
85
-
val of_kvn_file : string -> (t, error) result
86
-
(** [of_kvn_file path] parses an OEM KVN file. *)
19
+
module Opm = Opm
20
+
(** Orbit Parameter Message (OPM). *)
87
21
88
-
(** {1 Pretty-printers} *)
22
+
(** {1 Backward-compatible OEM API}
89
23
90
-
val pp : t Fmt.t
91
-
(** [pp] pretty-prints an OEM. *)
24
+
The following types and values are re-exported from {!Oem} for backward
25
+
compatibility. New code should use [Odm.Oem] directly. *)
92
26
93
-
val pp_header : header Fmt.t
94
-
(** [pp_header] pretty-prints an OEM header. *)
95
-
96
-
val pp_metadata : metadata Fmt.t
97
-
(** [pp_metadata] pretty-prints OEM metadata. *)
98
-
99
-
val pp_state_vector : state_vector Fmt.t
100
-
(** [pp_state_vector] pretty-prints a state vector. *)
101
-
102
-
val pp_segment : segment Fmt.t
103
-
(** [pp_segment] pretty-prints an OEM segment. *)
104
-
105
-
(** {1 Accessors} *)
106
-
107
-
val segments : t -> segment list
108
-
(** [segments t] returns the list of segments. *)
109
-
110
-
val state_vectors : segment -> state_vector array
111
-
(** [state_vectors seg] returns the state vectors of a segment. *)
112
-
113
-
val epoch_range : segment -> string * string
114
-
(** [epoch_range seg] returns [(start_time, stop_time)] from the segment
115
-
metadata. *)
116
-
117
-
val position_at : t -> float -> vec3 option
118
-
(** [position_at oem unix_t] returns the interpolated position at the given Unix
119
-
timestamp. Searches all segments and uses Lagrange polynomial interpolation
120
-
(degree from OEM metadata, default 7). Returns [None] if [unix_t] is outside
121
-
all segment ranges.
122
-
123
-
This is the main entry point for querying an OEM. *)
124
-
125
-
val interpolate : segment -> float -> vec3 option
126
-
(** [interpolate seg unix_t] interpolates within a single segment. Use
127
-
{!position_at} unless you need to work with a specific segment. *)
27
+
include module type of Oem
+455
lib/oem.ml
+455
lib/oem.ml
···
1
+
(** Orbit Ephemeris Message (OEM) — CCSDS 502.0-B-3. *)
2
+
3
+
type vec3 = Vec3.t = { x : float; y : float; z : float }
4
+
5
+
type state_vector = {
6
+
epoch : string;
7
+
pos : vec3;
8
+
vel : vec3;
9
+
accel : vec3 option;
10
+
}
11
+
12
+
type metadata = {
13
+
object_name : string;
14
+
object_id : string;
15
+
center_name : string;
16
+
ref_frame : string;
17
+
time_system : string;
18
+
start_time : string;
19
+
stop_time : string;
20
+
useable_start_time : string option;
21
+
useable_stop_time : string option;
22
+
interpolation : string option;
23
+
interpolation_degree : int option;
24
+
}
25
+
26
+
type covariance_entry = {
27
+
cov_epoch : string;
28
+
cov_ref_frame : string;
29
+
cov : float array;
30
+
}
31
+
32
+
type segment = {
33
+
metadata : metadata;
34
+
data : state_vector array;
35
+
covariances : covariance_entry list;
36
+
comments : string list;
37
+
}
38
+
39
+
type header = {
40
+
ccsds_oem_vers : string;
41
+
creation_date : string;
42
+
originator : string;
43
+
comments : string list;
44
+
}
45
+
46
+
type t = { header : header; segments : segment list }
47
+
48
+
type error =
49
+
| Missing_header
50
+
| Missing_metadata
51
+
| Bad_line of { line : int; content : string }
52
+
| Parse_error of string
53
+
54
+
let pp_error ppf = function
55
+
| Missing_header -> Fmt.pf ppf "missing OEM header"
56
+
| Missing_metadata -> Fmt.pf ppf "missing META_START"
57
+
| Bad_line { line; content } -> Fmt.pf ppf "bad line %d: %s" line content
58
+
| Parse_error msg -> Fmt.pf ppf "parse error: %s" msg
59
+
60
+
(* Pretty-printers *)
61
+
62
+
let pp_vec3 ppf v = Fmt.pf ppf "(%.6f, %.6f, %.6f)" v.x v.y v.z
63
+
64
+
let pp_state_vector ppf sv =
65
+
Fmt.pf ppf "%s pos=%a vel=%a" sv.epoch pp_vec3 sv.pos pp_vec3 sv.vel;
66
+
match sv.accel with None -> () | Some a -> Fmt.pf ppf " accel=%a" pp_vec3 a
67
+
68
+
let pp_metadata ppf m =
69
+
Fmt.pf ppf
70
+
"@[<v>OBJECT_NAME = %s@,\
71
+
OBJECT_ID = %s@,\
72
+
CENTER_NAME = %s@,\
73
+
REF_FRAME = %s@,\
74
+
TIME_SYSTEM = %s@,\
75
+
START_TIME = %s@,\
76
+
STOP_TIME = %s@]"
77
+
m.object_name m.object_id m.center_name m.ref_frame m.time_system
78
+
m.start_time m.stop_time
79
+
80
+
let pp_segment ppf seg =
81
+
Fmt.pf ppf "@[<v>META:@, %a@,DATA: %d vectors@]" pp_metadata seg.metadata
82
+
(Array.length seg.data)
83
+
84
+
let pp_header ppf h =
85
+
Fmt.pf ppf "CCSDS_OEM_VERS = %s@,CREATION_DATE = %s@,ORIGINATOR = %s"
86
+
h.ccsds_oem_vers h.creation_date h.originator
87
+
88
+
let pp ppf t =
89
+
Fmt.pf ppf "@[<v>%a@,%a@]" pp_header t.header
90
+
Fmt.(list ~sep:(Fmt.any "@,") pp_segment)
91
+
t.segments
92
+
93
+
(* Accessors *)
94
+
95
+
let segments t = t.segments
96
+
let state_vectors seg = seg.data
97
+
let epoch_range seg = (seg.metadata.start_time, seg.metadata.stop_time)
98
+
99
+
(* Parsing helpers *)
100
+
101
+
let trim s = String.trim s
102
+
103
+
let split_kv line =
104
+
match String.index_opt line '=' with
105
+
| None -> None
106
+
| Some i ->
107
+
let key = trim (String.sub line 0 i) in
108
+
let value = trim (String.sub line (i + 1) (String.length line - i - 1)) in
109
+
Some (key, value)
110
+
111
+
let is_data_line s =
112
+
let s = trim s in
113
+
String.length s > 0
114
+
&&
115
+
let c = s.[0] in
116
+
(c >= '0' && c <= '9') || c = '-'
117
+
118
+
let split_spaces s =
119
+
String.split_on_char ' ' s |> List.filter (fun s -> String.length s > 0)
120
+
121
+
let parse_state_vector line_num line =
122
+
let tokens = split_spaces (trim line) in
123
+
match tokens with
124
+
| epoch :: rest -> (
125
+
let floats =
126
+
List.map
127
+
(fun s ->
128
+
match float_of_string_opt s with Some f -> f | None -> Float.nan)
129
+
rest
130
+
in
131
+
match floats with
132
+
| [ x; y; z; vx; vy; vz ] ->
133
+
Ok
134
+
{
135
+
epoch;
136
+
pos = { x; y; z };
137
+
vel = { x = vx; y = vy; z = vz };
138
+
accel = None;
139
+
}
140
+
| [ x; y; z; vx; vy; vz; ax; ay; az ] ->
141
+
Ok
142
+
{
143
+
epoch;
144
+
pos = { x; y; z };
145
+
vel = { x = vx; y = vy; z = vz };
146
+
accel = Some { x = ax; y = ay; z = az };
147
+
}
148
+
| _ -> Error (Bad_line { line = line_num; content = line }))
149
+
| [] -> Error (Bad_line { line = line_num; content = line })
150
+
151
+
let empty_metadata =
152
+
{
153
+
object_name = "";
154
+
object_id = "";
155
+
center_name = "";
156
+
ref_frame = "";
157
+
time_system = "";
158
+
start_time = "";
159
+
stop_time = "";
160
+
useable_start_time = None;
161
+
useable_stop_time = None;
162
+
interpolation = None;
163
+
interpolation_degree = None;
164
+
}
165
+
166
+
let set_meta_field meta key value =
167
+
match key with
168
+
| "OBJECT_NAME" -> { meta with object_name = value }
169
+
| "OBJECT_ID" -> { meta with object_id = value }
170
+
| "CENTER_NAME" -> { meta with center_name = value }
171
+
| "REF_FRAME" -> { meta with ref_frame = value }
172
+
| "TIME_SYSTEM" -> { meta with time_system = value }
173
+
| "START_TIME" -> { meta with start_time = value }
174
+
| "STOP_TIME" -> { meta with stop_time = value }
175
+
| "USEABLE_START_TIME" -> { meta with useable_start_time = Some value }
176
+
| "USEABLE_STOP_TIME" -> { meta with useable_stop_time = Some value }
177
+
| "INTERPOLATION" -> { meta with interpolation = Some value }
178
+
| "INTERPOLATION_DEGREE" -> (
179
+
match int_of_string_opt value with
180
+
| Some d -> { meta with interpolation_degree = Some d }
181
+
| None -> meta)
182
+
| _ -> meta
183
+
184
+
type parse_state = Header | Meta | Data | Covariance
185
+
186
+
type parse_ctx = {
187
+
mutable state : parse_state;
188
+
mutable header_vers : string;
189
+
mutable header_date : string;
190
+
mutable header_orig : string;
191
+
mutable header_comments : string list;
192
+
mutable cur_meta : metadata;
193
+
mutable cur_data : state_vector list;
194
+
mutable cur_covs : covariance_entry list;
195
+
mutable cur_cov_epoch : string;
196
+
mutable cur_cov_frame : string;
197
+
mutable cur_cov_values : float list;
198
+
mutable cur_comments : string list;
199
+
mutable segments_acc : segment list;
200
+
mutable has_header : bool;
201
+
mutable has_meta : bool;
202
+
mutable err : error option;
203
+
mutable line_num : int;
204
+
}
205
+
206
+
let extract_comment trimmed =
207
+
if String.length trimmed > 8 then
208
+
trim (String.sub trimmed 8 (String.length trimmed - 8))
209
+
else ""
210
+
211
+
let is_comment trimmed =
212
+
String.length trimmed >= 7 && String.sub trimmed 0 7 = "COMMENT"
213
+
214
+
let finish_cov_entry ctx =
215
+
if ctx.cur_cov_epoch <> "" && ctx.cur_cov_values <> [] then begin
216
+
let entry =
217
+
{
218
+
cov_epoch = ctx.cur_cov_epoch;
219
+
cov_ref_frame = ctx.cur_cov_frame;
220
+
cov = Array.of_list ctx.cur_cov_values;
221
+
}
222
+
in
223
+
ctx.cur_covs <- entry :: ctx.cur_covs;
224
+
ctx.cur_cov_epoch <- "";
225
+
ctx.cur_cov_frame <- "";
226
+
ctx.cur_cov_values <- []
227
+
end
228
+
229
+
let finish_segment ctx =
230
+
let seg =
231
+
{
232
+
metadata = ctx.cur_meta;
233
+
data = Array.of_list (List.rev ctx.cur_data);
234
+
covariances = List.rev ctx.cur_covs;
235
+
comments = List.rev ctx.cur_comments;
236
+
}
237
+
in
238
+
ctx.segments_acc <- seg :: ctx.segments_acc;
239
+
ctx.cur_data <- [];
240
+
ctx.cur_covs <- [];
241
+
ctx.cur_comments <- []
242
+
243
+
let process_header ctx trimmed =
244
+
if is_comment trimmed then
245
+
ctx.header_comments <- extract_comment trimmed :: ctx.header_comments
246
+
else if trimmed = "META_START" then begin
247
+
ctx.has_meta <- true;
248
+
ctx.state <- Meta;
249
+
ctx.cur_meta <- empty_metadata
250
+
end
251
+
else
252
+
match split_kv trimmed with
253
+
| Some ("CCSDS_OEM_VERS", v) ->
254
+
ctx.has_header <- true;
255
+
ctx.header_vers <- v
256
+
| Some ("CREATION_DATE", v) -> ctx.header_date <- v
257
+
| Some ("ORIGINATOR", v) -> ctx.header_orig <- v
258
+
| _ -> ()
259
+
260
+
let process_meta ctx trimmed =
261
+
if trimmed = "META_STOP" then ctx.state <- Data
262
+
else
263
+
match split_kv trimmed with
264
+
| Some (k, v) -> ctx.cur_meta <- set_meta_field ctx.cur_meta k v
265
+
| None -> ()
266
+
267
+
let process_data ctx trimmed =
268
+
if is_comment trimmed then
269
+
ctx.cur_comments <- extract_comment trimmed :: ctx.cur_comments
270
+
else if trimmed = "META_START" then begin
271
+
finish_segment ctx;
272
+
ctx.state <- Meta;
273
+
ctx.cur_meta <- empty_metadata
274
+
end
275
+
else if trimmed = "COVARIANCE_START" then ctx.state <- Covariance
276
+
else if is_data_line trimmed then
277
+
match parse_state_vector ctx.line_num trimmed with
278
+
| Ok sv -> ctx.cur_data <- sv :: ctx.cur_data
279
+
| Error e -> ctx.err <- Some e
280
+
else ()
281
+
282
+
let process_covariance ctx trimmed =
283
+
if trimmed = "COVARIANCE_STOP" then begin
284
+
finish_cov_entry ctx;
285
+
ctx.state <- Data
286
+
end
287
+
else if is_comment trimmed then ()
288
+
else
289
+
match split_kv trimmed with
290
+
| Some ("EPOCH", v) ->
291
+
finish_cov_entry ctx;
292
+
ctx.cur_cov_epoch <- v
293
+
| Some ("COV_REF_FRAME", v) -> ctx.cur_cov_frame <- v
294
+
| _ ->
295
+
(* Data line: parse floats (lower triangle row) *)
296
+
let floats =
297
+
split_spaces trimmed
298
+
|> List.filter_map (fun s -> float_of_string_opt s)
299
+
in
300
+
ctx.cur_cov_values <- ctx.cur_cov_values @ floats
301
+
302
+
let parse_lines lines =
303
+
let ctx =
304
+
{
305
+
state = Header;
306
+
header_vers = "";
307
+
header_date = "";
308
+
header_orig = "";
309
+
header_comments = [];
310
+
cur_meta = empty_metadata;
311
+
cur_data = [];
312
+
cur_covs = [];
313
+
cur_cov_epoch = "";
314
+
cur_cov_frame = "";
315
+
cur_cov_values = [];
316
+
cur_comments = [];
317
+
segments_acc = [];
318
+
has_header = false;
319
+
has_meta = false;
320
+
err = None;
321
+
line_num = 0;
322
+
}
323
+
in
324
+
List.iter
325
+
(fun line ->
326
+
ctx.line_num <- ctx.line_num + 1;
327
+
if ctx.err <> None then ()
328
+
else
329
+
let trimmed = trim line in
330
+
if String.length trimmed = 0 then ()
331
+
else
332
+
match ctx.state with
333
+
| Header -> process_header ctx trimmed
334
+
| Meta -> process_meta ctx trimmed
335
+
| Data -> process_data ctx trimmed
336
+
| Covariance -> process_covariance ctx trimmed)
337
+
lines;
338
+
match ctx.err with
339
+
| Some e -> Error e
340
+
| None ->
341
+
if not ctx.has_header then Error Missing_header
342
+
else if not ctx.has_meta then Error Missing_metadata
343
+
else begin
344
+
(match ctx.state with
345
+
| Data | Covariance -> finish_segment ctx
346
+
| _ -> ());
347
+
Ok
348
+
{
349
+
header =
350
+
{
351
+
ccsds_oem_vers = ctx.header_vers;
352
+
creation_date = ctx.header_date;
353
+
originator = ctx.header_orig;
354
+
comments = List.rev ctx.header_comments;
355
+
};
356
+
segments = List.rev ctx.segments_acc;
357
+
}
358
+
end
359
+
360
+
let of_kvn_string s =
361
+
let lines = String.split_on_char '\n' s in
362
+
parse_lines lines
363
+
364
+
let of_kvn_channel ic =
365
+
let lines = ref [] in
366
+
(try
367
+
while true do
368
+
lines := input_line ic :: !lines
369
+
done
370
+
with End_of_file -> ());
371
+
parse_lines (List.rev !lines)
372
+
373
+
let of_kvn_file path =
374
+
let ic = open_in path in
375
+
let result = of_kvn_channel ic in
376
+
close_in ic;
377
+
result
378
+
379
+
(* Interpolation *)
380
+
381
+
let epoch_to_unix epoch =
382
+
(* Parse ISO 8601 timestamp to unix timestamp *)
383
+
match Ptime.of_rfc3339 (epoch ^ "Z") with
384
+
| Ok (t, _, _) -> Some (Ptime.to_float_s t)
385
+
| Error _ -> (
386
+
(* Try without the Z suffix in case it already has timezone *)
387
+
match Ptime.of_rfc3339 epoch with
388
+
| Ok (t, _, _) -> Some (Ptime.to_float_s t)
389
+
| Error _ -> None)
390
+
391
+
(** Lagrange polynomial interpolation of vec3 over a window of data points.
392
+
[times] has length [k], [positions] has length [k], [t] is the query time.
393
+
*)
394
+
let lagrange_vec3 times positions t =
395
+
let k = Array.length times in
396
+
let x = ref 0.0 and y = ref 0.0 and z = ref 0.0 in
397
+
for j = 0 to k - 1 do
398
+
let basis = ref 1.0 in
399
+
for m = 0 to k - 1 do
400
+
if m <> j then
401
+
basis := !basis *. (t -. times.(m)) /. (times.(j) -. times.(m))
402
+
done;
403
+
x := !x +. (!basis *. positions.(j).x);
404
+
y := !y +. (!basis *. positions.(j).y);
405
+
z := !z +. (!basis *. positions.(j).z)
406
+
done;
407
+
{ x = !x; y = !y; z = !z }
408
+
409
+
let interpolate seg unix_t =
410
+
let data = seg.data in
411
+
let n = Array.length data in
412
+
let degree =
413
+
match seg.metadata.interpolation_degree with Some d -> d | None -> 7
414
+
in
415
+
if n < 2 then None
416
+
else
417
+
(* Convert all epochs to unix timestamps *)
418
+
let times =
419
+
Array.map
420
+
(fun sv ->
421
+
match epoch_to_unix sv.epoch with Some t -> t | None -> Float.nan)
422
+
data
423
+
in
424
+
if Array.exists Float.is_nan times then None
425
+
else
426
+
let t0 = times.(0) and tn = times.(n - 1) in
427
+
if unix_t < t0 || unix_t > tn then None
428
+
else
429
+
(* Binary search for bracketing interval *)
430
+
let lo = ref 0 and hi = ref (n - 2) in
431
+
while !hi - !lo > 1 do
432
+
let mid = (!lo + !hi) / 2 in
433
+
if times.(mid) <= unix_t then lo := mid else hi := mid
434
+
done;
435
+
let i =
436
+
if times.(!lo) <= unix_t && unix_t <= times.(!lo + 1) then !lo
437
+
else !lo + 1
438
+
in
439
+
(* Select centered window of degree+1 points around interval [i, i+1] *)
440
+
let needed = min (degree + 1) n in
441
+
let half = (needed - 2) / 2 in
442
+
let start = max 0 (min (i - half) (n - needed)) in
443
+
let win_t = Array.sub times start needed in
444
+
let win_p = Array.init needed (fun j -> data.(start + j).pos) in
445
+
Some (lagrange_vec3 win_t win_p unix_t)
446
+
447
+
let position_at oem unix_t =
448
+
let rec try_segments = function
449
+
| [] -> None
450
+
| seg :: rest -> (
451
+
match interpolate seg unix_t with
452
+
| Some _ as result -> result
453
+
| None -> try_segments rest)
454
+
in
455
+
try_segments oem.segments
+128
lib/oem.mli
+128
lib/oem.mli
···
1
+
(** Orbit Ephemeris Message (OEM) — CCSDS 502.0-B-3.
2
+
3
+
Parse and manipulate Orbit Ephemeris Messages (OEM) in KVN format. Supports
4
+
multi-segment files, optional acceleration data, and Lagrange polynomial
5
+
interpolation.
6
+
7
+
{b References}:
8
+
- CCSDS 502.0-B-3, Orbit Data Messages *)
9
+
10
+
(** {1 Types} *)
11
+
12
+
type vec3 = Vec3.t = { x : float; y : float; z : float }
13
+
(** 3D vector (km, km/s, or km/s²). *)
14
+
15
+
type state_vector = {
16
+
epoch : string;
17
+
pos : vec3;
18
+
vel : vec3;
19
+
accel : vec3 option;
20
+
}
21
+
(** Cartesian state vector with epoch. Position in km, velocity in km/s,
22
+
acceleration in km/s² (optional). *)
23
+
24
+
type metadata = {
25
+
object_name : string;
26
+
object_id : string;
27
+
center_name : string;
28
+
ref_frame : string;
29
+
time_system : string;
30
+
start_time : string;
31
+
stop_time : string;
32
+
useable_start_time : string option;
33
+
useable_stop_time : string option;
34
+
interpolation : string option;
35
+
interpolation_degree : int option;
36
+
}
37
+
(** OEM segment metadata. *)
38
+
39
+
type covariance_entry = {
40
+
cov_epoch : string;
41
+
cov_ref_frame : string;
42
+
cov : float array; (** Lower triangle of 6x6 covariance (21 elements). *)
43
+
}
44
+
(** Covariance at a specific epoch. Lower triangle stored row-by-row:
45
+
[C11, C21, C22, C31, C32, C33, ...]. Units match the OEM position/velocity
46
+
(typically km^2, km^2/s, km^2/s^2). *)
47
+
48
+
type segment = {
49
+
metadata : metadata;
50
+
data : state_vector array;
51
+
covariances : covariance_entry list;
52
+
comments : string list;
53
+
}
54
+
(** An OEM segment: metadata, state vectors, covariances, and comments. *)
55
+
56
+
type header = {
57
+
ccsds_oem_vers : string;
58
+
creation_date : string;
59
+
originator : string;
60
+
comments : string list;
61
+
}
62
+
(** OEM file header. *)
63
+
64
+
type t = { header : header; segments : segment list }
65
+
(** A complete OEM file. *)
66
+
67
+
(** {1 Errors} *)
68
+
69
+
type error =
70
+
| Missing_header
71
+
| Missing_metadata
72
+
| Bad_line of { line : int; content : string }
73
+
| Parse_error of string
74
+
75
+
val pp_error : error Fmt.t
76
+
(** [pp_error] pretty-prints a parse error. *)
77
+
78
+
(** {1 KVN Parsing} *)
79
+
80
+
val of_kvn_string : string -> (t, error) result
81
+
(** [of_kvn_string s] parses an OEM KVN string. *)
82
+
83
+
val of_kvn_channel : in_channel -> (t, error) result
84
+
(** [of_kvn_channel ic] parses OEM KVN from an input channel. *)
85
+
86
+
val of_kvn_file : string -> (t, error) result
87
+
(** [of_kvn_file path] parses an OEM KVN file. *)
88
+
89
+
(** {1 Pretty-printers} *)
90
+
91
+
val pp : t Fmt.t
92
+
(** [pp] pretty-prints an OEM. *)
93
+
94
+
val pp_header : header Fmt.t
95
+
(** [pp_header] pretty-prints an OEM header. *)
96
+
97
+
val pp_metadata : metadata Fmt.t
98
+
(** [pp_metadata] pretty-prints OEM metadata. *)
99
+
100
+
val pp_state_vector : state_vector Fmt.t
101
+
(** [pp_state_vector] pretty-prints a state vector. *)
102
+
103
+
val pp_segment : segment Fmt.t
104
+
(** [pp_segment] pretty-prints an OEM segment. *)
105
+
106
+
(** {1 Accessors} *)
107
+
108
+
val segments : t -> segment list
109
+
(** [segments t] returns the list of segments. *)
110
+
111
+
val state_vectors : segment -> state_vector array
112
+
(** [state_vectors seg] returns the state vectors of a segment. *)
113
+
114
+
val epoch_range : segment -> string * string
115
+
(** [epoch_range seg] returns [(start_time, stop_time)] from the segment
116
+
metadata. *)
117
+
118
+
val position_at : t -> float -> vec3 option
119
+
(** [position_at oem unix_t] returns the interpolated position at the given Unix
120
+
timestamp. Searches all segments and uses Lagrange polynomial interpolation
121
+
(degree from OEM metadata, default 7). Returns [None] if [unix_t] is outside
122
+
all segment ranges.
123
+
124
+
This is the main entry point for querying an OEM. *)
125
+
126
+
val interpolate : segment -> float -> vec3 option
127
+
(** [interpolate seg unix_t] interpolates within a single segment. Use
128
+
{!position_at} unless you need to work with a specific segment. *)
+447
lib/opm.ml
+447
lib/opm.ml
···
1
+
(*---------------------------------------------------------------------------
2
+
Copyright (c) 2025 Thomas Gazagnaire. All rights reserved.
3
+
SPDX-License-Identifier: ISC
4
+
---------------------------------------------------------------------------*)
5
+
6
+
(** CCSDS 502.0-B Orbit Parameter Message (OPM) parser and serializer. *)
7
+
8
+
(* ------------------------------------------------------------------ *)
9
+
(* Types *)
10
+
(* ------------------------------------------------------------------ *)
11
+
12
+
type keplerian = {
13
+
semi_major_axis : float;
14
+
eccentricity : float;
15
+
inclination : float;
16
+
ra_of_asc_node : float;
17
+
arg_of_pericenter : float;
18
+
true_anomaly : float option;
19
+
mean_anomaly : float option;
20
+
gm : float option;
21
+
}
22
+
23
+
type spacecraft_parameters = {
24
+
mass : float option;
25
+
solar_rad_area : float option;
26
+
solar_rad_coeff : float option;
27
+
drag_area : float option;
28
+
drag_coeff : float option;
29
+
}
30
+
31
+
type cartesian = {
32
+
epoch : Ptime.t;
33
+
x : float;
34
+
y : float;
35
+
z : float;
36
+
x_dot : float;
37
+
y_dot : float;
38
+
z_dot : float;
39
+
}
40
+
41
+
type state = Cartesian of cartesian | Keplerian of keplerian
42
+
43
+
type maneuver = {
44
+
man_epoch_ignition : Ptime.t;
45
+
man_duration : float;
46
+
man_delta_mass : float;
47
+
man_ref_frame : string;
48
+
man_dv_1 : float;
49
+
man_dv_2 : float;
50
+
man_dv_3 : float;
51
+
}
52
+
53
+
type covariance = {
54
+
cov_ref_frame : string option;
55
+
cx_x : float;
56
+
cy_x : float;
57
+
cy_y : float;
58
+
cz_x : float;
59
+
cz_y : float;
60
+
cz_z : float;
61
+
cx_dot_x : float;
62
+
cx_dot_y : float;
63
+
cx_dot_z : float;
64
+
cx_dot_x_dot : float;
65
+
cy_dot_x : float;
66
+
cy_dot_y : float;
67
+
cy_dot_z : float;
68
+
cy_dot_x_dot : float;
69
+
cy_dot_y_dot : float;
70
+
cz_dot_x : float;
71
+
cz_dot_y : float;
72
+
cz_dot_z : float;
73
+
cz_dot_x_dot : float;
74
+
cz_dot_y_dot : float;
75
+
cz_dot_z_dot : float;
76
+
}
77
+
78
+
type metadata = {
79
+
object_name : string;
80
+
object_id : string;
81
+
center_name : string;
82
+
ref_frame : string;
83
+
time_system : string;
84
+
}
85
+
86
+
type header = { version : string; creation_date : string; originator : string }
87
+
88
+
type t = {
89
+
header : header;
90
+
metadata : metadata;
91
+
epoch : Ptime.t;
92
+
state : state;
93
+
spacecraft : spacecraft_parameters option;
94
+
covariance : covariance option;
95
+
maneuvers : maneuver list;
96
+
}
97
+
98
+
type error =
99
+
| Unexpected_eof
100
+
| Bad_keyword of { line : int; got : string }
101
+
| Bad_epoch of { line : int; value : string }
102
+
| Bad_float of { line : int; value : string }
103
+
| Missing_keyword of string
104
+
| Parse_error of string
105
+
106
+
let pp_error ppf = function
107
+
| Unexpected_eof -> Fmt.pf ppf "Unexpected end of file"
108
+
| Bad_keyword { line; got } -> Fmt.pf ppf "Line %d: bad keyword %S" line got
109
+
| Bad_epoch { line; value } -> Fmt.pf ppf "Line %d: bad epoch %S" line value
110
+
| Bad_float { line; value } -> Fmt.pf ppf "Line %d: bad float %S" line value
111
+
| Missing_keyword kw -> Fmt.pf ppf "Missing required keyword %S" kw
112
+
| Parse_error msg -> Fmt.pf ppf "Parse error: %s" msg
113
+
114
+
(* ------------------------------------------------------------------ *)
115
+
(* KVN helpers *)
116
+
(* ------------------------------------------------------------------ *)
117
+
118
+
let strip_unit s =
119
+
let s = String.trim s in
120
+
match String.rindex_opt s ']' with
121
+
| None -> s
122
+
| Some ri -> (
123
+
match String.rindex_opt s '[' with
124
+
| None -> s
125
+
| Some li -> if li < ri then String.trim (String.sub s 0 li) else s)
126
+
127
+
let float_of v = float_of_string_opt (strip_unit v)
128
+
let float_or_zero v = match float_of v with Some f -> f | None -> 0.0
129
+
130
+
(* ------------------------------------------------------------------ *)
131
+
(* Parsing *)
132
+
(* ------------------------------------------------------------------ *)
133
+
134
+
let parse_kvn_pairs s =
135
+
let lines = String.split_on_char '\n' s in
136
+
let pairs = ref [] in
137
+
List.iter
138
+
(fun line ->
139
+
let line = String.trim line in
140
+
if
141
+
line = "" || (String.length line >= 7 && String.sub line 0 7 = "COMMENT")
142
+
then ()
143
+
else
144
+
match String.index_opt line '=' with
145
+
| None -> ()
146
+
| Some eq ->
147
+
let key = String.trim (String.sub line 0 eq) in
148
+
let value =
149
+
strip_unit
150
+
(String.sub line (eq + 1) (String.length line - eq - 1))
151
+
in
152
+
pairs := (key, value) :: !pairs)
153
+
lines;
154
+
List.rev !pairs
155
+
156
+
let find key pairs = List.assoc_opt key pairs
157
+
158
+
let find_epoch key pairs =
159
+
match find key pairs with
160
+
| Some v -> (
161
+
match Kvn.parse_epoch v with Some t -> t | None -> Ptime.epoch)
162
+
| None -> Ptime.epoch
163
+
164
+
let find_float key pairs =
165
+
match find key pairs with Some v -> float_of v | None -> None
166
+
167
+
let find_float_or key default pairs =
168
+
match find_float key pairs with Some f -> f | None -> default
169
+
170
+
let parse_header pairs =
171
+
{
172
+
version =
173
+
(match find "CCSDS_OPM_VERS" pairs with Some v -> v | None -> "");
174
+
creation_date =
175
+
(match find "CREATION_DATE" pairs with Some v -> v | None -> "");
176
+
originator = (match find "ORIGINATOR" pairs with Some v -> v | None -> "");
177
+
}
178
+
179
+
let parse_metadata pairs =
180
+
{
181
+
object_name =
182
+
(match find "OBJECT_NAME" pairs with Some v -> v | None -> "");
183
+
object_id = (match find "OBJECT_ID" pairs with Some v -> v | None -> "");
184
+
center_name =
185
+
(match find "CENTER_NAME" pairs with Some v -> v | None -> "EARTH");
186
+
ref_frame =
187
+
(match find "REF_FRAME" pairs with Some v -> v | None -> "EME2000");
188
+
time_system =
189
+
(match find "TIME_SYSTEM" pairs with Some v -> v | None -> "UTC");
190
+
}
191
+
192
+
let has_keplerian pairs =
193
+
find "SEMI_MAJOR_AXIS" pairs <> None || find "ECCENTRICITY" pairs <> None
194
+
195
+
let parse_keplerian pairs =
196
+
{
197
+
semi_major_axis = find_float_or "SEMI_MAJOR_AXIS" 0.0 pairs;
198
+
eccentricity = find_float_or "ECCENTRICITY" 0.0 pairs;
199
+
inclination = find_float_or "INCLINATION" 0.0 pairs;
200
+
ra_of_asc_node = find_float_or "RA_OF_ASC_NODE" 0.0 pairs;
201
+
arg_of_pericenter = find_float_or "ARG_OF_PERICENTER" 0.0 pairs;
202
+
true_anomaly = find_float "TRUE_ANOMALY" pairs;
203
+
mean_anomaly = find_float "MEAN_ANOMALY" pairs;
204
+
gm = find_float "GM" pairs;
205
+
}
206
+
207
+
let parse_cartesian pairs epoch =
208
+
{
209
+
epoch;
210
+
x = find_float_or "X" 0.0 pairs;
211
+
y = find_float_or "Y" 0.0 pairs;
212
+
z = find_float_or "Z" 0.0 pairs;
213
+
x_dot = find_float_or "X_DOT" 0.0 pairs;
214
+
y_dot = find_float_or "Y_DOT" 0.0 pairs;
215
+
z_dot = find_float_or "Z_DOT" 0.0 pairs;
216
+
}
217
+
218
+
let parse_spacecraft pairs =
219
+
let mass = find_float "MASS" pairs in
220
+
let solar_rad_area = find_float "SOLAR_RAD_AREA" pairs in
221
+
let solar_rad_coeff = find_float "SOLAR_RAD_COEFF" pairs in
222
+
let drag_area = find_float "DRAG_AREA" pairs in
223
+
let drag_coeff = find_float "DRAG_COEFF" pairs in
224
+
match (mass, solar_rad_area, solar_rad_coeff, drag_area, drag_coeff) with
225
+
| None, None, None, None, None -> None
226
+
| _ -> Some { mass; solar_rad_area; solar_rad_coeff; drag_area; drag_coeff }
227
+
228
+
let parse_covariance pairs =
229
+
if find "CX_X" pairs = None then None
230
+
else
231
+
Some
232
+
{
233
+
cov_ref_frame = find "COV_REF_FRAME" pairs;
234
+
cx_x = find_float_or "CX_X" 0.0 pairs;
235
+
cy_x = find_float_or "CY_X" 0.0 pairs;
236
+
cy_y = find_float_or "CY_Y" 0.0 pairs;
237
+
cz_x = find_float_or "CZ_X" 0.0 pairs;
238
+
cz_y = find_float_or "CZ_Y" 0.0 pairs;
239
+
cz_z = find_float_or "CZ_Z" 0.0 pairs;
240
+
cx_dot_x = find_float_or "CX_DOT_X" 0.0 pairs;
241
+
cx_dot_y = find_float_or "CX_DOT_Y" 0.0 pairs;
242
+
cx_dot_z = find_float_or "CX_DOT_Z" 0.0 pairs;
243
+
cx_dot_x_dot = find_float_or "CX_DOT_X_DOT" 0.0 pairs;
244
+
cy_dot_x = find_float_or "CY_DOT_X" 0.0 pairs;
245
+
cy_dot_y = find_float_or "CY_DOT_Y" 0.0 pairs;
246
+
cy_dot_z = find_float_or "CY_DOT_Z" 0.0 pairs;
247
+
cy_dot_x_dot = find_float_or "CY_DOT_X_DOT" 0.0 pairs;
248
+
cy_dot_y_dot = find_float_or "CY_DOT_Y_DOT" 0.0 pairs;
249
+
cz_dot_x = find_float_or "CZ_DOT_X" 0.0 pairs;
250
+
cz_dot_y = find_float_or "CZ_DOT_Y" 0.0 pairs;
251
+
cz_dot_z = find_float_or "CZ_DOT_Z" 0.0 pairs;
252
+
cz_dot_x_dot = find_float_or "CZ_DOT_X_DOT" 0.0 pairs;
253
+
cz_dot_y_dot = find_float_or "CZ_DOT_Y_DOT" 0.0 pairs;
254
+
cz_dot_z_dot = find_float_or "CZ_DOT_Z_DOT" 0.0 pairs;
255
+
}
256
+
257
+
let parse_maneuvers pairs =
258
+
(* Collect all MAN_EPOCH_IGNITION entries; each starts a new maneuver.
259
+
Since KVN pairs are in order, we group maneuver fields by scanning
260
+
for the epoch keyword. *)
261
+
let mans = ref [] in
262
+
let cur = Hashtbl.create 8 in
263
+
let flush () =
264
+
if Hashtbl.mem cur "MAN_EPOCH_IGNITION" then begin
265
+
let get k = try Hashtbl.find cur k with Not_found -> "" in
266
+
let getf k = float_or_zero (get k) in
267
+
let epoch =
268
+
match Kvn.parse_epoch (get "MAN_EPOCH_IGNITION") with
269
+
| Some t -> t
270
+
| None -> Ptime.epoch
271
+
in
272
+
mans :=
273
+
{
274
+
man_epoch_ignition = epoch;
275
+
man_duration = getf "MAN_DURATION";
276
+
man_delta_mass = getf "MAN_DELTA_MASS";
277
+
man_ref_frame = get "MAN_REF_FRAME";
278
+
man_dv_1 = getf "MAN_DV_1";
279
+
man_dv_2 = getf "MAN_DV_2";
280
+
man_dv_3 = getf "MAN_DV_3";
281
+
}
282
+
:: !mans;
283
+
Hashtbl.clear cur
284
+
end
285
+
in
286
+
List.iter
287
+
(fun (k, v) ->
288
+
if String.length k >= 4 && String.sub k 0 4 = "MAN_" then begin
289
+
if k = "MAN_EPOCH_IGNITION" && Hashtbl.mem cur "MAN_EPOCH_IGNITION" then
290
+
flush ();
291
+
Hashtbl.replace cur k v
292
+
end)
293
+
pairs;
294
+
flush ();
295
+
List.rev !mans
296
+
297
+
let of_string s =
298
+
let pairs = parse_kvn_pairs s in
299
+
let header = parse_header pairs in
300
+
let metadata = parse_metadata pairs in
301
+
let epoch = find_epoch "EPOCH" pairs in
302
+
let state =
303
+
if has_keplerian pairs then Keplerian (parse_keplerian pairs)
304
+
else Cartesian (parse_cartesian pairs epoch)
305
+
in
306
+
let spacecraft = parse_spacecraft pairs in
307
+
let covariance = parse_covariance pairs in
308
+
let maneuvers = parse_maneuvers pairs in
309
+
Ok { header; metadata; epoch; state; spacecraft; covariance; maneuvers }
310
+
311
+
let of_channel ic =
312
+
let buf = Buffer.create 4096 in
313
+
(try
314
+
while true do
315
+
Buffer.add_string buf (input_line ic);
316
+
Buffer.add_char buf '\n'
317
+
done
318
+
with End_of_file -> ());
319
+
of_string (Buffer.contents buf)
320
+
321
+
let of_file path =
322
+
let ic = open_in path in
323
+
let r = of_channel ic in
324
+
close_in ic;
325
+
r
326
+
327
+
(* ------------------------------------------------------------------ *)
328
+
(* Serialization *)
329
+
(* ------------------------------------------------------------------ *)
330
+
331
+
let fmt_epoch buf t =
332
+
let (y, m, d), ((hh, mm, ss), _tz) = Ptime.to_date_time t in
333
+
let frac = Ptime.to_float_s t -. floor (Ptime.to_float_s t) in
334
+
Printf.bprintf buf "%04d-%02d-%02dT%02d:%02d:%06.3f" y m d hh mm
335
+
(Float.of_int ss +. frac)
336
+
337
+
let kv buf k v = Printf.bprintf buf "%s = %s\n" k v
338
+
let kvf buf k f = Printf.bprintf buf "%s = %.14g\n" k f
339
+
let kvf_opt buf k = function Some f -> kvf buf k f | None -> ()
340
+
341
+
let kv_epoch buf k t =
342
+
Printf.bprintf buf "%s = " k;
343
+
fmt_epoch buf t;
344
+
Buffer.add_char buf '\n'
345
+
346
+
let to_string opm =
347
+
let buf = Buffer.create 1024 in
348
+
kv buf "CCSDS_OPM_VERS" opm.header.version;
349
+
kv buf "CREATION_DATE" opm.header.creation_date;
350
+
kv buf "ORIGINATOR" opm.header.originator;
351
+
Buffer.add_char buf '\n';
352
+
kv buf "OBJECT_NAME" opm.metadata.object_name;
353
+
kv buf "OBJECT_ID" opm.metadata.object_id;
354
+
kv buf "CENTER_NAME" opm.metadata.center_name;
355
+
kv buf "REF_FRAME" opm.metadata.ref_frame;
356
+
kv buf "TIME_SYSTEM" opm.metadata.time_system;
357
+
Buffer.add_char buf '\n';
358
+
kv_epoch buf "EPOCH" opm.epoch;
359
+
(match opm.state with
360
+
| Cartesian c ->
361
+
kvf buf "X" c.x;
362
+
kvf buf "Y" c.y;
363
+
kvf buf "Z" c.z;
364
+
kvf buf "X_DOT" c.x_dot;
365
+
kvf buf "Y_DOT" c.y_dot;
366
+
kvf buf "Z_DOT" c.z_dot
367
+
| Keplerian ke ->
368
+
kvf buf "SEMI_MAJOR_AXIS" ke.semi_major_axis;
369
+
kvf buf "ECCENTRICITY" ke.eccentricity;
370
+
kvf buf "INCLINATION" ke.inclination;
371
+
kvf buf "RA_OF_ASC_NODE" ke.ra_of_asc_node;
372
+
kvf buf "ARG_OF_PERICENTER" ke.arg_of_pericenter;
373
+
kvf_opt buf "TRUE_ANOMALY" ke.true_anomaly;
374
+
kvf_opt buf "MEAN_ANOMALY" ke.mean_anomaly;
375
+
kvf_opt buf "GM" ke.gm);
376
+
(match opm.spacecraft with
377
+
| None -> ()
378
+
| Some sp ->
379
+
Buffer.add_char buf '\n';
380
+
kvf_opt buf "MASS" sp.mass;
381
+
kvf_opt buf "SOLAR_RAD_AREA" sp.solar_rad_area;
382
+
kvf_opt buf "SOLAR_RAD_COEFF" sp.solar_rad_coeff;
383
+
kvf_opt buf "DRAG_AREA" sp.drag_area;
384
+
kvf_opt buf "DRAG_COEFF" sp.drag_coeff);
385
+
(match opm.covariance with
386
+
| None -> ()
387
+
| Some c ->
388
+
Buffer.add_char buf '\n';
389
+
(match c.cov_ref_frame with
390
+
| Some f -> kv buf "COV_REF_FRAME" f
391
+
| None -> ());
392
+
kvf buf "CX_X" c.cx_x;
393
+
kvf buf "CY_X" c.cy_x;
394
+
kvf buf "CY_Y" c.cy_y;
395
+
kvf buf "CZ_X" c.cz_x;
396
+
kvf buf "CZ_Y" c.cz_y;
397
+
kvf buf "CZ_Z" c.cz_z;
398
+
kvf buf "CX_DOT_X" c.cx_dot_x;
399
+
kvf buf "CX_DOT_Y" c.cx_dot_y;
400
+
kvf buf "CX_DOT_Z" c.cx_dot_z;
401
+
kvf buf "CX_DOT_X_DOT" c.cx_dot_x_dot;
402
+
kvf buf "CY_DOT_X" c.cy_dot_x;
403
+
kvf buf "CY_DOT_Y" c.cy_dot_y;
404
+
kvf buf "CY_DOT_Z" c.cy_dot_z;
405
+
kvf buf "CY_DOT_X_DOT" c.cy_dot_x_dot;
406
+
kvf buf "CY_DOT_Y_DOT" c.cy_dot_y_dot;
407
+
kvf buf "CZ_DOT_X" c.cz_dot_x;
408
+
kvf buf "CZ_DOT_Y" c.cz_dot_y;
409
+
kvf buf "CZ_DOT_Z" c.cz_dot_z;
410
+
kvf buf "CZ_DOT_X_DOT" c.cz_dot_x_dot;
411
+
kvf buf "CZ_DOT_Y_DOT" c.cz_dot_y_dot;
412
+
kvf buf "CZ_DOT_Z_DOT" c.cz_dot_z_dot);
413
+
List.iter
414
+
(fun man ->
415
+
Buffer.add_char buf '\n';
416
+
kv_epoch buf "MAN_EPOCH_IGNITION" man.man_epoch_ignition;
417
+
kvf buf "MAN_DURATION" man.man_duration;
418
+
kvf buf "MAN_DELTA_MASS" man.man_delta_mass;
419
+
kv buf "MAN_REF_FRAME" man.man_ref_frame;
420
+
kvf buf "MAN_DV_1" man.man_dv_1;
421
+
kvf buf "MAN_DV_2" man.man_dv_2;
422
+
kvf buf "MAN_DV_3" man.man_dv_3)
423
+
opm.maneuvers;
424
+
Buffer.contents buf
425
+
426
+
(* ------------------------------------------------------------------ *)
427
+
(* Pretty-printing *)
428
+
(* ------------------------------------------------------------------ *)
429
+
430
+
let pp_header ppf h =
431
+
Fmt.pf ppf "OPM v%s by %s (%s)" h.version h.originator h.creation_date
432
+
433
+
let pp_metadata ppf m =
434
+
Fmt.pf ppf "%s [%s] %s %s %s" m.object_name m.object_id m.center_name
435
+
m.ref_frame m.time_system
436
+
437
+
let pp_state ppf = function
438
+
| Cartesian c ->
439
+
Fmt.pf ppf "Cartesian: (%.6f, %.6f, %.6f) km (%.9f, %.9f, %.9f) km/s" c.x
440
+
c.y c.z c.x_dot c.y_dot c.z_dot
441
+
| Keplerian ke ->
442
+
Fmt.pf ppf "Keplerian: a=%.3f km e=%.6f i=%.3f deg" ke.semi_major_axis
443
+
ke.eccentricity ke.inclination
444
+
445
+
let pp ppf opm =
446
+
Fmt.pf ppf "@[<v>%a@,%a@,%a: %a@]" pp_header opm.header pp_metadata
447
+
opm.metadata (Ptime.pp_rfc3339 ()) opm.epoch pp_state opm.state
+149
lib/opm.mli
+149
lib/opm.mli
···
1
+
(** CCSDS 502.0-B Orbit Parameter Message (OPM) parser and serializer.
2
+
3
+
Parses the KVN (Keyword=Value Notation) text format for orbit parameter
4
+
data. Supports Cartesian state vectors and Keplerian orbital elements, with
5
+
optional spacecraft parameters and maneuver definitions.
6
+
7
+
Reference: {{:https://public.ccsds.org/Pubs/502x0b3e1.pdf} CCSDS 502.0-B-3}
8
+
Orbit Data Messages, Annex (OPM). *)
9
+
10
+
(** {1 Types} *)
11
+
12
+
type keplerian = {
13
+
semi_major_axis : float; (** km *)
14
+
eccentricity : float;
15
+
inclination : float; (** deg *)
16
+
ra_of_asc_node : float; (** deg *)
17
+
arg_of_pericenter : float; (** deg *)
18
+
true_anomaly : float option; (** deg *)
19
+
mean_anomaly : float option; (** deg *)
20
+
gm : float option; (** km^3/s^2 *)
21
+
}
22
+
(** Keplerian orbital elements. *)
23
+
24
+
type spacecraft_parameters = {
25
+
mass : float option; (** kg *)
26
+
solar_rad_area : float option; (** m^2 *)
27
+
solar_rad_coeff : float option;
28
+
drag_area : float option; (** m^2 *)
29
+
drag_coeff : float option;
30
+
}
31
+
(** Optional spacecraft physical parameters. *)
32
+
33
+
type cartesian = {
34
+
epoch : Ptime.t;
35
+
x : float;
36
+
y : float;
37
+
z : float; (** km *)
38
+
x_dot : float;
39
+
y_dot : float;
40
+
z_dot : float; (** km/s *)
41
+
}
42
+
(** Cartesian state vector at an epoch. *)
43
+
44
+
type state =
45
+
| Cartesian of cartesian
46
+
| Keplerian of keplerian (** Orbit state: either Cartesian or Keplerian. *)
47
+
48
+
type maneuver = {
49
+
man_epoch_ignition : Ptime.t;
50
+
man_duration : float; (** s *)
51
+
man_delta_mass : float; (** kg *)
52
+
man_ref_frame : string;
53
+
man_dv_1 : float; (** km/s *)
54
+
man_dv_2 : float; (** km/s *)
55
+
man_dv_3 : float; (** km/s *)
56
+
}
57
+
(** A single maneuver definition. *)
58
+
59
+
type covariance = {
60
+
cov_ref_frame : string option;
61
+
cx_x : float;
62
+
cy_x : float;
63
+
cy_y : float;
64
+
cz_x : float;
65
+
cz_y : float;
66
+
cz_z : float;
67
+
cx_dot_x : float;
68
+
cx_dot_y : float;
69
+
cx_dot_z : float;
70
+
cx_dot_x_dot : float;
71
+
cy_dot_x : float;
72
+
cy_dot_y : float;
73
+
cy_dot_z : float;
74
+
cy_dot_x_dot : float;
75
+
cy_dot_y_dot : float;
76
+
cz_dot_x : float;
77
+
cz_dot_y : float;
78
+
cz_dot_z : float;
79
+
cz_dot_x_dot : float;
80
+
cz_dot_y_dot : float;
81
+
cz_dot_z_dot : float;
82
+
}
83
+
(** Position/velocity covariance matrix (upper triangle, 6x6 = 21 elements). *)
84
+
85
+
type metadata = {
86
+
object_name : string;
87
+
object_id : string;
88
+
center_name : string;
89
+
ref_frame : string;
90
+
time_system : string;
91
+
}
92
+
(** OPM metadata. *)
93
+
94
+
type header = { version : string; creation_date : string; originator : string }
95
+
(** OPM file header. *)
96
+
97
+
type t = {
98
+
header : header;
99
+
metadata : metadata;
100
+
epoch : Ptime.t;
101
+
state : state;
102
+
spacecraft : spacecraft_parameters option;
103
+
covariance : covariance option;
104
+
maneuvers : maneuver list;
105
+
}
106
+
(** A complete OPM message. *)
107
+
108
+
(** {1 Errors} *)
109
+
110
+
type error =
111
+
| Unexpected_eof
112
+
| Bad_keyword of { line : int; got : string }
113
+
| Bad_epoch of { line : int; value : string }
114
+
| Bad_float of { line : int; value : string }
115
+
| Missing_keyword of string
116
+
| Parse_error of string
117
+
118
+
val pp_error : error Fmt.t
119
+
(** [pp_error] pretty-prints a parse error. *)
120
+
121
+
(** {1 Parsing} *)
122
+
123
+
val of_string : string -> (t, error) result
124
+
(** [of_string s] parses an OPM message from a KVN string. *)
125
+
126
+
val of_channel : in_channel -> (t, error) result
127
+
(** [of_channel ic] parses an OPM message from an input channel. *)
128
+
129
+
val of_file : string -> (t, error) result
130
+
(** [of_file path] parses an OPM message from a file path. *)
131
+
132
+
(** {1 Serialization} *)
133
+
134
+
val to_string : t -> string
135
+
(** [to_string opm] serializes an OPM message to KVN format. *)
136
+
137
+
(** {1 Pretty-printing} *)
138
+
139
+
val pp_header : header Fmt.t
140
+
(** [pp_header] pretty-prints an OPM header. *)
141
+
142
+
val pp_metadata : metadata Fmt.t
143
+
(** [pp_metadata] pretty-prints OPM metadata. *)
144
+
145
+
val pp_state : state Fmt.t
146
+
(** [pp_state] pretty-prints an orbit state. *)
147
+
148
+
val pp : t Fmt.t
149
+
(** [pp] pretty-prints an OPM message summary. *)
+2
-1
odm.opam
+2
-1
odm.opam
···
2
2
opam-version: "2.0"
3
3
synopsis: "Orbit Data Messages (CCSDS 502.0-B-3)"
4
4
description:
5
-
"Parse and manipulate Orbit Data Messages for satellite ephemeris exchange. Supports CCSDS 502.0-B-3 OEM (Orbit Ephemeris Message) KVN format with multi-segment and acceleration data."
5
+
"Parse and manipulate Orbit Data Messages (CCSDS 502.0-B-3) for satellite ephemeris exchange. Includes OEM (Orbit Ephemeris Message) and OPM (Orbit Parameter Message) KVN format parsers."
6
6
maintainer: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
7
7
authors: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
8
8
license: "ISC"
···
11
11
depends: [
12
12
"dune" {>= "3.21"}
13
13
"ocaml" {>= "4.14"}
14
+
"kvn"
14
15
"ptime"
15
16
"fmt"
16
17
"alcotest" {with-test}
+2
-1
test/test.ml
+2
-1
test/test.ml
+185
test/test_opm.ml
+185
test/test_opm.ml
···
1
+
(** OPM parsing and serialization tests.
2
+
3
+
Test vectors from CCSDS 502.0-B-3 Annex (OPM normative example). *)
4
+
5
+
let eps = 1e-6
6
+
7
+
let check_float msg expected actual =
8
+
Alcotest.(check (float eps)) msg expected actual
9
+
10
+
let check_ok msg = function
11
+
| Ok v -> v
12
+
| Error e -> Alcotest.failf "%s: %a" msg Odm.Opm.pp_error e
13
+
14
+
(* ------------------------------------------------------------------ *)
15
+
(* CCSDS Blue Book example — Cartesian state vector *)
16
+
(* ------------------------------------------------------------------ *)
17
+
18
+
let ccsds_cartesian =
19
+
{|CCSDS_OPM_VERS = 2.0
20
+
CREATION_DATE = 2004-281T17:17:08
21
+
ORIGINATOR = NASA/JPL
22
+
COMMENT this is an example
23
+
OBJECT_NAME = MARS GLOBAL SURVEYOR
24
+
OBJECT_ID = 2001-025A
25
+
CENTER_NAME = MARS BARYCENTER
26
+
REF_FRAME = EME2000
27
+
TIME_SYSTEM = UTC
28
+
EPOCH = 2004-100T00:00:00.000
29
+
X = 4867.946816 [km]
30
+
Y = -3175.839452 [km]
31
+
Z = 2817.207577 [km]
32
+
X_DOT = 3.983900621 [km/s]
33
+
Y_DOT = 5.765476583 [km/s]
34
+
Z_DOT = 1.876698998 [km/s]
35
+
|}
36
+
37
+
let test_parse_cartesian () =
38
+
let opm = check_ok "parse" (Odm.Opm.of_string ccsds_cartesian) in
39
+
Alcotest.(check string) "version" "2.0" opm.header.version;
40
+
Alcotest.(check string) "originator" "NASA/JPL" opm.header.originator;
41
+
Alcotest.(check string) "name" "MARS GLOBAL SURVEYOR" opm.metadata.object_name;
42
+
Alcotest.(check string) "id" "2001-025A" opm.metadata.object_id;
43
+
Alcotest.(check string) "center" "MARS BARYCENTER" opm.metadata.center_name;
44
+
Alcotest.(check string) "frame" "EME2000" opm.metadata.ref_frame;
45
+
match opm.state with
46
+
| Odm.Opm.Keplerian _ -> Alcotest.fail "expected Cartesian"
47
+
| Odm.Opm.Cartesian c ->
48
+
check_float "x" 4867.946816 c.x;
49
+
check_float "y" (-3175.839452) c.y;
50
+
check_float "z" 2817.207577 c.z;
51
+
check_float "x_dot" 3.983900621 c.x_dot;
52
+
check_float "y_dot" 5.765476583 c.y_dot;
53
+
check_float "z_dot" 1.876698998 c.z_dot
54
+
55
+
(* ------------------------------------------------------------------ *)
56
+
(* Keplerian elements *)
57
+
(* ------------------------------------------------------------------ *)
58
+
59
+
let keplerian_example =
60
+
{|CCSDS_OPM_VERS = 2.0
61
+
CREATION_DATE = 2025-01-15T00:00:00
62
+
ORIGINATOR = TEST
63
+
OBJECT_NAME = ISS (ZARYA)
64
+
OBJECT_ID = 1998-067A
65
+
CENTER_NAME = EARTH
66
+
REF_FRAME = EME2000
67
+
TIME_SYSTEM = UTC
68
+
EPOCH = 2025-01-15T00:00:00.000
69
+
SEMI_MAJOR_AXIS = 6794.137 [km]
70
+
ECCENTRICITY = 0.0006703
71
+
INCLINATION = 51.6437 [deg]
72
+
RA_OF_ASC_NODE = 247.2506 [deg]
73
+
ARG_OF_PERICENTER = 130.5360 [deg]
74
+
TRUE_ANOMALY = 325.1210 [deg]
75
+
GM = 398600.4418 [km**3/s**2]
76
+
|}
77
+
78
+
let test_parse_keplerian () =
79
+
let opm = check_ok "parse" (Odm.Opm.of_string keplerian_example) in
80
+
Alcotest.(check string) "name" "ISS (ZARYA)" opm.metadata.object_name;
81
+
match opm.state with
82
+
| Odm.Opm.Cartesian _ -> Alcotest.fail "expected Keplerian"
83
+
| Odm.Opm.Keplerian ke ->
84
+
check_float "sma" 6794.137 ke.semi_major_axis;
85
+
check_float "ecc" 0.0006703 ke.eccentricity;
86
+
check_float "inc" 51.6437 ke.inclination;
87
+
check_float "raan" 247.2506 ke.ra_of_asc_node;
88
+
check_float "aop" 130.5360 ke.arg_of_pericenter;
89
+
check_float "ta" 325.1210 (Option.get ke.true_anomaly);
90
+
check_float "gm" 398600.4418 (Option.get ke.gm)
91
+
92
+
(* ------------------------------------------------------------------ *)
93
+
(* Maneuvers *)
94
+
(* ------------------------------------------------------------------ *)
95
+
96
+
let maneuver_example =
97
+
{|CCSDS_OPM_VERS = 2.0
98
+
CREATION_DATE = 2025-01-15T00:00:00
99
+
ORIGINATOR = ESA
100
+
OBJECT_NAME = SENTINEL-1A
101
+
OBJECT_ID = 2014-016A
102
+
CENTER_NAME = EARTH
103
+
REF_FRAME = EME2000
104
+
TIME_SYSTEM = UTC
105
+
EPOCH = 2025-01-15T00:00:00.000
106
+
X = 7000.0 [km]
107
+
Y = 0.0 [km]
108
+
Z = 0.0 [km]
109
+
X_DOT = 0.0 [km/s]
110
+
Y_DOT = 7.546 [km/s]
111
+
Z_DOT = 0.0 [km/s]
112
+
MAN_EPOCH_IGNITION = 2025-01-15T06:00:00.000
113
+
MAN_DURATION = 120.0 [s]
114
+
MAN_DELTA_MASS = -0.5 [kg]
115
+
MAN_REF_FRAME = TNW
116
+
MAN_DV_1 = 0.001 [km/s]
117
+
MAN_DV_2 = 0.0 [km/s]
118
+
MAN_DV_3 = 0.0 [km/s]
119
+
MAN_EPOCH_IGNITION = 2025-01-15T12:00:00.000
120
+
MAN_DURATION = 60.0 [s]
121
+
MAN_DELTA_MASS = -0.25 [kg]
122
+
MAN_REF_FRAME = TNW
123
+
MAN_DV_1 = 0.0005 [km/s]
124
+
MAN_DV_2 = 0.0 [km/s]
125
+
MAN_DV_3 = 0.0 [km/s]
126
+
|}
127
+
128
+
let test_parse_maneuvers () =
129
+
let opm = check_ok "parse" (Odm.Opm.of_string maneuver_example) in
130
+
Alcotest.(check int) "maneuver count" 2 (List.length opm.maneuvers);
131
+
let m1 = List.nth opm.maneuvers 0 in
132
+
check_float "man1 duration" 120.0 m1.man_duration;
133
+
check_float "man1 dv_1" 0.001 m1.man_dv_1;
134
+
Alcotest.(check string) "man1 frame" "TNW" m1.man_ref_frame;
135
+
let m2 = List.nth opm.maneuvers 1 in
136
+
check_float "man2 duration" 60.0 m2.man_duration;
137
+
check_float "man2 dv_1" 0.0005 m2.man_dv_1
138
+
139
+
(* ------------------------------------------------------------------ *)
140
+
(* Roundtrip *)
141
+
(* ------------------------------------------------------------------ *)
142
+
143
+
let test_roundtrip_cartesian () =
144
+
let opm = check_ok "parse1" (Odm.Opm.of_string ccsds_cartesian) in
145
+
let kvn = Odm.Opm.to_string opm in
146
+
let opm2 = check_ok "parse2" (Odm.Opm.of_string kvn) in
147
+
Alcotest.(check string)
148
+
"name" opm.metadata.object_name opm2.metadata.object_name;
149
+
Alcotest.(check string) "id" opm.metadata.object_id opm2.metadata.object_id;
150
+
match (opm.state, opm2.state) with
151
+
| Odm.Opm.Cartesian c1, Odm.Opm.Cartesian c2 ->
152
+
check_float "x" c1.x c2.x;
153
+
check_float "y" c1.y c2.y;
154
+
check_float "z" c1.z c2.z;
155
+
check_float "x_dot" c1.x_dot c2.x_dot;
156
+
check_float "y_dot" c1.y_dot c2.y_dot;
157
+
check_float "z_dot" c1.z_dot c2.z_dot
158
+
| _ -> Alcotest.fail "state type mismatch on roundtrip"
159
+
160
+
let test_roundtrip_keplerian () =
161
+
let opm = check_ok "parse1" (Odm.Opm.of_string keplerian_example) in
162
+
let kvn = Odm.Opm.to_string opm in
163
+
let opm2 = check_ok "parse2" (Odm.Opm.of_string kvn) in
164
+
match (opm.state, opm2.state) with
165
+
| Odm.Opm.Keplerian k1, Odm.Opm.Keplerian k2 ->
166
+
check_float "sma" k1.semi_major_axis k2.semi_major_axis;
167
+
check_float "ecc" k1.eccentricity k2.eccentricity;
168
+
check_float "inc" k1.inclination k2.inclination
169
+
| _ -> Alcotest.fail "state type mismatch on roundtrip"
170
+
171
+
let test_empty () =
172
+
let opm = check_ok "empty" (Odm.Opm.of_string "") in
173
+
Alcotest.(check string) "version" "" opm.header.version;
174
+
Alcotest.(check int) "no maneuvers" 0 (List.length opm.maneuvers)
175
+
176
+
let suite =
177
+
( "opm",
178
+
[
179
+
Alcotest.test_case "parse Cartesian" `Quick test_parse_cartesian;
180
+
Alcotest.test_case "parse Keplerian" `Quick test_parse_keplerian;
181
+
Alcotest.test_case "parse maneuvers" `Quick test_parse_maneuvers;
182
+
Alcotest.test_case "roundtrip Cartesian" `Quick test_roundtrip_cartesian;
183
+
Alcotest.test_case "roundtrip Keplerian" `Quick test_roundtrip_keplerian;
184
+
Alcotest.test_case "empty" `Quick test_empty;
185
+
] )