CCSDS 504.0-B Attitude Ephemeris Message parser and serializer
Add 8 new CCSDS/RFC protocol packages
- ocaml-rice: CCSDS 121.0-B lossless compression (Rice/Golomb)
- ocaml-udpcl: RFC 7122 UDP convergence layer for Bundle Protocol
- ocaml-erasure: CCSDS 131.5-B erasure correcting codes (GF(2^8))
- ocaml-short-ldpc: CCSDS 131.4-B short block-length LDPC
- ocaml-opm: CCSDS 502.0-B Orbit Parameter Message (KVN)
- ocaml-aem: CCSDS 504.0-B Attitude Ephemeris Message (KVN)
- ocaml-tdm: CCSDS 503.0-B Tracking Data Message (KVN)
- ocaml-rdm: CCSDS 508.1-B Re-entry Data Message (KVN)
+749
+41
README.md
+41
README.md
···
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# aem
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CCSDS 504.0-B Attitude Ephemeris Message parser and serializer.
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Parses the KVN (Keyword=Value Notation) text format for attitude ephemeris
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data. Supports quaternion (scalar-last) and Euler angle attitude representations,
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with time-tagged attitude data points organized in segments.
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Reference: [CCSDS 504.0-B-2](https://public.ccsds.org/Pubs/504x0b2.pdf)
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Attitude Data Messages.
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## Installation
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```
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opam install aem
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```
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## Usage
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```ocaml
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match Aem.of_string kvn_text with
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| Ok aem ->
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Printf.printf "Object: %s\n" (List.hd aem.segments).metadata.object_name;
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let seg = List.hd aem.segments in
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let att = seg.data.(0) in
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Printf.printf "Quaternion: (%.6f, %.6f, %.6f, %.6f)\n"
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att.q1 att.q2 att.q3 att.qc
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| Error e -> Fmt.epr "%a\n" Aem.pp_error e
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```
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## API Overview
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- **`type t`** -- Complete AEM file: header + segment list
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- **`type segment`** -- Metadata + array of attitude data points
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- **`type attitude_data`** -- Epoch + quaternion or Euler angles
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- **`of_string`**, **`of_channel`**, **`of_file`** -- Parse KVN format
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- **`to_string`** -- Serialize back to KVN format
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## License
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ISC
+32
aem.opam
+32
aem.opam
···
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# This file is generated by dune, edit dune-project instead
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opam-version: "2.0"
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synopsis: "CCSDS 504.0-B Attitude Ephemeris Message parser and serializer"
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maintainer: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
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authors: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
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license: "ISC"
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homepage: "https://tangled.org/gazagnaire.org/ocaml-aem"
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bug-reports: "https://tangled.org/gazagnaire.org/ocaml-aem/issues"
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depends: [
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"dune" {>= "3.21"}
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"ocaml" {>= "4.14"}
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"kvn"
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"fmt"
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"ptime"
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"odoc" {with-doc}
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]
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build: [
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["dune" "subst"] {dev}
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[
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"dune"
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"build"
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"-p"
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name
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"-j"
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jobs
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"@install"
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"@runtest" {with-test}
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"@doc" {with-doc}
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]
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]
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dev-repo: "git+https://tangled.org/gazagnaire.org/ocaml-aem"
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x-maintenance-intent: ["(latest)"]
+19
dune-project
+19
dune-project
···
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(lang dune 3.21)
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(name aem)
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(source (tangled gazagnaire.org/ocaml-aem))
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(formatting (enabled_for ocaml))
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(generate_opam_files true)
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(license ISC)
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(authors "Thomas Gazagnaire <thomas@gazagnaire.org>")
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(maintainers "Thomas Gazagnaire <thomas@gazagnaire.org>")
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(package
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(name aem)
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(synopsis "CCSDS 504.0-B Attitude Ephemeris Message parser and serializer")
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(depends
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(ocaml (>= 4.14))
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kvn
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fmt
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ptime))
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lib/aem.ml
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lib/aem.ml
···
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(*---------------------------------------------------------------------------
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Copyright (c) 2025 Thomas Gazagnaire. All rights reserved.
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SPDX-License-Identifier: ISC
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---------------------------------------------------------------------------*)
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(** CCSDS 504.0-B Attitude Ephemeris Message (AEM) parser and serializer. *)
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(* ------------------------------------------------------------------ *)
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(* Types *)
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(* ------------------------------------------------------------------ *)
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type quaternion = { q1 : float; q2 : float; q3 : float; qc : float }
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type euler_angles = { angle_1 : float; angle_2 : float; angle_3 : float }
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type attitude = Quaternion of quaternion | Euler of euler_angles
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type attitude_data = { epoch : Ptime.t; attitude : attitude }
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type metadata = {
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object_name : string;
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object_id : string;
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center_name : string;
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ref_frame_a : string;
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ref_frame_b : string;
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attitude_dir : string;
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time_system : string;
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start_time : Ptime.t;
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stop_time : Ptime.t;
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attitude_type : string;
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interpolation_method : string option;
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interpolation_degree : int option;
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}
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type segment = { metadata : metadata; data : attitude_data array }
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type header = { version : string; creation_date : string; originator : string }
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type t = { header : header; segments : segment list }
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type error =
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| Unexpected_eof
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| Bad_keyword of { line : int; got : string }
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| Bad_epoch of { line : int; value : string }
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| Bad_float of { line : int; value : string }
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| Missing_keyword of string
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| Parse_error of string
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let pp_error ppf = function
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| Unexpected_eof -> Fmt.pf ppf "Unexpected end of file"
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| Bad_keyword { line; got } -> Fmt.pf ppf "Line %d: bad keyword %S" line got
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| Bad_epoch { line; value } -> Fmt.pf ppf "Line %d: bad epoch %S" line value
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| Bad_float { line; value } -> Fmt.pf ppf "Line %d: bad float %S" line value
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| Missing_keyword kw -> Fmt.pf ppf "Missing required keyword %S" kw
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| Parse_error msg -> Fmt.pf ppf "Parse error: %s" msg
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(* ------------------------------------------------------------------ *)
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(* KVN parsing *)
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(* ------------------------------------------------------------------ *)
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let parse_epoch = Kvn.parse_epoch
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let parse_header st =
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Kvn.skip_blanks st;
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let version = ref "" in
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let creation_date = ref "" in
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let originator = ref "" in
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let cont = ref true in
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while !cont do
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match Kvn.peek st with
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| Some (_, s) -> (
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match Kvn.classify s with
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| Kvn.Keyword ("CCSDS_AEM_VERS", v) ->
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version := v;
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Kvn.advance st
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| Kvn.Keyword ("CREATION_DATE", v) ->
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creation_date := v;
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Kvn.advance st
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| Kvn.Keyword ("ORIGINATOR", v) ->
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originator := v;
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Kvn.advance st
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| Kvn.Comment _ -> Kvn.advance st
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| Kvn.Blank -> Kvn.advance st
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| _ -> cont := false)
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| None -> cont := false
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done;
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{
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version = !version;
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creation_date = !creation_date;
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originator = !originator;
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}
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type meta_acc = {
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mutable m_object_name : string;
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mutable m_object_id : string;
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mutable m_center_name : string;
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mutable m_ref_frame_a : string;
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mutable m_ref_frame_b : string;
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mutable m_attitude_dir : string;
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mutable m_time_system : string;
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mutable m_start_time : Ptime.t;
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mutable m_stop_time : Ptime.t;
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mutable m_attitude_type : string;
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mutable m_interpolation_method : string option;
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mutable m_interpolation_degree : int option;
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}
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let set_meta_field acc key value =
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match key with
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| "OBJECT_NAME" -> acc.m_object_name <- value
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| "OBJECT_ID" -> acc.m_object_id <- value
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| "CENTER_NAME" -> acc.m_center_name <- value
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| "REF_FRAME_A" -> acc.m_ref_frame_a <- value
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| "REF_FRAME_B" -> acc.m_ref_frame_b <- value
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| "ATTITUDE_DIR" -> acc.m_attitude_dir <- value
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| "TIME_SYSTEM" -> acc.m_time_system <- value
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| "START_TIME" -> (
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match parse_epoch value with
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| Some t -> acc.m_start_time <- t
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| None -> ())
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| "STOP_TIME" -> (
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match parse_epoch value with Some t -> acc.m_stop_time <- t | None -> ())
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| "ATTITUDE_TYPE" -> acc.m_attitude_type <- value
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| "INTERPOLATION_METHOD" -> acc.m_interpolation_method <- Some value
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| "INTERPOLATION_DEGREE" ->
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acc.m_interpolation_degree <-
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(match int_of_string_opt value with Some i -> Some i | None -> None)
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| _ -> ()
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let meta_acc_to_metadata acc =
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{
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object_name = acc.m_object_name;
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object_id = acc.m_object_id;
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center_name = acc.m_center_name;
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ref_frame_a = acc.m_ref_frame_a;
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ref_frame_b = acc.m_ref_frame_b;
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attitude_dir = acc.m_attitude_dir;
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time_system = acc.m_time_system;
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start_time = acc.m_start_time;
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stop_time = acc.m_stop_time;
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attitude_type = acc.m_attitude_type;
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interpolation_method = acc.m_interpolation_method;
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interpolation_degree = acc.m_interpolation_degree;
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}
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let parse_metadata st =
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Kvn.skip_blanks st;
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(match Kvn.next st with
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| Some (_, s) when String.trim s = "META_START" -> ()
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| _ -> ());
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let acc =
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{
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m_object_name = "";
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m_object_id = "";
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m_center_name = "EARTH";
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m_ref_frame_a = "";
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m_ref_frame_b = "";
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m_attitude_dir = "A2B";
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m_time_system = "UTC";
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m_start_time = Ptime.epoch;
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m_stop_time = Ptime.epoch;
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m_attitude_type = "QUATERNION";
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m_interpolation_method = None;
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m_interpolation_degree = None;
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}
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in
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let cont = ref true in
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while !cont do
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match Kvn.peek st with
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| Some (_, s) -> (
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match Kvn.classify s with
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| Kvn.Keyword ("META_STOP", _) ->
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Kvn.advance st;
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cont := false
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| Kvn.Comment _ -> Kvn.advance st
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| Kvn.Keyword (k, v) ->
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set_meta_field acc k v;
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Kvn.advance st
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| Kvn.Blank -> Kvn.advance st
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| Kvn.Data _ -> cont := false)
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| None -> cont := false
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done;
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meta_acc_to_metadata acc
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+
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let is_euler att_type =
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let s = String.uppercase_ascii att_type in
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s = "EULER_ANGLE" || s = "EULER_ANGLES" || s = "EULER"
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+
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let parse_data st att_type =
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Kvn.skip_blanks st;
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let points = ref [] in
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let cont = ref true in
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while !cont do
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match Kvn.peek st with
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| Some (_, s) -> (
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let trimmed = String.trim s in
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if trimmed = "META_START" || trimmed = "" then cont := false
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else
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match Kvn.classify s with
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| Kvn.Keyword _ -> cont := false
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| Kvn.Blank -> Kvn.advance st
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| Kvn.Comment _ -> Kvn.advance st
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+
| Kvn.Data d -> (
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let parts = Kvn.split_data d in
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match parts with
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| epoch_s :: rest when List.length rest >= 4 -> (
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match parse_epoch epoch_s with
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| Some epoch ->
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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
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| Some f -> f
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| None -> 0.)
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rest
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+
in
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let a = Array.of_list floats in
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let attitude =
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if is_euler att_type then
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Euler
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{
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angle_1 = a.(0);
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angle_2 = a.(1);
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angle_3 = a.(2);
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}
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else
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Quaternion
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{ q1 = a.(0); q2 = a.(1); q3 = a.(2); qc = a.(3) }
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in
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points := { epoch; attitude } :: !points;
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Kvn.advance st
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| None -> Kvn.advance st)
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| _ -> Kvn.advance st))
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| None -> cont := false
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done;
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Array.of_list (List.rev !points)
232
+
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let parse_segment st =
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let metadata = parse_metadata st in
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let data = parse_data st metadata.attitude_type in
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{ metadata; data }
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+
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let parse st =
239
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let header = parse_header st in
240
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let segments = ref [] in
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let cont = ref true in
242
+
while !cont do
243
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Kvn.skip_blanks st;
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match Kvn.peek st with
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| Some (_, s) when String.trim s = "META_START" ->
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let seg = parse_segment st in
247
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segments := seg :: !segments
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| Some _ -> Kvn.advance st
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| None -> cont := false
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done;
251
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Ok { header; segments = List.rev !segments }
252
+
253
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let of_string s =
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let st = Kvn.of_string s in
255
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parse st
256
+
257
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let of_channel ic =
258
+
let st = Kvn.of_channel ic in
259
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parse st
260
+
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let of_file path =
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let ic = open_in path in
263
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let r = of_channel ic in
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close_in ic;
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r
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+
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(* ------------------------------------------------------------------ *)
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(* Serialization *)
269
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(* ------------------------------------------------------------------ *)
270
+
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let fmt_epoch buf t =
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let (y, m, d), ((hh, mm, ss), _tz) = Ptime.to_date_time t in
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let frac = Ptime.to_float_s t -. floor (Ptime.to_float_s t) in
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Printf.bprintf buf "%04d-%02d-%02dT%02d:%02d:%06.3f" y m d hh mm
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(Float.of_int ss +. frac)
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+
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let kv buf k v = Printf.bprintf buf "%s = %s\n" k v
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+
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let to_string aem =
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let buf = Buffer.create 2048 in
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kv buf "CCSDS_AEM_VERS" aem.header.version;
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+
kv buf "CREATION_DATE" aem.header.creation_date;
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+
kv buf "ORIGINATOR" aem.header.originator;
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List.iter
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(fun seg ->
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Buffer.add_char buf '\n';
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Buffer.add_string buf "META_START\n";
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kv buf "OBJECT_NAME" seg.metadata.object_name;
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kv buf "OBJECT_ID" seg.metadata.object_id;
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+
kv buf "CENTER_NAME" seg.metadata.center_name;
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+
kv buf "REF_FRAME_A" seg.metadata.ref_frame_a;
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+
kv buf "REF_FRAME_B" seg.metadata.ref_frame_b;
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+
kv buf "ATTITUDE_DIR" seg.metadata.attitude_dir;
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+
kv buf "TIME_SYSTEM" seg.metadata.time_system;
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+
Printf.bprintf buf "START_TIME = ";
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+
fmt_epoch buf seg.metadata.start_time;
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+
Buffer.add_char buf '\n';
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+
Printf.bprintf buf "STOP_TIME = ";
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+
fmt_epoch buf seg.metadata.stop_time;
300
+
Buffer.add_char buf '\n';
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+
kv buf "ATTITUDE_TYPE" seg.metadata.attitude_type;
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(match seg.metadata.interpolation_method with
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| Some m -> kv buf "INTERPOLATION_METHOD" m
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+
| None -> ());
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+
(match seg.metadata.interpolation_degree with
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+
| Some d -> kv buf "INTERPOLATION_DEGREE" (string_of_int d)
307
+
| None -> ());
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+
Buffer.add_string buf "META_STOP\n";
309
+
Buffer.add_char buf '\n';
310
+
Array.iter
311
+
(fun (ad : attitude_data) ->
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+
fmt_epoch buf ad.epoch;
313
+
(match ad.attitude with
314
+
| Quaternion q ->
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+
Printf.bprintf buf " %.14g %.14g %.14g %.14g" q.q1 q.q2 q.q3 q.qc
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+
| Euler e ->
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+
Printf.bprintf buf " %.14g %.14g %.14g" e.angle_1 e.angle_2
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+
e.angle_3);
319
+
Buffer.add_char buf '\n')
320
+
seg.data)
321
+
aem.segments;
322
+
Buffer.contents buf
323
+
324
+
(* ------------------------------------------------------------------ *)
325
+
(* Pretty-printing *)
326
+
(* ------------------------------------------------------------------ *)
327
+
328
+
let pp_header ppf h =
329
+
Fmt.pf ppf "AEM v%s by %s (%s)" h.version h.originator h.creation_date
330
+
331
+
let pp_metadata ppf m =
332
+
Fmt.pf ppf "%s [%s] %s %s->%s %s %a-%a" m.object_name m.object_id
333
+
m.attitude_type m.ref_frame_a m.ref_frame_b m.time_system
334
+
(Ptime.pp_rfc3339 ()) m.start_time (Ptime.pp_rfc3339 ()) m.stop_time
335
+
336
+
let pp_attitude_data ppf ad =
337
+
match ad.attitude with
338
+
| Quaternion q ->
339
+
Fmt.pf ppf "%a q=(%.6f, %.6f, %.6f, %.6f)" (Ptime.pp_rfc3339 ()) ad.epoch
340
+
q.q1 q.q2 q.q3 q.qc
341
+
| Euler e ->
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+
Fmt.pf ppf "%a euler=(%.3f, %.3f, %.3f)" (Ptime.pp_rfc3339 ()) ad.epoch
343
+
e.angle_1 e.angle_2 e.angle_3
344
+
345
+
let pp ppf aem =
346
+
Fmt.pf ppf "@[<v>%a (%d segments)@," pp_header aem.header
347
+
(List.length aem.segments);
348
+
List.iter
349
+
(fun seg ->
350
+
Fmt.pf ppf " %a (%d points)@," pp_metadata seg.metadata
351
+
(Array.length seg.data))
352
+
aem.segments
+101
lib/aem.mli
+101
lib/aem.mli
···
1
+
(** CCSDS 504.0-B Attitude Ephemeris Message (AEM) parser and serializer.
2
+
3
+
Parses the KVN (Keyword=Value Notation) text format for attitude ephemeris
4
+
data. Supports quaternion (scalar-last QC convention) and Euler angle
5
+
representations with time-tagged data points.
6
+
7
+
Reference: {{:https://public.ccsds.org/Pubs/504x0b2.pdf} CCSDS 504.0-B-2}
8
+
Attitude Data Messages. *)
9
+
10
+
(** {1 Types} *)
11
+
12
+
type quaternion = {
13
+
q1 : float; (** Vector component 1. *)
14
+
q2 : float; (** Vector component 2. *)
15
+
q3 : float; (** Vector component 3. *)
16
+
qc : float; (** Scalar component. *)
17
+
}
18
+
(** Attitude quaternion (scalar-last convention per CCSDS). *)
19
+
20
+
type euler_angles = {
21
+
angle_1 : float; (** First rotation angle, deg. *)
22
+
angle_2 : float; (** Second rotation angle, deg. *)
23
+
angle_3 : float; (** Third rotation angle, deg. *)
24
+
}
25
+
(** Euler angle attitude representation. *)
26
+
27
+
type attitude =
28
+
| Quaternion of quaternion
29
+
| Euler of euler_angles
30
+
(** Attitude representation: quaternion or Euler angles. *)
31
+
32
+
type attitude_data = { epoch : Ptime.t; attitude : attitude }
33
+
(** A single time-tagged attitude data point. *)
34
+
35
+
type metadata = {
36
+
object_name : string;
37
+
object_id : string;
38
+
center_name : string;
39
+
ref_frame_a : string;
40
+
ref_frame_b : string;
41
+
attitude_dir : string;
42
+
time_system : string;
43
+
start_time : Ptime.t;
44
+
stop_time : Ptime.t;
45
+
attitude_type : string;
46
+
interpolation_method : string option;
47
+
interpolation_degree : int option;
48
+
}
49
+
(** Metadata block describing an attitude segment. *)
50
+
51
+
type segment = { metadata : metadata; data : attitude_data array }
52
+
(** One attitude segment (metadata + data). *)
53
+
54
+
type header = { version : string; creation_date : string; originator : string }
55
+
(** AEM file header. *)
56
+
57
+
type t = { header : header; segments : segment list }
58
+
(** A complete AEM file with header and one or more segments. *)
59
+
60
+
(** {1 Errors} *)
61
+
62
+
type error =
63
+
| Unexpected_eof
64
+
| Bad_keyword of { line : int; got : string }
65
+
| Bad_epoch of { line : int; value : string }
66
+
| Bad_float of { line : int; value : string }
67
+
| Missing_keyword of string
68
+
| Parse_error of string
69
+
70
+
val pp_error : error Fmt.t
71
+
(** [pp_error] pretty-prints a parse error. *)
72
+
73
+
(** {1 Parsing} *)
74
+
75
+
val of_string : string -> (t, error) result
76
+
(** [of_string s] parses an AEM file from a KVN string. *)
77
+
78
+
val of_channel : in_channel -> (t, error) result
79
+
(** [of_channel ic] parses an AEM file from an input channel. *)
80
+
81
+
val of_file : string -> (t, error) result
82
+
(** [of_file path] parses an AEM file from a file path. *)
83
+
84
+
(** {1 Serialization} *)
85
+
86
+
val to_string : t -> string
87
+
(** [to_string aem] serializes an AEM file to KVN format. *)
88
+
89
+
(** {1 Pretty-printing} *)
90
+
91
+
val pp_header : header Fmt.t
92
+
(** [pp_header] pretty-prints an AEM header. *)
93
+
94
+
val pp_metadata : metadata Fmt.t
95
+
(** [pp_metadata] pretty-prints segment metadata. *)
96
+
97
+
val pp_attitude_data : attitude_data Fmt.t
98
+
(** [pp_attitude_data] pretty-prints a single attitude data point. *)
99
+
100
+
val pp : t Fmt.t
101
+
(** [pp] pretty-prints an AEM file summary. *)
+1
test/test.ml
+1
test/test.ml
···
1
+
let () = Alcotest.run "aem" [ Test_aem.suite ]
+194
test/test_aem.ml
+194
test/test_aem.ml
···
1
+
(** AEM parsing and serialization tests.
2
+
3
+
Test vectors from CCSDS 504.0-B-2 examples. *)
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 Aem.pp_error e
13
+
14
+
(* ------------------------------------------------------------------ *)
15
+
(* CCSDS-style quaternion example *)
16
+
(* ------------------------------------------------------------------ *)
17
+
18
+
let quaternion_example =
19
+
{|CCSDS_AEM_VERS = 1.0
20
+
CREATION_DATE = 2025-01-15T00:00:00
21
+
ORIGINATOR = NASA/GSFC
22
+
23
+
META_START
24
+
OBJECT_NAME = AURA
25
+
OBJECT_ID = 2004-026A
26
+
CENTER_NAME = EARTH
27
+
REF_FRAME_A = EME2000
28
+
REF_FRAME_B = SC_BODY_1
29
+
ATTITUDE_DIR = A2B
30
+
TIME_SYSTEM = UTC
31
+
START_TIME = 2025-01-15T00:00:00.000
32
+
STOP_TIME = 2025-01-15T01:00:00.000
33
+
ATTITUDE_TYPE = QUATERNION
34
+
INTERPOLATION_METHOD = LINEAR
35
+
INTERPOLATION_DEGREE = 1
36
+
META_STOP
37
+
38
+
2025-01-15T00:00:00.000 0.68574 0.69573 0.15380 0.14397
39
+
2025-01-15T00:20:00.000 0.67893 0.70312 0.15010 0.14856
40
+
2025-01-15T00:40:00.000 0.67212 0.71045 0.14635 0.15315
41
+
2025-01-15T01:00:00.000 0.66530 0.71771 0.14256 0.15773
42
+
|}
43
+
44
+
let test_parse_quaternion () =
45
+
let aem = check_ok "parse" (Aem.of_string quaternion_example) in
46
+
Alcotest.(check string) "version" "1.0" aem.header.version;
47
+
Alcotest.(check string) "originator" "NASA/GSFC" aem.header.originator;
48
+
Alcotest.(check int) "segments" 1 (List.length aem.segments);
49
+
let seg = List.hd aem.segments in
50
+
Alcotest.(check string) "name" "AURA" seg.metadata.object_name;
51
+
Alcotest.(check string) "id" "2004-026A" seg.metadata.object_id;
52
+
Alcotest.(check string) "type" "QUATERNION" seg.metadata.attitude_type;
53
+
Alcotest.(check string) "frame_a" "EME2000" seg.metadata.ref_frame_a;
54
+
Alcotest.(check string) "frame_b" "SC_BODY_1" seg.metadata.ref_frame_b;
55
+
Alcotest.(check string) "dir" "A2B" seg.metadata.attitude_dir;
56
+
Alcotest.(check int) "data points" 4 (Array.length seg.data);
57
+
let ad0 = seg.data.(0) in
58
+
match ad0.attitude with
59
+
| Aem.Euler _ -> Alcotest.fail "expected Quaternion"
60
+
| Aem.Quaternion q ->
61
+
check_float "q1" 0.68574 q.q1;
62
+
check_float "q2" 0.69573 q.q2;
63
+
check_float "q3" 0.15380 q.q3;
64
+
check_float "qc" 0.14397 q.qc
65
+
66
+
(* ------------------------------------------------------------------ *)
67
+
(* Euler angle example *)
68
+
(* ------------------------------------------------------------------ *)
69
+
70
+
let euler_example =
71
+
{|CCSDS_AEM_VERS = 1.0
72
+
CREATION_DATE = 2025-03-01T00:00:00
73
+
ORIGINATOR = ESA
74
+
75
+
META_START
76
+
OBJECT_NAME = ENVISAT
77
+
OBJECT_ID = 2002-009A
78
+
CENTER_NAME = EARTH
79
+
REF_FRAME_A = EME2000
80
+
REF_FRAME_B = SC_BODY_1
81
+
ATTITUDE_DIR = A2B
82
+
TIME_SYSTEM = UTC
83
+
START_TIME = 2025-03-01T00:00:00.000
84
+
STOP_TIME = 2025-03-01T00:10:00.000
85
+
ATTITUDE_TYPE = EULER_ANGLE
86
+
META_STOP
87
+
88
+
2025-03-01T00:00:00.000 45.123 -12.456 178.901 0.0
89
+
2025-03-01T00:05:00.000 45.234 -12.567 179.012 0.0
90
+
2025-03-01T00:10:00.000 45.345 -12.678 179.123 0.0
91
+
|}
92
+
93
+
let test_parse_euler () =
94
+
let aem = check_ok "parse" (Aem.of_string euler_example) in
95
+
let seg = List.hd aem.segments in
96
+
Alcotest.(check string) "type" "EULER_ANGLE" seg.metadata.attitude_type;
97
+
Alcotest.(check int) "data points" 3 (Array.length seg.data);
98
+
let ad0 = seg.data.(0) in
99
+
match ad0.attitude with
100
+
| Aem.Quaternion _ -> Alcotest.fail "expected Euler"
101
+
| Aem.Euler e ->
102
+
check_float "angle_1" 45.123 e.angle_1;
103
+
check_float "angle_2" (-12.456) e.angle_2;
104
+
check_float "angle_3" 178.901 e.angle_3
105
+
106
+
(* ------------------------------------------------------------------ *)
107
+
(* Multi-segment *)
108
+
(* ------------------------------------------------------------------ *)
109
+
110
+
let multi_segment =
111
+
{|CCSDS_AEM_VERS = 1.0
112
+
CREATION_DATE = 2025-01-15T00:00:00
113
+
ORIGINATOR = TEST
114
+
115
+
META_START
116
+
OBJECT_NAME = SAT1
117
+
OBJECT_ID = 2020-001A
118
+
CENTER_NAME = EARTH
119
+
REF_FRAME_A = EME2000
120
+
REF_FRAME_B = SC_BODY_1
121
+
ATTITUDE_DIR = A2B
122
+
TIME_SYSTEM = UTC
123
+
START_TIME = 2025-01-15T00:00:00.000
124
+
STOP_TIME = 2025-01-15T01:00:00.000
125
+
ATTITUDE_TYPE = QUATERNION
126
+
META_STOP
127
+
128
+
2025-01-15T00:00:00.000 0.5 0.5 0.5 0.5
129
+
2025-01-15T01:00:00.000 0.6 0.4 0.5 0.4796
130
+
131
+
META_START
132
+
OBJECT_NAME = SAT1
133
+
OBJECT_ID = 2020-001A
134
+
CENTER_NAME = EARTH
135
+
REF_FRAME_A = EME2000
136
+
REF_FRAME_B = SC_BODY_1
137
+
ATTITUDE_DIR = A2B
138
+
TIME_SYSTEM = UTC
139
+
START_TIME = 2025-01-15T02:00:00.000
140
+
STOP_TIME = 2025-01-15T03:00:00.000
141
+
ATTITUDE_TYPE = QUATERNION
142
+
META_STOP
143
+
144
+
2025-01-15T02:00:00.000 0.7 0.3 0.5 0.3873
145
+
2025-01-15T03:00:00.000 0.8 0.2 0.5 0.2449
146
+
|}
147
+
148
+
let test_multi_segment () =
149
+
let aem = check_ok "parse" (Aem.of_string multi_segment) in
150
+
Alcotest.(check int) "segments" 2 (List.length aem.segments);
151
+
let seg2 = List.nth aem.segments 1 in
152
+
Alcotest.(check int) "seg2 points" 2 (Array.length seg2.data);
153
+
match seg2.data.(0).attitude with
154
+
| Aem.Euler _ -> Alcotest.fail "expected Quaternion"
155
+
| Aem.Quaternion q -> check_float "seg2 q1" 0.7 q.q1
156
+
157
+
(* ------------------------------------------------------------------ *)
158
+
(* Roundtrip *)
159
+
(* ------------------------------------------------------------------ *)
160
+
161
+
let test_roundtrip () =
162
+
let aem = check_ok "parse1" (Aem.of_string quaternion_example) in
163
+
let kvn = Aem.to_string aem in
164
+
let aem2 = check_ok "parse2" (Aem.of_string kvn) in
165
+
Alcotest.(check string) "name" aem.header.originator aem2.header.originator;
166
+
Alcotest.(check int)
167
+
"segments" (List.length aem.segments)
168
+
(List.length aem2.segments);
169
+
let seg1 = List.hd aem.segments and seg2 = List.hd aem2.segments in
170
+
Alcotest.(check string)
171
+
"object_name" seg1.metadata.object_name seg2.metadata.object_name;
172
+
Alcotest.(check int)
173
+
"data points" (Array.length seg1.data) (Array.length seg2.data);
174
+
match (seg1.data.(0).attitude, seg2.data.(0).attitude) with
175
+
| Aem.Quaternion q1, Aem.Quaternion q2 ->
176
+
check_float "q1" q1.q1 q2.q1;
177
+
check_float "q2" q1.q2 q2.q2;
178
+
check_float "q3" q1.q3 q2.q3;
179
+
check_float "qc" q1.qc q2.qc
180
+
| _ -> Alcotest.fail "attitude type mismatch on roundtrip"
181
+
182
+
let test_empty () =
183
+
let aem = check_ok "empty" (Aem.of_string "") in
184
+
Alcotest.(check int) "no segments" 0 (List.length aem.segments)
185
+
186
+
let suite =
187
+
( "aem",
188
+
[
189
+
Alcotest.test_case "parse quaternion" `Quick test_parse_quaternion;
190
+
Alcotest.test_case "parse Euler" `Quick test_parse_euler;
191
+
Alcotest.test_case "multi-segment" `Quick test_multi_segment;
192
+
Alcotest.test_case "roundtrip" `Quick test_roundtrip;
193
+
Alcotest.test_case "empty" `Quick test_empty;
194
+
] )