ISO 13541:2021

INTERNATIONAL ISO
STANDARD 13541
Second edition
2021-06
Space data and information transfer
systems — Attitude data messages
Systèmes de transfert des informations et données spatiales —
Messages de données d'attitude
Reference number
©
ISO 2021
© ISO 2021
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Foreword
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This document was prepared by the Consultative Committee for Space Data Systems (CCSDS) (as
CCSDS 504.0-B-1 Cor.1, July 2015) and was adopted (without modifications) by Technical Committee
ISO/TC 20, Space vehicles, Subcommittee SC 13, Space data and information transfer systems.
This second edition cancels and replaces the first edition (ISO 13541:2010), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— adds clarifying text to 1.3, Conventions and Definitions.
Any feedback or questions on this document should be directed to the user’s national standards body.
.
A complete listing of these bodies can be found at www.iso.org/members.html
CCSDS RECOMMENDED STANDARD FOR ATTITUDE DATA MESSAGES
CONTENTS
Section Page
1  INTRODUCTION . 1-1

1.1  PURPOSE . 1-1
1.2  SCOPE AND APPLICABILITY . 1-1
1.3  CONVENTIONS AND DEFINITIONS. 1-2
1.4  STRUCTURE OF THIS DOCUMENT. 1-2
1.5  REFERENCES . 1-3

2  OVERVIEW . 2-1

2.1  ATTITUDE DATA MESSAGE TYPES . 2-1
2.2  ATTITUDE PARAMETER MESSAGE (APM) . 2-1
2.3  ATTITUDE EPHEMERIS MESSAGE (AEM) . 2-2
2.4  EXCHANGE OF MULTIPLE MESSAGES . 2-2
2.5  DEFINITIONS . 2-2

3  ATTITUDE PARAMETER MESSAGE (APM) . 3-1

3.1  OVERVIEW . 3-1
3.2  APM CONTENT . 3-1
3.3  APM EXAMPLES . 3-10

4  ATTITUDE EPHEMERIS MESSAGE (AEM) . 4-1

4.1  OVERVIEW . 4-1
4.2  AEM CONTENT . 4-1
4.3  AEM EXAMPLE . 4-12

5  ADM SYNTAX . 5-1

5.1  INTRODUCTION . 5-1
5.2  LINES . 5-1
5.3  KEYWORDS . 5-1
5.4  VALUES . 5-2
5.5  UNITS . 5-4
5.6  COMMENTS . 5-4

6  SECURITY . 6-1

6.1  INTRODUCTION . 6-1
CCSDS 504.0-B-1 Page vi May 2008
CCSDS RECOMMENDED STANDARD FOR ATTITUDE DATA MESSAGES
CONTENTS (continued)
Section Page
6.2  SECURITY CONCERNS WITH RESPECT TO THIS RECOMMENDED
STANDARD . 6-1
6.3  POTENTIAL THREATS AND ATTACK SCENARIOS . 6-2
6.4  CONSEQUENCES OF NOT APPLYING STATED SECURITY TO THE
TECHNOLOGY . 6-2
6.5  DATA SECURITY IMPLEMENTATION SPECIFICS . 6-2

ANNEX A VALUES FOR SELECTED KEYWORDS (NORMATIVE) . A-1
ANNEX B RATIONALE FOR ATTITUDE DATA MESSAGES
(INFORMATIVE) .B-1
ANNEX C ITEMS FOR AN INTERFACE CONTROL DOCUMENT
(INFORMATIVE) . C-1
ANNEX D ABBREVIATIONS AND ACRONYMS (INFORMATIVE) . D-1
ANNEX E INFORMATIVE REFERENCES (INFORMATIVE) .E-1

Figure Page
3-1  APM File Example Using Comments to Denote Updates . 3-10
3-2  APM File Example Using Frame of Another Spacecraft . 3-11
3-3  APM File Example Describing Sensor Frame to Body Frame Transform . 3-11
3-4  APM File Example Describing Orientation of Instrument . 3-12
3-5  APM File Example with Euler Angle Rates . 3-12
3-6  APM File Example with Euler Angle Rates (Repeated Axis) . 3-13
3-7  APM File Example with Mission Elapsed Time . 3-14
3-8  APM File Example with Optional Euler Elements and One Maneuver . 3-15
4-1  AEM Example . 4-12
4-2  AEM Spinner Example . 4-13

Table
3-1  APM Header . 3-2
3-2  APM Metadata . 3-3
3-3  APM Data . 3-4
4-1  AEM File Layout Specifications . 4-2
4-2  AEM Header . 4-3
4-3  AEM Metadata . 4-4
4-4  Types of Attitude Ephemeris Data Lines . 4-8
B-1  Primary Requirements .B-2
B-2  Heritage Requirements .B-3
CCSDS 504.0-B-1 Page vii May 2008
CCSDS RECOMMENDED STANDARD FOR ATTITUDE DATA MESSAGES
CONTENTS (continued)
Table Page
B-3  Desirable Characteristics .B-3
B-4  Applicability of the Criteria to Attitude Data Messages .B-4
B-5  Services Available with Attitude Data Messages .B-4
C-1  Items Recommended for an ICD .C-1

CCSDS 504.0-B-1 Page viii May 2008
CCSDS RECOMMENDED STANDARD FOR ATTITUDE DATA MESSAGES
1 INTRODUCTION
1.1 PURPOSE
1.1.1 This Attitude Data Message (ADM) Recommended Standard specifies two standard
message formats for use in transferring spacecraft attitude information between space
agencies: the Attitude Parameter Message (APM) and the Attitude Ephemeris Message
(AEM). Such exchanges are used for:
– preflight planning for tracking or attitude estimation support;
– scheduling attitude and data processing support;
– carrying out attitude operations;
– performing attitude comparisons;
– carrying out attitude propagations and/or sensor predictions;
– testing to initialize sub-system simulators (communications, power, etc.).
1.1.2 This Recommended Standard includes sets of requirements and criteria that the
message formats have been designed to meet. For exchanges where these requirements do
not capture the needs of the participating agencies, another mechanism may be selected.
1.2 SCOPE AND APPLICABILITY
1.2.1 This document contains two attitude data messages designed for applications
involving data interchange in space data systems. The rationale behind the design of each
message is described in annex B and may help the application engineer to select a suitable
message. Definition of the attitude accuracy underlying a particular attitude message is
outside of the scope of this Recommended Standard and should be specified via Interface
Control Document (ICD) between data exchange participants. Applicability information
specific to each Attitude Data Message format appears in sections 3 and 4, as well as in
annex subsection B3.
1.2.2 This Recommended Standard is applicable only to the message format and content,
but not to its transmission. The transmission of the message between agencies is outside the
scope of this document and should be specified in an ICD or by following a CCSDS standard
on transmission.
1.2.3 Description of the message formats based on the use of the eXtensible Markup
Language (XML) will be available. An XML schema is defined by the CCSDS Recommended
Standard titled ‘XML Specification for Navigation Data Messages’ (reference [5]). Agencies
should specify, via ICD, the ASCII file format to be exchanged (Keyword Value Notation
[KVN] or XML).
CCSDS 504.0-B-1 Page 1-1 May 2008
Cor. 1
CCSDS RECOMMENDED STANDARD FOR ATTITUDE DATA MESSAGES
1.3 CONVENTIONS AND DEFINITIONS
The following conventions apply throughout this Recommended Standard:
a) the words ‘shall’ and ‘must’ imply a binding and verifiable specification;
b) the word ‘should’ implies an optional, but desirable, specification;
c) the word ‘may’ implies an optional specification; and
d) the words ‘is’, ‘are’, and ‘will’ imply statements of fact.
As in some attitude dynamics references, in this document the term ‘nutation’ is used to
mean the motion of the spin axis of a body about an inertial axis. In many other references
this motion is called ‘precession’.
1.4 STRUCTURE OF THIS DOCUMENT
1.4.1 Section 2 provides a brief overview of the CCSDS-recommended Attitude Data
Message types, the Attitude Parameter Me
...