[MOIMS] SC14: Common Data Format for Collision Avoidance
Nestor.Peccia at esa.int
Nestor.Peccia at esa.int
Sun Nov 7 15:11:42 UTC 2004
Please review this and we discuss the potential liaison in our Plenary on 18th
Nov 2004.
ciao
nestor
|--------+----------------------------->
| | "Adrian J. Hooke" |
| | <adrian.j.hooke at jpl|
| | .nasa.gov> |
| | |
| | 04/11/2004 23:03 |
| | |
|--------+----------------------------->
>----------------------------------------------------------------------------|
| |
| To: Nestor Peccia <nestor.peccia at esa.int> |
| cc: peter.shames at jpl.nasa.gov, adrian.j.hooke at jpl.nasa.gov |
| Subject: SC14: Common Data Format for Collision Avoidance |
>----------------------------------------------------------------------------|
Nestor: ISO/TC20/SC14 has embarked on a new project to develop a "Common Data
Format for Collision Avoidance". Could you please review the outline below and
indicate if you think that one or more WGs (e.g., Information Packaging and
Registries?) in your MOIMS Area in SC13 should establish a liaison with this
activity in order to help them with the information technology aspects?
Best regards
Adrian
Conjunction Assessment Data and Information Exchange
Common Data Format for Collision Avoidance
The objective of this standard is to enable exchange of information and
data so that parties affected by potential encounters among spacecraft can
confirm and refine collision predictions and develop mutually satisfactory
maneuvers or other mitigations.
When a spacecraft operator perceives a potential collision with another
object, either the following information shall be provided to other
operators or stakeholders involved or affected by outcomes or justification
for disregarding some data elements because it can be demonstrated that
they do not affect the current collision estimate.
1. Orbital data that supports the assessment of the potential
collision:
1. Source of the data
2. Measurement and process uncertainties associated with the
data
3. Either direct observational data in engineering units from
which orbit estimates can be derived? or ? two line element sets
and associated covariances ? or ? state vectors and direction
cosines
4. Spatial and temporal reference frame in which the data
reside, including specific release or version of that standard
reference frame.
2. Physical models or simulations with which that data was employed
to predict the potential collision
1. Geopotential approximation
2. Perturbations and the manner in which they are included in
propagated states including: atmospheric drag, ocean and central
body mass distribution variations (tides), radiative momentum
transfer (light pressure, etc.), multi-body effects, ?
3. Atmospheric and space environmental models and
approximations, including source and release or version.
4. Orbit estimation and propagation technique (Kalman filter,
least squares, etc.)
5. Interoperable computer code that incorporates these
matters, if possible.
3. Numerical and computational information necessary to reproduce
results
1. Temporal and/or spatial computational step size.
2. Integration and differencing scheme.
4. Practices and Procedures through which data, models, and
numerics were employed to produce the collision estimate.
The formats for these elements of information is as follows:
I. Data Source
a. Location
i. Latitude and
Longitude (Re: WGS 84, degrees/min/sec/thousandths of seconds)
ii. Altitude (to
decimeter level)
b. Sensor Characteristics
i. Sensor Type
(angles/range or angles only)
ii. Sensor Resolution
(range and angular precision and method by which such were determined)
II. Measurement and Process Uncertainties
a. Sensor measurement uncertainties (precision)
b. Data acquisition uncertainties (sensor sentivities, data processing,
and recording imprecision)
III. Spatial and Temporal Reference Frame
a. Standard Definition (ECF, ECEF, TEME, etc.)
b. IERS or equivalent Earth reference motion description
IV. Geopotential/Force Model
a. General description (Two body, J2000, J2, J4, etc.)
b. Order of approximation
c. Numerical precision for embodied mathematical functions
V. Perturbations
a. Atmospheric Drag
i. Object drag
characteristics and assumptions (Cd)
b. Tides
i. Ocean Tidal
Effects
ii. Earth tide
effects
c. Radiation Pressure
i. Momentum
transfer model
ii.
Emissivity/Absorptivity/Scattering Model
iii. Incident radiation
description
1. Direct Solar Radiation
2. Indirect Reflected radiation/Earth Albedo/etc.
d. Multi-Body Effects
i. Lunar/Solar/and
Planetary forces included
VI. Atmospheric Models
a. General Description (Jacccia, etc.)
b. Data/Model release date or version.
VII. Orbit estimation and Propagation Approach
a. General Description (Kalman Filter, Least Squares, analytical,
etc.)
b. Specific Essential Details (Update interval, state variables, etc.)
VIII. Numerical and Computational Information
a. Operating system (version)
b. Integration technique (Gauss-Jackson, etc.) and order of
approximation.
IX. Practices and procedures
a. Data and unit conversions
b. Data storage and manipulation which might affect numerical precision
c. Narrative discussion of the approach to developing the collision
estimate.
Any of the above may be provided by reference to standard, widely available
sources, such as texts, ISO standards, archive technical literature, or
similar sources. Any of the above which are recurring or configuration
controlled may be submitted or archived where available to stakeholders and
need not be refreshed or resubmitted unless there are changes.
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