[MOIMS-NAV-EXEC] Draft update to Time scales, reference frames, element sets content

[Berry, David S (3920)]

Hi Brian, Dan:


The first paragraph here suggests to me that the "ONSTATION" elements would not be appropriate for incorporation in a standard (rationale:  "inconsistent", "adapted", "many definitions depending on their use"). I think these could be appropriate for an ICD (Interface Control Document), but they sound to be de facto non-standardized.

David



From: "SWINBURNE, Brian [UK]" <brian.swinburne at airbus.com>
Date: Wednesday, February 21, 2018 at 3:29 AM
To: "Oltrogge, Daniel" <doltrogge at agi.com>, "Berry, David S (3920)" <david.s.berry at jpl.nasa.gov>, "moims-nav-exec at mailman.ccsds.org" <moims-nav-exec at mailman.ccsds.org>
Subject: RE: [MOIMS-NAV-EXEC] Draft update to Time scales, reference frames, element sets content

Hi Dan

Regarding “ONSTATION” elements it seems our documentation is a little inconsistent and they are also referred to as “Adapted (or non-singular) orbit elements” for which there appears to be many definitions depending on their use, our definition is as follows:

Adapted (or non singular) orbit parameters
a                                  semi-major axis (km)
ex = e cos(• + •)        eccentricity vector
ey = e sin(• + •)
ix = sin i cos(•)           inclination vector
iy = sin i sin(•)
• = • + • + M - • or • + • + v - •      mean or true longitude (deg)
• is the sidereal time.
For small values of inclination, ix & iy can be considered as angles and displayed in degrees.

Best Regards

Brian

From: MOIMS-NAV-EXEC [mailto:moims-nav-exec-bounces at mailman.ccsds.org] On Behalf Of Oltrogge, Daniel
Sent: 20 February 2018 22:45
To: Berry, David S (3920); moims-nav-exec at mailman.ccsds.org
Subject: [MOIMS-NAV-EXEC] Draft update to Time scales, reference frames, element sets content

All –

Thanks to additional help from Vallado and Patrick, we’ve continued to evolve the draft SANA content.

“Track Changes” has been enabled so that you can see the proposed modifications.

Brian Swinburne – Note that per your request (I didn’t forget!), I’ve added “ONSTATION” elements.  But I believe that there may be several such definitions.  Please research the specific version that you are using and provide me with a detailed description that we can replace my draft (placeholder) text with.

David, with the exception of this replacement text from Brian, I believe that this document version may be ready for all to review to ensure that it meets the needs of the organizations that each of us represent.

Dan

Daniel L. Oltrogge
Director, Center for Space Standards and Innovation
Analytical Graphics, Incorporated
Voice: 719-482-4552   ҉   E-mail: oltrogge at agi.com<mailto:oltrogge at agi.com>



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