Spacecraft Orbit Epoch V&V

Topics related to QA and V&V of GMAT features

Spacecraft Orbit Epoch V&V

Postby jjkparker » Tue Mar 13, 2012 5:52 pm

From inspecting the GUI, script interface, and requirements, here is my feature audit for Spacecraft Orbit Epoch.

This topic is no longer being updated. Future work has moved to JIRA.

Initial Status of the Feature
This is a small feature with high visibility. It's used a lot, by everyone. There are no major bugs from a script perspective, but there are some cleanup issues with validation, syntax, and documentation.

References

Requirements
  • "Modified Julian Date (GSFC)" is ambiguous; it should specify the Julian offset. [GMT-591]
  • Requires MJD to allow 10e-6 seconds, but Gregorian only 1e-3. Is this accurate, and why require a less-precise Gregorian epoch? And is 10e-6 supposed to be 1e-6, or 1e-5?

JIRA issues
No current JIRA issues regarding this feature.

Bugzilla bugs
I did a search in the "Spacecraft Orbit Epoch (FRR-2)" component and for all bugs with "epoch" in the summary, and found these open issues:

* #2568 - GMAT should not allow a spacecraft epoch beyond 01 Jan 2100 00:00:00.000 UTCGregorian
Recommendation: Discuss as open spec issue [GMT-592]

* #2571 - Epoch Is Not Reset When Default Mission Is Loaded
Recommendation: Confirm and fix (Fix by: R2012a, Priority: P1) [GMT-2455]

* #2491 - Cannot pass Spacecraft property (Epoch) as input or output
Recommendation: Reassign to GMAT Functions feature (Fix by: R2013a, Priority: P1) [GMT-2380]

* #1381 - Incorrect Epoch value when passing SC to Matlab
Recommendation: Reassign to MATLAB Functions feature (Fix by: R2013a, Priority: P1) [GMT-1547]

* #1088 - Script Syntax Change
Recommendation: Document [GMT-1400]

Failing tests
  • Epoch_Validation_Epoch

Unreported issues
1. In command mode, setting Epoch to invalid types isn't caught (Epoch_Validation_Epoch test).
Recommendation: Fix (Fix by: R2012a, Priority: P1) [GMT-584]

2. There are three formats for getting/setting Epoch:
  1. Spacecraft.DateFormat/Spacecraft.Epoch (set)
  2. Spacecraft.A1ModJulian (get, set in MS only)
  3. Spacecraft.Epoch.A1ModJulian (get, set)
Recommendation: Discuss as an open spec issue. [GMT-585]

3. When you save a script, GMAT puts quotes around a ModJulian date.
Recommendation: Fix (Fix by: R2012a, Priority: P1) [GMT-586]

4. TDB/TCB are settable, but don't appear in the GUI
Recommendation: Add TDB fields to GUI (Fix by: R2012a, Priority: P1) [GMT-587]

5. "TCB not implemented" when trying to set epoch in that format
Recommendation: Hide TCB fields (Fix by: R2012a, Priority: P1) [GMT-588]

6. There's an undocumented parameter Spacecraft.CurrA1MJD
Recommendation: Deprecate this. What's it's purpose? (Fix by: R2012a, Priority: P1) [GMT-589]

7. The Epoch Format GUI widget is sorted somewhat randomly
Recommendation: Fix (Fix by: R2012a, Priority: P1) [GMT-590]

Documentation
The old reference page is in pretty good shape; no big changes needed here. This feature is lumped in with the Spacecraft resource page, which is a good idea from my perspective.
Joel J. K. Parker
Flight dynamics engineer, GMAT team
http://gmatcentral.org
jjkparker
 
Posts: 617
Joined: Thu Jan 07, 2010 9:48 pm
Location: NASA Goddard Space Flight Center, Greenbelt, MD

Re: Spacecraft Orbit Epoch V&V

Postby dev-wcs » Thu Mar 15, 2012 2:24 pm

• References
--- Common Tasks section specifies that we can set TDB - that is a future enhancement, right?
--- Draft Field Spec - upper and lower bounds for Epoch are not as coded

• Requirements
--- Agreed - the offset should be specified
--- I assume it should be 1e-6. I cannot comment on accuracy requirements or why they are different.

• Unreported Issues:
--- 1. Agreed - should be fixed for this release.
--- 2. I would prefer to choose between 2 and 3, but as you say, this probably needs some discussion.
--- 3. Agree. Document the difference. Is there some reason why we shouldn't make them consistent in a future build? (Other than needing to modify a bunch of scripts)

• Documentation
--- Old reference page does not specify an upper bound for Epoch. That should be in there.


• Other issues/comments:
--- all conversions are not implemented in the TimeSystemConverter (e.g. TCB to TAI)
--- there are Bugs for time conversions still out there on Bugzilla, I believe
--- will we be removing A1 time and passing TAI time around in the code at some time in the future?
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Re: Spacecraft Orbit Epoch V&V

Postby jjkparker » Tue Mar 20, 2012 3:32 pm

Wendy, I made some changes to the feature audit (marked with *). Can you take a second look and comment as appropriate?
Joel J. K. Parker
Flight dynamics engineer, GMAT team
http://gmatcentral.org
jjkparker
 
Posts: 617
Joined: Thu Jan 07, 2010 9:48 pm
Location: NASA Goddard Space Flight Center, Greenbelt, MD

Re: Spacecraft Orbit Epoch V&V

Postby dev-wcs » Tue Mar 20, 2012 4:41 pm

Bugs:

2568 - Steve had changed the upper date to 28 February. It looks like the remaining issue is what to do if propagation goes beyond the epoch limits - if it is decided that that should throw an exception and if that is an issue that needs to be taken care of right away, then I agree that it should be P1 and fixed now.

2571 - this does not seem to be an issue any longer, since 2568 was fixed (as it was originally written anyway)

2491 - Agree with recommendation
1381 - Agree with recommendation
1088 - Agree with recommendation

Unreported issues
2. MS? Does that mean in Main Sequence but not in GmatFunctions? Agree that this needs discussion.
3. Agreed - should be fixed.
4. I thought there was an issue with this - didn't Russell ask for this some time back and there was some reason why we didn't do it?
5. Agree - hide those for now - conversion is not implemented fully.
6. Agree - deprecate this.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Views expressed are my own and
do not necessarily reflect those
of my employer, or anyone else.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
dev-wcs
 
Posts: 97
Joined: Tue Jun 10, 2008 1:01 pm

Re: Spacecraft Orbit Epoch V&V

Postby jjkparker » Tue Mar 20, 2012 5:19 pm

dev-wcs wrote:2568 - Steve had changed the upper date to 28 February. It looks like the remaining issue is what to do if propagation goes beyond the epoch limits - if it is decided that that should throw an exception and if that is an issue that needs to be taken care of right away, then I agree that it should be P1 and fixed now.

Ok, maybe this is a bigger issue that we should discuss. I changed my recommendation above.

dev-wcs wrote:2571 - this does not seem to be an issue any longer, since 2568 was fixed (as it was originally written anyway)

I'll check it into JIRA as "Resolved" and verify it.

dev-wcs wrote:2. MS? Does that mean in Main Sequence but not in GmatFunctions? Agree that this needs discussion.

Sorry, MS = Mission Sequence (command mode). I'm assuming it's the same in functions, but I haven't tried it.

dev-wcs wrote:4. I thought there was an issue with this - didn't Russell ask for this some time back and there was some reason why we didn't do it?

Hmm, I don't know. We may need to add it to the GUI and start testing, then pull it later if it ends up being big.
Joel J. K. Parker
Flight dynamics engineer, GMAT team
http://gmatcentral.org
jjkparker
 
Posts: 617
Joined: Thu Jan 07, 2010 9:48 pm
Location: NASA Goddard Space Flight Center, Greenbelt, MD

Re: Spacecraft Orbit Epoch V&V

Postby jjkparker » Fri Mar 23, 2012 1:26 pm

One addition:

jjkparker wrote:7. The Epoch Format GUI widget is sorted somewhat randomly
Recommendation: Fix (Fix by: R2012a, Priority: P1)
Joel J. K. Parker
Flight dynamics engineer, GMAT team
http://gmatcentral.org
jjkparker
 
Posts: 617
Joined: Thu Jan 07, 2010 9:48 pm
Location: NASA Goddard Space Flight Center, Greenbelt, MD


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