Implement MISP Time System instant #198
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Any thoughts on this PR? Changes or general suggestions? |
| @@ -226,6 +226,70 @@ public TaiInstant convertToTai(UtcInstant utcInstant) { | |||
| */ | |||
| public abstract UtcInstant convertToUtc(TaiInstant taiInstant); | |||
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| /** | |||
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Having thought a bit, my view is that we should make UTC and TAI the primary time scales, and others like MISP secondary. This avoids the risk that UtcRules ends up with conversion methods for all possible time scales (n x n combination problem).
As such, please move these methods to MispInstant (as necessary). Conversion from MISP to UTC will need to go via TaiInstant
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Still to be addressed, but I think I understand what is needed.
| // 59643L is the MJD for 2022-03-05 | ||
| // 40587L is the MJD for 1970-01-01 | ||
| assertEquals((59643L - 40587L) * 24 * 60 * 60 + 37, misp.getMispSeconds()); | ||
| assertEquals(0, misp.getNano()); |
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I'm not seeing the 8.000082 anywhere?
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The 8.000082 is in the instant that we are converting. I can rework the example (or the comment) if it isn't clear.
This implements the MISP time system as described in the MISB Motion Imagery Handbook (downloadable from https://nsgreg.nga.mil/doc/view?i=5306 - sorry, direct links frequently broken). The implementation follows the
TaiInstantimplementation, and makes use of the TAI conversion routines where practical.Resolves #194
The PR includes unit tests for all added code.
There is a change to the
UtcRulesimplementation that adds an abstract method. That won't be source compatible for anyone implementing their own rules (i.e. its arguably an API break). It is not strictly necessary to do so, and although I think the implementation makes more sense in theSystemUtcRules, I could see a case for not doing it that way. I'll update the PR to avoid that if required.