Trail parameters not in current schema will be needed in production

[ariheinze]

While not needed for DP0.3, in production we need trail length in arcseconds, trail position angle (PA) relative to celestial North (+Dec). Importantly, the trail position angle must be relative to celestial coordinates, not pixel coordinates (which are useless to downstream clients that don't have access to the image WCS). Ideally, we'd also have the uncertainty on both parameters (trail length and trail PA). We also need along-trail and across-trail astrometric uncertainty, for orbit-fitting.

[mschwamb]

@ariheinze why are the properties in the associated DIASource entry for the observation not sufficient for this? See the schema here: https://dm.lsst.org/sdm_schemas/browser/apdb.html#DiaSource

These seem to be the parameters you're looking for:

trailRa double deg Right ascension coordinate of centroid for trailed source model. [pos.eq.ra]
trailRaErr float deg Uncertainty of trailRa. [stat.error;pos.eq.ra]
trailDec double deg Declination coordinate of centroid for trailed source model. [pos.eq.dec]
trailDecErr float deg Uncertainty of trailDec. [stat.error;pos.eq.dec]
trailLength float arcsec Maximum likelihood fit of trail length.
trailLengthErr float nJy Uncertainty of trailLength.
trailAngle float deg Maximum likelihood fit of the angle between the meridian through the centroid and the trail direction (bearing).
trailAngleErr float nJy Uncertainty of trailAngle.
trailFlux_trailRa_Cov float Covariance of trailFlux and trailRa. [stat.covariance]
trailFlux_trailDec_Cov float Covariance of trailFlux and trailDec. [stat.covariance]
trailFlux_trailLength_Cov float Covariance of trailFlux and trailLength [stat.covariance]
trailFlux_trailAngle_Cov float Covariance of trailFlux and trailAngle [stat.covariance]
trailRa_trailDec_Cov float Covariance of trailRa and trailDec. [stat.covariance]
trailRa_trailLength_Cov float Covariance of trailRa and trailLength. [stat.covariance]
trailRa_trailAngle_Cov float Covariance of trailRa and trailAngle. [stat.covariance]
trailDec_trailLength_Cov float Covariance of trailDec and trailLength. [stat.covariance]
trailDec_trailAngle_Cov float Covariance of trailDec and trailAngle. [stat.covariance]
trailLength_trailAngle_Cov float Covariance of trailLength and trailAngle [stat.covariance]
trailLnL float Natural log likelihood of the observed data given the trailed source model. [stat.likelihood]
trailChi2 float Chi^2 statistic of the trailed source model fit. [stat.fit.chi2]
trailNdata int The number of data points (pixels) used to fit the trailed source model.