id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
125	psAstrometry questions	gusciora@…	Paul Price	"-------------------------------------------------------
For psGrommitAlloc(), we don't know how to calculate several members of the
psGrommit structure based on the info provided in psExposure.  Those members
are:
    grommit->abberationMag
    grommit->height
    grommit->wavelength
    grommit->lapseRate
    grommit->refractA
    grommit->refractB
    grommit->siderealTime

I calculate the following
    grommit->latitude = exposure->dec
Is that correct?  Does the latitude equal the declination?

Also, I do:
    grommit->longitudeOffset = exposure->ra
Is that correct?

Why is psGrommitAlloc() part of the public API, but then p_psGrommitFree()
is a private function?

In psGrommitAlloc(), if the ""exposure"" parameter is NULL, then I return
NULL.  Is that correct?
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We assume that if a cell has more than one readout, all readouts have the
same coordinates.  Is that true?

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In psCellinChip():
    1: if we find no cell with has this coordinate, we return NULL.
    2: if either the chip or chipCoord argument is NULL, I return NULL.
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I have run across the tangentPlane<->FocalPlane transformation many times,
which is a plane distort transformation.  Where should I get the 3rd and 4th
arguments for those transformations from?
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psCoordCelltoSky(): my implementation requires a new psGrommit be created
for each transformation.  This is because the ""psExposure"" is a part of the
psFPA struct, but ""psGrommit"" is not.  Should we add psGrommit to the psFPA
struct?
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psCoordCelltoSkyQuick() converts linear cell coords to spherical sky
coords.  It is supposed to use the cell->toSky transform.  However, that
transform is linear transform.  How can I produce spherical coordinates from
it?

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In psCoordSkytoCell(), how do I determine the psGrommit, which is necessary
to perform the Sky->FPA transform?

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psCoordSkytoCellQuick() How should I perform this transfrom?

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This is a question on the polynomial functions:
Page 39 of the SDRS talks about using the mask terms in the evaluation of
various polynomials.  Should the psEvalPoly() functions take that mask into
consideration?  (NOTE: I chose to implement the coordinate transfromation
without a call to the psEvalPoly() function.)"	defect	closed	high		IPP SDRS	unspecified	normal	duplicate