psAstrometry questions

[gusciora@…]

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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.)

[Paul Price]

* This bug has been marked as a duplicate of 123 *

[Paul Price]

Should be fixed in SDRS-07 and ADD-06 (7 September 2004).