HSTJIT

Name

hstjit

Purpose (one Line)

Read and interpret HST jitter information.

Description

See Tiny Tim User's Manual, Version 6.3, for details.

Calling Sequence

hstjit, image, xsrc_in, ysrc_in, time, deltax, deltay,
undistortedx, undistortedy, distortedx, distortedy,
instr, path=in_path, DISTORT=distort

Inputs

IMAGE - image name to be fit, must be a string
XSRC_IN - x coordinate of object of interest
YSRC_IN - y coordinate of object of interest

Optional Input Parameters

PATH - String, this is the name of the directory where the data are
stored. The actual data directory used is PATH+'/'+image.
The default is '' (blank) and the file would be IMAGE
which would permit putting a leading path on the root.

Keyword Parameters

DISTORT - The input x,y are taken to be in an undistorted reference
plane and will will be converted to the instrumental (distorted)
frame.

Outputs

time - intervals of jitter from start of observation [in seconds]
deltax - delta x-axis jitter in pixels
deltay - delta y-axis jitter in pixels
undistortedx - x coordinate with jitter, undistorted reference frame
undistortedy - y coordinate with jitter, undistorted reference frame
distortedx - x coordinate with jitter, distorted reference frame
distortedy - y coordinate with jitter, distorted reference frame
instr - record of which instrument was used for this observation
rawjitPixelsV2 - raw jitter in pixels, v2 axis
rawjitPixelsV3 - raw jitter in pixels, v3 axis

Common Blocks

Side Effects

Restrictions

Assumes jitter file is in the same directory as the image file.

Procedure

NOTES: The timestep in the jitter file is one value over 3 seconds
Currently does not do distortion for ACS images

Modification History

Written by S. D. Kern, STScI, September 25, 2007.
2007/10/18, SDK, added support for camera specifics ACS, WFPC2
2007/10/24, SDK, conversion of undistorted/distorted coordinates,
output in pixels
2008/04/22, MWB, added support for compressed data files. Fixed
bug on reading wrong input quantity from jitter files.