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stfov stsdas.graphics.stplot


NAME · USAGE · DESCRIPTION · PARAMETERS · EXAMPLES · BUGS · SEE_ALSO

NAME

stfov -- Draw the HST instrument field of view over an image.

USAGE

stfov input ra dec apertures center_ap orient

DESCRIPTION

The stfov task draws the science instrument apertures of the Hubble Space Telescope (HST) on a grayscale image. This task can be used to create overlays of the HST Field-of-View (FOV) onto images.

This task is basically a "wrapper" script using the task disconlab but with a simplified user interface. The input image can be any image with WCS parameters in the header or a Digital Sky Survey (DSS) image. In the later case, the gasp package must be loaded and the task makewcs will be executed on such an image.

PARAMETERS

input [file name]
An image containing the world coordinate system (WCS) information is needed to properly scale and rotate the HST apertures. If a DSS image is used, it will be populated with WCS keywords by this task.
ra = "" [string]
The right ascension (in H:M:S or decimal HOURS, NOT in decimal degrees) at which the center aperture will be located. If the value is NULL, the CRVAL1 value (in this case, in decimal degrees) in the image header will be used.
dec = "" [string]
The declination (in D:M:S or decimal degrees) at which the center aperture will be located. If the value is NULL, the CRVAL2 value (in this case, in decimal degrees) in the image header will be used.
apertures = "sm3b" [string]
A list of aperture names to be plotted. The names may be separated by spaces or commas. See the Aperture specification section in the SIAPER task help file for a complete listing of available apertures.

Several aliases are provided: "launch", "sm1" (or "sm93"), "sm2" (or "sm97"), "sm3b" (or "sm2002") include all apertures of instruments available on HST after launch (in 1990), after the first service mission (in 1993), after the second service mission (in 1997) and after the service mission 3B (in 2002), respectively. The service mission 3A did not replace any science instrument.

The names can also be placed in a text file. To specify the file name as the parameter value proceeded with the "@" character.

center_ap = "ota" [string]
The aperture which will be located at the specified right ascension and declination. Any aperture can be specified. This parameter does not support pattern matching; an exact aperture name needs to be specified. See the Aperture specification section in the SIAPER task help file for a complete listing of available apertures.

Some more commonly used apertures include:

aperture	description
--------        -----------
FGS1		optimum position in FGS1 (also: FGS2, FGS3)
NIC1FIX		NICMOS camera 1 (also: NIC2FIX, NIC3FIX)
OV50		clear aperture for STIS CCD
UPC1		optimum location on PC1 (also: UWF2, UWF3, UWF4)
UPC1FIX		center of PC1 (also: UWF2FIX, UWF3FIX, UWF4FIX)
UWFALL		~14" from apex of pyramid, on WF3
XK96NLRG	FOC, 512x512, 16 bit pixels, includes COSTAR
X96NLRG		same as XK96NLRG but before COSTAR

(Aperture names can be either upper or lower case.)
orient = 0. [real]
The spacecraft roll measured in degrees east from north. It is the same angle as that required in the Phase II proposal template (see Proposal Instructions for complete definition).
(color) = "blue" [string, allowed values: red, green, yellow, blue, white]
The color used to draw apertures and labels.
(append) = no [boolean]
Append a new FOV on an existing chart. If this switch is set to yes, only the newly specified FOV will be overplotted on the existing image, together with previously plotted FOV and labels. When running stfov on a new field for the first time, this switch should be set to no.
(interactive) = no [boolean]
Interactive mode to get photometry estimation.

This task provides a rudimentary way of estimating brightness magnitudes of stars in the field. If this switch is turned on, if will start the task imexamine and the user can move the cursor to any star position and hit the a key to get the magnitude. Hitting the q key will quit imexamine.

The zero point is based on DSS images and depends on the exposure time (from the image header keyword EXPOSURE):

magzero = 28.0 + log10 (EXPOSURE/60.) * 2.5

The error of magnitude is about 1.0. For over- and under-exposed stars, the errors will be much larger. If the keyword EXPOSURE does not exist, magzero is arbitrarily set to 0.

EXAMPLES

1. Use CRVAL1 and CRVAL2 of the image header as RA and Dec of the aperture center:

st> stfov dss.fits "" "" "sm3b" "ota" 0.

2. Specify RA in hours and Dec in degrees, centered at WF3 of WFPC2 with orient of 30 degrees:

st> stfov dss.fits "4:20:40" "28:42:05" "sm3b" "uwf3" 30.

3. Plot several FOV's on the same image (the label will only show the center aperture and orient of the first plot):

st> stfov dss.fits "" "" "sm3b" "uwf3" 30. color=red append-
st> stfov dss.fits "" "" "sm3b" "uwf3" 90. color=yellow append+

BUGS

Do not append FOV's by running stfov and siaper on the same image.

SEE ALSO

siaper, disconlab, imexamine


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