Purpose
Acquire a sequence of RED and BLUE images using a 9-position box
pattern. At each dither position, acquire a long U band exposure
of specified duration on the blue side, while on the red side
acquiring shorter V and R exposures of such duration such that
the red and blue exposures will complete simultaneously.
The offsets are made in CELESTIAL coordinates. The dither pattern
employed is
2 8 4
6 1 7
3 9 5
Usage
bxy9udf [-t]
Options
-t = test. Use minimum exposure time on each sides which will
cause the 2 red images to complete in the same time as the blue image.
Restrictions
- Observer must insert appropriate focus values for U, V, and R
filters into the script to define the variables Ufocus, Vfocus,
and Rfocus.
- Observer must insert appropriate values for x and y offsets
(arcsec) into variables x and y.
- Observer must insert desired value for U-band exposure time
in variable exptimeb.
Example