Purpose
Starting with sidereal tracking with objects centered on slits,
offset the telescope and begin tracking at a non-sidereal rate
while acquiring an exposure. At the end of the exposure, return
telescope to starting position and restore sidereal track rates.
Usage
driftscan [-v -red -blue] <length>
Arguments
-v = verbose mode
-blue = use blue side only
-red = use red side only
length = length of drift scan [arcsec]
Output
Restrictions
- Slit must be oriented N/S so that drift scanning is purely E/W.
Exit values
0 = normal completion
1 = wrong number of arguments
Example
1) Acquire a spectrum while tracking at a non-sidereal rate
over a 10 arcsec length
driftscan 10