DEIMOS user script driftscan

Name

driftscan -- acquire image while drifting target across the slit

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] <length>

Arguments

-v = verbose mode
length = length of drift scan [arcsec]

Output

Restrictions

- Slit must be oriented N/S so that drift scanning is purely E/W.
- Guide star should be at least 0.5*length arcsec from edge of pickoff mirror
so that it is not lost during offset

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