Observing with MODS

MODS1+MODS2 binocular observing is now supported for MOS, long-slit and imaging observations of the same target and using the same PA and guide star. The two options supported at this time are:
  1. Identical Twinning (the same script on both sides)
  2. Fraternal Twinning (same base configuration but different scripts, e.g. the same base position, position angle and guide star but different MOS masks or different configurations on each side (a 1″ long-slit observation using MODS1 blue-only acquisition and spectroscopy and MODS2 red-only acquisition and spectroscopy.

The following sections provide details on running the instrument, taking and checking data, and the appropriate calibrations needed .

The sections outlined are:

                  Quick Review - One page review of MODS1+MODS2 setup and observing.
Observing Commands - Describes the commands that are used to operate the instrument.  Understanding and utilizing these commands are needed to proceed with observing.
Instrument Setup - Outlining how to setupMODS1 and/or MODS2 for nightly observing.
Monocular Observing - Outlining how to observe with MODS1 or MODS2.
Binocular Observing - Outlining how to observe with both MODS1 and MODS2 simultaneously.
Quick Reduce - Describes a method for a quick look at MODS1 data  as it comes in so observers can confirm quality of data. The quicklook reduction is not yet available for MODS2.
Calibrations - Outlines the calibrations needed for Long-slit, Multi-Slit, and imaging modes.  Further detail is provided in a sub page.
Troubleshooting - Common gotcha's and faults are outlined with their solutions.

Operations Overview

  1. In the afternoon prior to observing, from an OBS machine start MODS software. Wake MODS, and take a test image.

  2. Script engines are used to send the scripts. The commands used to run scripts, center objects on the slits or align masks, display images and check the status of or start/stop services are listed below with a brief description of their function. Monocular script engines (require a --mods# flag) and binocular script engines exist.  There are several programs to execute scripts: 
    1. acqMODS or acqBinoMODS object acquisition scripts 
    2. execMODS or execBinoMODS to run spectroscopic and imaging scripts. 
    3. Spectroscopic object acquisition uses the script modsAlign.

  3. End of night, put MODS to sleep and the software.