Exposition Time Calculator for Spectroscopy

This exposure calculator predicts the signal-to-noise ratio achieved with DOLORES or NICS for a given exposure time and observing conditions. If sky brightness is not entered, the program uses the default values (new moon for DOLORES).
To run the program enter values below and click on 'Submit'. You may set signal-to-noise and obtain the corresponding exposure time, or viceversa.

Note the javascript option on your browser should be activated for the exposure time calculator to work properly.

Instrument Grism
Source Type NICS FOV
Fwhm   arcsec Slit width
Air Mass Sky Brightness Days from new Moon: 
Apparent Magnitude mag (mag/arcsec² if extended) Band
  Exposure Time seconds   Signal-To-Noise