This form estimates the Signal to Noise Ratio (SNR) for aperture photometry of a point source. The SNR is calculated for a V band observation using the properties of the sensor (CCD), instrument (telescope and filter), and the observation itself. Use this calculator to plan observations by estimating the effect of exposure time and other parameters. You also can work backward to determine what combination of parameters gives a target SNR.
This form calculates the Magnitude Error or Signal to Noise Ratio (SNR) as a function of radius for aperture photometry of a point source. Use it for estimating the optimal measuring aperture radius or estimating the loss of precision from using a non-optimal aperture radius. This tool calculates results for a single aperture but makes a plot over a range of aperture radius.
This form creates a table of airmass and hour angle for one time or a range of time. Use it for planning observations. The format of the coordinate, date, and time fields is relaxed in allowing separators from the list "- /,:dhms", including the space character.
4. Astronomical Airmass Planner (with discrete time, date, and coordinate fields)
This form creates a table of airmass and hour angle over a range of time. Both begin and end, as well as the reporting interval are required. Use it for planning observations.