Use a simple 2D polynomial fit of sin(HA) and Dec to predict the field rotation rate
This replaces the physical model which was not accurate enough. The fit is based on a data set provided by Santiago Serrano.
The PR includes the data, the script to fit the polynomial, and the new function with hardcoded polynomial coefficients. The interface is not modified.
The rms of the residuals to the best fit model is of 0.11arcsec /min, which, for a 20 min exposure, corresponds to a drift of 0.6 arcsec for a star on the edge of the field. This rms is consistent with the statistical uncertainties reported in the data file.
Use a simple 2D polynomial fit of sin(HA) and Dec to predict the field rotation rate
This replaces the physical model which was not accurate enough. The fit is based on a data set provided by Santiago Serrano. The PR includes the data, the script to fit the polynomial, and the new function with hardcoded polynomial coefficients. The interface is not modified.
The rms of the residuals to the best fit model is of 0.11arcsec /min, which, for a 20 min exposure, corresponds to a drift of 0.6 arcsec for a star on the edge of the field. This rms is consistent with the statistical uncertainties reported in the data file.