DOWNSAMPSCALE

Speeds up map-making, and reduces memory requirements

Description:

If the telescope is scanning slowly the data may be safely down-sampled to save memory and time. This parameter controls the minimum angular scale on the sky. The new sample frequency is chosen such that this scale will be preserved taking into account the average slew speed and the sample rate of the input files. If a positive value is selected, this gives the angular scale (in arcsec) to which the new sample rate will be matched. Alternatively, if a negative value is supplied, its magnitude will be multiplied by the PIXSIZE for the requested map. For example, the default here is to set it to -1 such that the time-series sample rate matches the pixel grid (in practice, a factor of 2 might make more sense as this would correspond to the Nyquist frequency of the map pixel grid). [-1]
Type:
real

SMURF Usage

MAKEMAP, CALCQU