This parameter selects the type of line fit for blaze function fitting.
The available functions are POLY (the default), MEDIAN and SPLINE.
Note that the required maximum number of coefficients is different in each case. For POLY the maximum number of coefficients corres ponds to the number of degrees plus one, so for a cubic use coeffs=4. For a SPLINE the maximum number of coefficients corresponds to (knots+7)*2, so for 3 knots use coeffs=20. If you are using SPLINE fits then you should ensure that the value of TUNE_MAXPOLY is set accordingly, as well as using an appropriate value for BLZ_NPOLY.
When MEDIAN is selected local medians of X-extent BLZ_NPOLY pixels are used as the blaze function.
INITIAL SUGGESTED VALUE: POLY.
Martin Clayton