MAP_CONVOLUTION Integer
Select the desired convolution function for gridding in the UV plane
Choices are
0 Default (currently 5)
1 Boxcar
2 Gaussian
3 Sin(x)/x
4 Gaussian * Sin(x)/x
5 Spheroidal
Spheroidal functions is the optimal choice. So we strongly discourage
use of any other convolution function, which are here for tests only.