Greg, The first point is part of the header bytes 21-23 & 24-26 The corner points of the image are: lat 23 lon -120 lat 47.2634 lon -63.5664 The FNEXRAD data type has been around for a long time, but if your LDM is very onld version 5, you may use NMC3 as the feedtype. But.....upgrade to current LDM6 when possible to get the best perfomance. Steve Chiswell