The program you're referring to is probably Brian's TA (Terrain
Analysis). It gives you the antenna pattern over an arbitrarily shaped
ground -- I've used it for many years in choosing Field Day antenna
locations. It's a DOS program, but I don't know of any more recent
program that does the same thing. I believe Brian will still sell it if
you contact him by mail at his Callbook address.

TA requires as its input a free-space pattern in the OpenPF format he
devised (with some help and advice from me). EZNEC and Brian's analysis
programs like AO produce plot files in that format. It's thoroughly
documented in the EZNEC manual, so it wouldn't be difficult for someone
with minimal to moderate programming skills to convert files of other
formats to OpenPF for use by TA.

For the OP, though, if the ground is simply constantly sloping for a
long distance, do as suggested -- tilt the antenna in the model. Then
tilt the resulting pattern in the opposite direction to see the result.

Roy Lewallen, W7EL

Jim - NN7K wrote:
Think Brian, K6STI used to advertize a program modeled over
TRUE ground (like topo map, ect). Dont know if he still
sells it, however. (That for antenna patterning , H.A.A.T.)
As info, Jim NN7K

Alex AG0Z wrote:

I have thanks. I'm just not sure of the elevation results.