I did a little searching around and found
this. Look at the answer to FAQ #21 - it has a free program you download and install, enter your location and it gives you azimuth and elevation of all the C band and Ku band satellites. DirecTv uses the Ku satellites.
I know nothing about this web site, but I have about every possible safeguard installed on my laptop and it didn't raise any red flags when I downloaded and installed their program. Have to be careful about downloading stuff like that, but this looks OK...
Wagonmaster2 - I don't see any reason you can't receive the other Ku satellites with your rooftop unit - just a matter of finding them. I guess the tricky part is knowing which channels are on which satellite, but maybe you already know that.