Perhaps you already know about this but for the last year or more I have used 'The Claw' to tie down the tripod - it is fantastic. It is available at:
www.creativeshelters.com/Canopy-Accessories/The-Claw-Anchor.aspxBasically it has three prongs secured into the ground with long spikes and is most often used to tie down aircraft - it will hold 1200 lbs. I doubt any strong wind could pull the Claw out and thus move the satellite dish. The cost is $19.95 US plus shipping.
Anyone got a great idea for a tie down when mounting the tripod on pavement where you cannot drive spikes into the pavement? The best I have come up with is using several water jugs or refillable water bladders.