What's underneath the crawl? Copper pipes? metal/wood frame? Anything that could be grounded to? At one time they allowed us to ground to an air-conditioning unit frame. But they changed that because the frames aren't always backbonded to the house ground.
When people mount their dish in the yard, most of the time an installer has done it and has used the RG6 Dual w/ground. We're required to ground it. Part of our job when we pull up on a house is to do a site survey with the customer, going over mounting options, grounding points, entrance points etc etc. My optimum install for me personally, if I can enter the house through a basement wall through the sill or bandboard, near the electrial breaker panel if it all possible then put my ground-block right next to it and ground right to the house ground coming off the top of the panel with a split bolt. They want us to put our ground-block outside, but the way I see it, the less exposed connections you have, the better off you'll be in the long run. I tell my sup this, and as long as he knows exactly what I've done when he goes to QC me he won't fail me on that job.
Quick question, why are you wanting to do all this on your own?