In this video I built a few solar panel mounts for my workshop. This mount would work for both a flat roof, or installing on the ground. If installing this on the ground it would just need to be staked down, or bolted to a concrete pad to hold it in place.

This was built using all 1/8" thick aluminum angle, most was 1" with some parts using 1 1/2" angle. If you are considering this project I would definitely recommend looking for a local metals supplier and getting quotes from more than one if possible to get the best price. Comparing prices from the supplier I used the local big box hardware store prices were four times the price I paid. They also only had lengths up to 8' where the supplier sold full lengths of 25' angle which would could cut down on waist from small un-usable scrap parts.

Parts and tools used
1/8" X 1" aluminum angle
1/8" X 1 1/2" aluminum angle
1/4" nuts, bolts, washers
3/8" lag bolts

Milwaukee Cordless Drill https://amzn.to/2KYFTQG
Milwaukee Impact Driver https://amzn.to/35XzNJY
Eastwood horizontal band saw https://amzn.to/3dprQ2Z
HQST 100 Watt solar panels https://amzn.to/3e7mdq5