Intro to the field - and Background information on photogrammetry using drones -- Photogrammetry Software For Professional Drone Pilots 12 Best Photogrammetry Software For 3D Mapping Using Drones | DroneZon (more detail - professional discussion) Drones are flown in a pattern recorded by the on-board GPS receiver and the data. w/video downloaded. A 3D image or map is developed by the program. If using a drone mounted LiDAR, an output that looks very much like an SAR (Synthetic Aperture Radar) is obtained at a fraction of the cost and computing power. used by SAR systems. I post this to add some context for my upcoming trip to the CCC Swales. My brother (the one with Dr in front of his name) is retiring and one of the irons he has in the fire is teaching GIS with/using drones. So mapping the swales will allow for some real world data for use in his classes....and some fun for the both of us. I'll be focusing on the water flow around the swales and the flow patterns when the 'reservoir behind the swale' is fulled. As an aside, the power of current scientific instrumentation is simply astounding. "The current standard for sensitive gravimeters are the superconducting gravimeters, which operate by suspending a superconducting niobium sphere in an extremely stable magnetic field; the current required to generate the magnetic field that suspends the niobium sphere is proportional to the strength of the Earth's gravitational acceleration. The superconducting gravimeter achieves sensitivities of 10–11 m·s−2 (one nanogal), approximately one trillionth (10−12) of the Earth surface gravity. In a demonstration of the sensitivity of the superconducting gravimeter, Virtanen (2006), describes how an instrument at Metsähovi, Finland, detected the gradual increase in surface gravity as workmen cleared snow from its laboratory roof. The future is here.