Using inexpensive drones and photogrammetry to stitch lots of photos together is fairly straightforward these days: https://www.mobiddiction.com.au/drone-mappi

Using inexpensive drones and photogrammetry to stitch lots of photos together is fairly straightforward these days: https://www.mobiddiction.com.au/drone-mapping-in-4-steps/ https://www.mobiddiction.com.au/drone-mapping-in-4-steps/ Depends a lot on what you mean by "site survey" though. The photogrammetry used there also created a depth map from the stereography where images overlap: https://www.mobiddiction.com.au/wp-content/uploads/2019/11/Team_Photo_5._V2.jpg https://www.mobiddiction.com.au/wp-content/uploads/2019/11/T... You can see in the bottom right corner of that the elevation changes for the roundabout and the ~120mm high curbs at the edges of the roads - and the gradual slope of the whole site towards the top right corner. (There's a lot more detail and calibration data than that image shows in the full data set there.)