The highest precision available. LiDAR stands for Light Detection and Ranging. It's a technology that uses laser light pulses to measure distances. LiDAR can calculate the distance to the ground or any object on it with very high precision. It's particularly effective in heavily vegetated contexts. (where a photogrammetry approach can fall short of capturing land data beneath foliage)

High precision. This is achieved by taking many aerial photographs of the area, (each photo is geolocated) and then 'tying them together' using specialized software.

'Control points' can be used to increase precision. This involves numbered markers fixed onto the ground before the drone flight so that the markers appear in the photos. The markers are geolocated on-site using GNSS technology (Altitude, longitude, latitude) which optimizes the overall precision once images are 'tied' together.

Moderately precision. This is achieved by taking many aerial photographs of the area, (each photo is geolocated) and then 'tying them together' using specialized software. This gives us the landform (topography)

A survey like this without control points delivers moderately accurate results, perfectly suitable for many contexts.

This method involves a man on the ground taking specific 'point' data with specialized equipment. In some cases, a rover (vehicle) may be implemented. 

The technique delivers high precision- but only at the exact point where a measurement was taken. The rest of the information is interpolated. (The more points taken, the more accurate the topography).

This approach is typically suitable for small-scale contexts, due to the human labor and time required.