Aerial Triangulation (AT) or aero triangulation is the process of contiguous densifying and extending ground control through computational means. It is a very crucial part prior to produce any photogrammetric products, like DTM, DSM, Orthophoto etc., from stereo Images. There are several sophisticated steps for this operation like performing interior orientation; Automatic and/or manual tie point generation; establishing ground control points; and performing a least squares block adjustment etc. The purpose of Aerial Triangulation is to refine the Exterior Orientation parameters (ΔX, ΔY, ΔZ, Ω, Φ, κ) computed through direct geo-referencing for each Imagery, which will help to achieve the desired accuracy while generating DEM, Orthophoto and other photogrammetric products.
In general, Aerial Images with Initial Exterior Orientation (EO), ground control points (GCP) and Interior Orientation (IO) provided by client will be used for AT process. We, the highly experienced team of Grameentech, follow the latest and high-end aero triangulation approach that minimizes the manual intervention and increases accuracy towards higher side. This is the combination of point selection, point measurement, point transfer and block adjustment in a single process.