How to produce digital elevation models?

Jul 17, 2023

There are three main types of data acquisition:

1) Measurement directly from the ground, such as GPS, total station, field measurement, etc.;

2) According to the aerial or space images, through the photogrammetric way, such as stereo coordinate observation and space-three encryption, analytical mapping, digital photogrammetry, etc.;

3) Collect data from existing topographic maps, such as grid reading method, digitizer manual tracking and semi-automatic collection by scanner, and then generate DEM through interpolation.

How to obtain higher precision DEM?

With the data of several high-resolution satellites as the original data, the directional points with 3D coordinates obtained by aerial triangulation and solved by strict adjustment constitute a triangulation network to generate a digital surface model, and then process and produce a 5m/10m spatial resolution digital elevation model (DEM) through intelligent human-computer interaction means such as filtering and editing.

At present, by using high-precision DEM data, GIS and hydrology methods, Feiyan Remote Sensing can finally determine the distribution range of water-prone areas in urban built-up areas through flow direction calculation, depression point data extraction, depression contribution area extraction, depression depth calculation and accuracy evaluation.