At the processing stage of the DREAM workflow, several useful products are generated. These include digital terrain models, digital surface models, and orthophotos. Below are sample data on the Buayan River Basin. The DTMs and DSMs are in .tif format and need to be viewed using GIS software. To access these data sets, please lodge a request in LiPAD, the DREAM/Phil-LiDAR data portal. For questions, email firstname.lastname@example.org.
Classified LAS files are pointcloud data categorized as buildings, streets, and other above-ground structures using TerraScan.
Digital Terrain Model (DTM)
The digital terrain model, or the DTM, is a three-dimensional illustration of a terrain surface. As such, it is also known as the “bare Earth” model. Aside from elevation data, the DTM also represents geographical features central to the mapping and modeling objectives of the Program. This includes rivers and ridge lines, among others.
Among the common uses of DTMs are water flow or mass movement modeling, terrain parameters extraction, relief maps creations, and terrain analyses.
Download sample DTM:
Digital Surface Model (DSM)
Unlike the DTM, the digital surface model (DSM) also represents the MSL elevations of surfaces above the “bare earth,” like buildings and trees. Basically, the DSM is the DTM with the reflective surfaces. It has the same applications as the DTM.
Apart from the elevation models, the UP DREAM Program also captures aerial photographs during its LiDAR data acquisition. These images are corrected to position features on their geographic coordinates. The end-product for this process are detailed, accurate, and high-resolution orthoimages, which are particularly useful in geospatial analyses.
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