COMPARISON OF THE ADVANCED LAND OBSERVING SATELLITE (ALOS) DATA TO THE LIGHT DETECTION AND RAGING (LIDAR) DATA, SHUTTLE RADAR TOPOGRAPHY MISSION (SRTM) DATA, AND THE SYNTHETIC APERTURE RADAR (SAR) DATA FOR THE PHILIPPINES' DREAM/PHIL-LIDAR1 PROGRAM

摘要

The Light Detection and Ranging (LiDAR) derived Digital Elevation Models (DEMs) produced by the UP DREAM Program are used to produce the up-to-date hazard maps of the major river basins in the Philippines. These DEMs are used to produce the flood models of the river basins. However, several unavoidable data gaps can be found in the DEMs because of two major reasons: (1) the varying cloud cover in the areas when the plane is flying, and (2) the varying terrain of the areas which makes it difficult to easily change the altitude of the plane. As a result, the major river basins are not fully covered because of the several no data patches found. This paper presents the results of the accuracy assessments done to determine which geospatial dataset can be integrated into the LiDAR data to fully cover the river basin areas. Several accuracy assessments were done into the following spatial datasets: Shuttle radar Topography Mission (SRTM), Advanced Land Observing Satellite (ALOS), and the Synthetic Aperture Radar (SAR) data. The SRTM and ALOS are both open source geospatial datasets. Three accuracy assessments were done: vertical accuracy assessment using field validation points, Histogram Profiling, and the Drainage production assessment. The overall vertical accuracy shows RMS error of 3. 48 m, 1.92 m, and 1.96 m for SRTM, ALOS, and SAR respectively, when compared with the LiDAR DEM. The vertical accuracy also shows a Standard Deviation of 3.45 m, 1.92 m, and 1.91 m for SRTM, ALOS, and SAR respectively. The slope and profile of the DEMs are also affected by the difference in spatial resolution. Thus affecting the drainage network delineation for the study area. These results can serve as a basis for selecting which DEM can be integrated into the LiDAR data.