Abstract : Digital Elevation Models (DEMs) are commonly
produced through different surveying approaches that varied
in processing techniques, time, and cost. During the last
decade, the Global DEMs of the Shuttle Radar Topography
Mission (SRTM) with a horizontal resolution of 90 m is
representing the freely available DEMs worldwide with
relevant quality. The main objective of this research is to
improve the accuracy of the DEM generated by SRTM using
GPS data fusion and a developed regression model. Ground
control points (GCP) were observed using GPS with
centimetre-level accuracy. Herein, the GCP are divided into
two main groups. The first group is the solution dataset that
define the coefficients of the polynomial, while the behaviour
of the polynomial has been investigated against the number
of used common points and the average spacing between
these points. The second group is a check dataset which is
used to assess the accuracy of the new developed DEM using
statistical methods. Moreover, the potential of using visual
analysis technique has been proved by the evaluation of the
validity of the visual techniques in doing such analysis. The
final analysis results has shown that the applied polynomial
of the first order using control points with average spacing
250 m has improved the SRTM DEM to be more close to the
GPS DEM. Also, the statistical analysis has supported these
results where the value of the root mean square error
(RMSE) of the check points is ranging between ±0.42 m and
±1.21 m for flat terrain. |
