1. THE USE OF REMOTE SENSING IMAGERY FOR CREATING DIGITAL TERRAIN MODELS AND VISUAL 3-D VIEW
Raad A. Kattan(1) * , Abdurrahman Farsat Heeto**(2) , Hussein H.Hassan(3)
(1)University of Duhok, College of Engineering, Department of civil Engineering.
(2)University of Duhok, College of Engineering, Department of water resources.
(3)University of Duhok, College of applied science, Department of Planning.
The University of Duhok
Source of Images
Satellite imagery from ESRI (Environmental Systems Research Institute)
Aerial photo from voicing German company.
Google Erath
Terrestrial images (close range photogrammetry)
Summary
Digital terrain models and topographic maps can be generated using pairs of satellite images. For this purpose images should be acquired to the same spot from two satellite positions. Intersecting rays provide the solution. Spot satellite can provide such oblique pairs of images. However these images are not readily available and if so they are rather expensive.
The acquisition of different images taken by different satellites or using aerial platform to the same ground spot is not so difficult. On examining such images it is obvious that the relief displacement and direction is not identical as images are taken from different satellite at different view angles. This means that intersecting rays can be created and bundle solution can be achieved.
The objective of this work is to generate a digital terrain model using pairs of aerial and satellite images to the same ground spot and creating a 3-D visual model that show the ground topography. Automatic matching technique between pixels on different images is the first step in this solution.
Ground control points on the area of study are collected using the Leica Viva DGPS system.
Point cloud
Mesh wireframe
3D Model
Digital Terrain Model (DTM)
Orthophoto and DEM generation with GCPs using Agisoft PhotoScan
WORK PLAN
1- Data collection for ground control points using Leica viva DGPS
2- Create Contour map and mesh wireframe surface from the collected data using AutoCAD civil 3D and ArcGIS
3. Create Orthophoto and DEM generation with GCPs using Agisoft Photoscan
4 Examining the ability of using terrestrial images to create Orthophoto and DEM of a part of study area and is in progress
3- Compare the created point cloud with Surfer V8 created Surface
Point cloud
Mesh wireframe
3D model
Label
X error (m)
Y error (m)
Z error (m)
Error(xyz)(m)
Overlap images
Error (pix) 1 4 2 3 5
Discrepancy of checking Control points
ArcGIS three dimensional relief view
3D relief without images
The coordinates of the Reference point
Lieca GPS (GS10 and GS15)
3D relief Histogram
Analysis of surveying data
DEM overlain area of interest
Conclusion
The positioning accuracy of the GPS system is a critical part in the error budget and thus ground reference data is needed.
Using GCPs can minimise matching error of different images.
The geo-referenced of the different sources of data can provide more accurate result than using one source. Up to 0.08 m position can be achieved in urban canyon.
The accuracy of matching different images increases with an increased number of control points. The more the number of control points, the better the accuracy that can be achieved.
The quality of matching different images can be further improved in terms of details and accuracy by including terrestrial images in the matching process.
Contour Map
Mesh wireframe
3D Surface
After removing outlier
Residuals between observed data and reconstructed surface
Acknowledgement
The authors would like to thank University of Duhok, College of Engineering for their support.
Vector map overlain shaded relief map
Presented at: ISPRS Hannover Workshop 2009
WG I/2, I/4, IV/2, IV/3, VII/2
High-Resolution Earth Imaging for Geospatial Information
Hannover, Germany
June 2-5, 2009
The University of Duhok
Will be presented at: RSPSoc2015-Annual Conference
Southampton University, UK
September 7-11, 2015