Test Results Using the DTM Software of PCI

Transcription

1 M. Schlüter, B.-S. Schulz, C. Wende Test Results Using the DTM Software of PCI Bundesamt für Kartographie und Geodäsie Richard-Strauss-Allee Frankfurt (Main) Internet:

2 Overview 1. Introduction: Versions of EASI/PACE, basic concepts 2. DTM Reconstruction: Process flow and computation times 3. DTM Reconstruction: Results from testsite Vaihingen (Enz), comparison with reference data 4. Conclusions Test results using the DTM software of PCI 1.1

3 DTM Generation using PCI-software We refer to: PACE Airphoto DEM Package Versions: EASI/PACE 6.0 (=15th version) and EASI/PACE We do not refer to: PCI OrthoEngine (PCI, 3. 98: software guided DTM generation; block bundle adjustment; elevation data interpolated directly from points, contours, breaklines and TINs; 2-d and 3-d DEM editing tools,... ) : Test results using the DTM software of PCI 1.2

4 GUI - Example: Measurement of Fiducial Marks Test results using the DTM software of PCI 1.3

5 Operator Machine? DTM Generation: Preprocessing Task: PCI-modul: Amount of time: [min:] Data conversion CIM, IMAGERD 15 Conversion of distortion CALDIST 5 Interior orientation PPOINT 15 Measurement of control points GCP-Works Exterior orientation CAMERA 2 Calculation of an epipolar image 60m : AEPIPRO 2 : 8 30m : 32 15m? DEC Alpha , 64bit processor, 275MHz, 128MB RAM Test results using the DTM software of PCI 2.1

6 mode 60m 30m 15m DTM Generation and Postprocessing Task: PCI module, Computation time? :[min:] DTM generation ADEM coarse medium fine Geocoding ADEMCPY Geocoding & interpolation ? DEC Alpha , 64bit processor, 275MHz, 128MB RAM Test results using the DTM software of PCI 2.2

7 Here, one might expect more... Interior orientation: only2-4fiducialmarkspossible, no subpixel accuracy, distortion only by the radial polynomial d(r) = a 1 r + a 2 r 3 + a 3 r 5 + a 4 r 7 Exterior orientation: separate orientation of each single image Accuracy of parameters: Residuals are often given, but standard deviations are usually missing User s knowledge about accuracy is presumed! ( ) DTM generation, geocoding & interpolation: Poor documentation meets sometimes strange results, user has to manage short int (16Bit) elevation data, amount of disk space is more than 3 image data Test results using the DTM software of PCI 2.3

8 Visual Check of Epipolar Image Calculation (Basis for the Choice of an Evaluation Area) Test results using the DTM software of PCI 3.1

9 Results of the Matching Procedure ( fine ) with Interpolation Left image (= reference) Geometric result from 60 60m 2 image pixels Geometric result from 15 15m 2 image pixels Test results using the DTM software of PCI 3.2

10 Results after Geocoding with Interpolation Geometric result from 60 60m 2 image pixels Geometric result from 15 15m 2 image pixels Test results using the DTM software of PCI 3.3

11 Classification (ifp) Height Differences: jz PCI, Z ifp j (60 60m 2 image pixels) (15 15m 2 image pixels) land use vegetation (height) roughness texture 0, 0:2m 0:2m, 1m 1m, 2m 2m, 5m 5m, 20m no reference data Test results using the DTM software of PCI 3.4

12 Conclusions Main intentions of PACE Airphoto DEM Package: Production of single orthoimages Focus on small & medium image scales (remote sensing!) + No unnecessary burden of decision making Very limited self-diagnosis, missing accuracy statements, Z = 2 pixel size on ground) ( No documentation concerning matching & interpolation, algorithms and assumptions Some pitfalls (intermediate storage of matching result, using short int data type, e.g.) Test results using the DTM software of PCI 4.1

13 How to Overcome Problems? Actual publications on multi-image matching in object space from the Institute of Photogrammetry and Cartography, Darmstadt University of Technology: M. Schlüter und B.P. Wrobel: Das Dezimeter-DGM durch photogrammetrische Oberflächenrekonstruktion mit dem Facetten-Stereosehen, AVN, September 1998 M. Schlüter: Multi-image matching in object space on the basis of a general 3-d surface model instead of common 2.5-d surface models and its application for urban scenes, ISPRS Commission IV Symposium, Stuttgart, September 7-10, 1998 Next workshop on multi-image matching? Test results using the DTM software of PCI 4.2