Experimental aerial photogrammetry with professional non metric camera

Experimental aerial photogrammetry with professional non metric camera Canon EOS 5 D Galileo Geo Sustavi Ante Sladojević, Goran Mrvoš

Content • • Introduction Project Specification Camera Calibration Flight plan Aerotriangulation Creating DEM and digital orthophoto Conclusion

Introduction • • • Test professional non metric camera Aerial photogrammetry purpose Will it work in aerial photogrammetry? Reliability? Accuracy?

Project specification - equipment • Camera Canon EOS 5 D • • • Sensor type • • Image size: Dimensions: • • 35. 8 x 23. 9 mm CMOS 12. 8 million effective pixels 4368 x 2912 pix 152 x 113 x 75 mm Wide angle lens (24 mm) Camera box and carrier Airplane Cessna 172 Rocket PHOTOMOD 4. 1

Project specification - work flow • • • Camera calibration Making flight plan Flying and taking images of selected area Loading images in photomod, aerotriangulation Creation of DEM and digital orthophoto Analyzing results

Camera Calibration • • • Lens (24 mm) Characteristics of a camera (focal length, lens distortion) Used software Photo. Modeler pro 5. 0. 2 D dimensions calibration grid Results of camera calibration: • Focal Length - Value: 23. 811862 mm • Principal point (Xp, Yp) • (17. 311063 mm, 11. 615114 mm) • Radial distortion (K 1, K 2 , K 3) • Decentering distortion (P 1, P 2)

Flight plan • Area = 2. 2 km long (city highway) • Two strips (52 images) • Base 120 m (60%) • Distance between strips 310 m (30%) • Flying height (300 m) • Scale 1: 12500 • Navigation with Garmin GPS

Aerotriangulation • PHOTOMOD 4. 1 (default configuration) • Automatic aerotriangulation (1272 tie points) • Correlation (>0. 94, parallax <0. 010 mm) • • • 10 GCP, 4 beginning and GCP residuals Xm-Xg mean absolute 0. 038 RMS 0. 046 Maximum 0. 087 the end of the strips, 2 in the middle of the strips Ym-Yg 0. 045 0. 053 0. 102 Zm-Zg 0. 160 0. 184 0. 316 Exy (m) 0. 062 0. 070 0. 134

Creating DEM and digital orthophoto • • • DEM (1 m) Vectors and breaklines (Stereo Restitution, PHOTOMOD Stereo. Draw) Digital othophoto (PHOTOMOD Mosaic) Geometric resolution (0. 1 m) Digital orthophoto control: • • Overlap with exisiting data The results were very good - max overlap error was 0. 4 m.

Conclusion • Good accuracy • Large number of images for small areas (1 km=10 images) • Not good for large areas (time) • Digital non metric camera are getting better and better (16 Mpix, 32 Mpix) • Better accuracy's • Better resolution (good calibration)

Thank you for your attention ! • Questions?