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13 th International Scientific and Technical Conference From Imagery to Map: Digital Photogrammetric Technologies. Scientific UAS training for mapping Smirnov Alexey Manager of Technical Support Department , Racurs. September 20 13 , Fontainebleau, France. Scientific training area MIIGAiK.
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13th International Scientific and Technical Conference From Imagery to Map: Digital Photogrammetric Technologies Scientific UAS training for mapping Smirnov Alexey Manager of Technical Support Department, Racurs September 2013, Fontainebleau, France
Scientific training area MIIGAiK June 2013 Department of photogrammetry
UAS Models Ptero-E5 Gatewing X100 GeoScan 101
Objectives • Process Ptero UAS imagery with high-precision projection centers coordinates • Compare accuracy of adjustment for Ptero data over small area vs whole block • Compare accuracy of adjustment results from different UAS models
Technological workflow Aerotriangulation DEM Orthophoto control
Objects Area 4 sq.km. Road 5 km.
Testing with accurate centers (Ptero) * GPS position adjustment accuracy (using Obninsk base station) is 6 cm * By GNSS+ company
Spatial offset Offset vector : x=0.047 m, y=0.110 m, z=0.194 m
Time offset NovAtel OEM615 Nikon D800 Synchronization problem is caused by two-curtain shutter
Adjustment result by centers Errors Projection Centers ~30 cm by XY ~20 cm by Z Check points ~33 cm by XY ~34 cm by Z GCD – 2 cm
Adjustment result by centers and GCPs Errors Projection Centers ~30 cm by XY ~16 cm by Z Check points ~16 cm by XY ~16 cm by Z GCD – 2 cm
Orthophoto quality GSD – 2 cm
Orthophoto accuracy (relative) Vectors from stereo of DiMAC survey Positional accuracy Δ~ 18 cm
Orthophoto accuracy (absolute) Eabs Δmin. – 6 cm Δmax. – 16 cm Accuracy corresponds to scale 1:2000
Small test area (Ptero) Errors Projection Centers ~17 cm by XY ~10 cm by Z Check points ~7 cm by XY ~9 cm by Z
Small test area (Ptero) Eabs Δmin. – 2 cm Δmax. – 7 cm Accuracy corresponds to scale 1:1000
Small test area (GeoScan) Errors Projection Centers ~3 m by XY ~16 m by Z Check points ~22 cm by XY ~30 cm by Z GSD – 7.2 cm
Small test area (GeoScan) Eabs Δmin. – 13 cm Δmax. – 23 cm Accuracy corresponds to scale 1:2000
Small test area (Gatewing) Errors Projection Centers ~7.5 m by XY ~20 m by Z Check points ~6 cm by XY ~18 cm by Z GSD – 4.7 cm
Small test area (Gatewing) Eabs Δmin. – 14 cm Δmax. – 22 cm Accuracy corresponds to scale 1:2000
Conclusions • Prerequisites for obtaining large scale orthophoto • Use differential GNSS for projection centers coordinates • Avoid large heading-pitch-roll angles • Use appropriate ground control • Use appropriate GSD • Use calibrated camera