From Imagery to Map: Digital Photogrammetric Technologies 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 2013, Fontainebleau, France

Scientific training area MIIGAiK Department of photogrammetry June 2013

UAS Models GeoScan 101Gatewing X100 Ptero-E5

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 Orthophoto control DEMAerotriangulation

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 Nikon D800NovAtel OEM615 Synchronization problem is caused by two-curtain shutter

Adjustment result by centers Errors Projection Centers ~30 cm by XY Check points ~33 cm by XY ~20 cm by Z ~34 cm by Z GCD – 2 cm

Adjustment result by centers and GCPs Errors Projection Centers ~30 cm by XY Check points ~16 cm by XY ~16 cm by Z GCD – 2 cm

Orthophoto quality GSD – 2 cm

Orthophoto accuracy (relative) Positional accuracy Δ ~ 18 cm Vectors from stereo of DiMAC survey

Orthophoto accuracy (absolute) E abs Δmin. – 6 cm Δmax. – 16 cm Accuracy corresponds to scale 1:2000

Small test area (Ptero) Errors Projection Centers ~17 cm by XY Check points ~7 cm by XY ~10 cm by Z ~9 cm by Z

Small test area (Ptero) E abs Δmin. – 2 cm Δmax. – 7 cm Accuracy corresponds to scale 1:1000

Small test area (GeoScan) Errors Projection Centers ~3 m by XY Check points ~22 cm by XY ~16 m by Z ~30 cm by Z GSD – 7.2 cm

Small test area (GeoScan) E abs Δmin. – 13 cm Δmax. – 23 cm Accuracy corresponds to scale 1:2000

Small test area (Gatewing) Errors Projection Centers ~7.5 m by XY Check points ~6 cm by XY ~20 m by Z ~18 cm by Z GSD – 4.7 cm

Small test area (Gatewing) E abs Δmin. – 14 cm Δmax. – 22 cm Accuracy corresponds to scale 1:2000

Difference ModelsCamera altitude, m Number of frames Area, sq.m. Centers accuracy Orthophoto accuracy (absolute), cm GSD, cm/pix Ptero-E5 Nikon D800 (calibrated) ~ ~17 cm by XY ~10 cm by Z GeoScan 101 Sony NEX- 5R ~ ~3 m by XY ~16 m by Z Gatewing X100 Ricoh-GR ~ ~7.5 m by XY ~20 m by Z

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

Thank you for attention