Quality Accuracy Professionalism

Transcription

1 GeoWing - who are we? Mapping Data Service Provider Lidar Multispectral Topographic and Planimetric Maps Elevation Models Point Clouds / 3D Models Orthophotography FAA-Authorized UAS Operators WOSB / DBE Professional Engineer, Surveyors, Certified Photogrammetrists, GIS Analysts Quality Accuracy Professionalism

2 Overview Background GeoWing UAV Specifications Project Area Data acquisition Processing and results Assessing the accuracy of results Conclusion

3 Technical Innovations Development of Photogrammetry Digital Analytical Analog Plane Table present Photography Aeroplane Computer CCD-Camera UAV (Ahamed, Historical Development of Photogrammetry)

4 UAV reshaping the mapping industry High Resolution Products Recognize New Quality Standards Low Cost Platform Generous conditions for data acquisition Lower Altitude Higher Resolution Lower Cost photogrammetric platform Revised ASPRS standards (2015): map scale/contour scale to GSD (digital) Deploy in better mobility and logistics under overcast condition under a prompt request

5 Conventional or New Photogrammetry Purpose: to examine data quality and data processing requirements for each approach Mapping applications are accuracy sensitive UAV as a low cost photogrammetric platform Data Acquisition Expected Results Examples

6 GeoWing UAV Specification Make BirdsEyeView Aerobotics Model FireFLY6 Endurance 45 min Payload 2.5 lbs. Data Link 900 Mhz Website: General Description FireFLY6 provides a multicopter configuration on a fixed wing UAV providing advantages of taking-off and landing vertically, and hovering and maneuvering like a multicopter, while providing the long endurance advantage of a fixed wing. It has a cruise speed of 34-40mph and max speed of 65mph..

7 Project Area and Collection Time Location: Las Positas College, Livermore acre Flight Date/Time: October longer shadow Acquisition Date Flight Duration Manned Aircraft UAV 2015/10/ /07/16 Less than 11 min in 34 min (1:39~:40, 1:43, 1:48, 1:50, 1:55~:56,1:58, 2:03~ 2:04, 2:13 pm) 17 min (3:56~4:13 pm)

8 Data Acquisition 960 m 100 m Camera # of Images Manned Aircraft Canon EOS 5DS R focal length 85 mm 8688 x 5792, 72 dpi UAV SONY ILCE-5100 focal length 16 mm 6000 x 4000, 350 dpi

9 Data Acquisition UAV has smaller footprints due to camera type and lower altitude The images have higher resolution (dpi) UAV requires more overlap/sidelap Manned Aircraft UAV

10 Flowchart: Data Acquisition Mission Planning Establish Ground Control Fly Courtesy of Lewis Graham, AirGon

11 Flowchart: Data Acquisition Mission Planning Establish Ground Control Fly Ground Control Points (GCPs) Accuracy of geographical references is hard to achieve without GCPs GCPs locations should be Accurately surveyed Identifiable in the imagery Scattered each corner of project's boundary the more the merrier A minimum number of ground control points (around fve) is generally required by the software for the referencing process to function.

12 How to set optimal number/locations of GCPs For this project, 3 surveyed points were used and added 9 more. (11 pts total) GW identifies not only sufficient but optimal number and locations of GCPS for the best results in both urban and wilderness area through knowledge from certified land surveying and experience from numerous past projects.

13 Processing Flowchart Align Photo Add GCPs QC Horizontal & Vertical Accuracy Manned Aircraft UAV Tie-points (Agisoft) Tie-points (Pix4D) GCP QC (Agisoft) GCP QC (Pix4D) 9,673 (Tie-Points) 71,629 (Tie-Points) 45,443 (Mean Keypoints / Images) 55,740 (Mean Keypoints / Images) X error(m) Y error (m) Z error (m) X error(m) Y error (m) Z error (m) X error(%) Y error(%) Z error(%) X error(%) Y error(%) Z error(%)

14 Processing Flowchart Digital Surface Model Classification Digital Elevation Model Contour Volumetric Analysis Orthomosaic Draft Orthomosaic GSD 0.1' Planimetric

15 Point Cloud

16 Ground / Non-ground Classification

17 Digital Elevation Model Manned Aircraft UAV

18 Orthophotography Manned Aircraft UAV

19 Processing Flowchart Digital Surface Model Classification Digital Elevation Model Contour Examples Volumetric Analysis Orthomosaic Draft Orthomosaic GSD 0.1' Planimetric

20 Seamline UAV corrected Post-processing required to resolve the problem

21 Seamline Manned Aircraft Manned Aircraft has much less number of seamlines than UAV data

22 Buildings UAV pre-processed Buildings often have distortion due to small the tile size

23 Buildings UAV corrected Post-processing required to resolve the problem

24 Buildings Manned Aircraft Manned Aircraft has larger tile

25 Color Balance UAV pre-processed Distorted Color balance from tile to tile

26 Color Balance Manned Aircraft Manned Aircraft has larger tile

27 Ghost Effect UAV pre-processed Higer rate of overlap and sidelaps Overlapped images from different angle

28 Blending Effect UAV pre-processed A software glitches

29 Blending Effect UAV corrected

30 Height Distortion UAV pre-processed UAV corrected Manned Aircraft Flying at 200~300 ft vs manned aircraft 3000 ft Objects leaned from height exact location as bottom

31 Height Distortion and Shadow Manned Aircraft Lower flying altitude with a wide angle lens: oblique angle into topdown UAV Jul :00 shadow ratio: 124/100 Oct :45 shadow ratio: 134/100

32 Drone Traces UAV Traces of shadow of drone due to flying at a low height and taking photos constantly

33 Conclusions High Resolution Products Cost effective in smaller project area Not competing, but complementary technology Recognize New Quality Standards Low Cost Platform Generous conditions for data acquisition Frequent data acquisition available for monitoring sites However, UAV-data requires more sophisticated processes the quality of UAV-products depends on photogrammetric knowledge and skills

34 THANK YOU geowingmapping.com