spatial/morphological measurement using close range photogrammetry- guidance from isprs v6
DESCRIPTION
Spatial/Morphological measurement using close range photogrammetry- guidance from ISPRS V6. (with notable input from members of ISPRS Working Group V6). Jim Chandler 1 , Rene Wackrow 1 and Dirk Rieke-Zapp 2 1 Loughborough University, UK 2 University of Berne, Switzerland - PowerPoint PPT PresentationTRANSCRIPT
Spatial/Morphological measurement using close range photogrammetry-
guidance from ISPRS V6
Jim Chandler1, Rene Wackrow1 and Dirk Rieke-Zapp2
1Loughborough University, UK2University of Berne, Switzerland
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
(with notable input from members of ISPRS Working Group V6)
Overview
What can close range photogrammetry provide?
Why produce “tips”? Key points? An illustration!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
What can close range photogrammetry provide?
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Italian Alps- 1990
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Antwerpen- 1991
Black Ven Landslide- 1995 (1)
ARSF imagery March 2nd, 1995
Scale: 1:4,500
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
1995 (2)
Processed using digital photogrammetry Unix workstation (£15K, 1995)
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Automated measurement!– 1m resolution DEM-
1.6 million points in 10 hours
Aboriginal rock art recording, 2004
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Rock Art- Outputs
Digital Elevation Models (DEMs)
Accuracies- 2-3mmOrthophotos
Visualisation “fly-thru”
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Northumberland and Durham Regional Rock Art project
9 of 42
• Partnership between English Heritage and the County Councils for Northumberland and Durham
• Loughborough University advising on the photogrammetry
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Lessons learnt
Don’t underestimate volunteers Added political
benefits!
Technology and the volunteer Hi tech or low?
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Why are “tips” necessary?
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Stated activity! Past experiences-
particularly postgraduates/ volunteers
Two sets!
Who contributed?
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Primarily WG Officers
Also notable input from industry!including:
Marko Tuomien, Datapix Pty Ltd, Queensland, AustraliaStephen Bird, Fluvial Systems Research Inc, Whiterock, Canada
Start simple- start small!
150 small format images of a river channel in Spain- I fly next week and my supervisor doesn’t know about photogrammetry!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Common sense!
Familiarisation- techniques and how software works!
Start with: Small test area captured with perhaps two pairs Ideally use a pre-calibrated camera Establish abundant photo control- easy restitution plus checks
Which camera?
All cameras have spatial measurement potential!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Digital SLR!
Fixed or variable zoom lens?
Never purchase “top of the range”
Camera calibration
Necessary for accurate spatial data acquisition!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
What software? Matlab, PhotoModeler, IWitness, etc.
• camera focal length (f)• principal point offset (xP, yP)• radial lens distortion (K1, K2, K3)• tangential distortion (P1, P2)
-300
-250
-200
-150
-100
-50
00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
(mic
rons
)
Radial Dist (mm)
Radial lens distortion
Fieldwork/control
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Photo acquisition:• Infinity focus/f8• Fastest shutter speed possible/tripod• Obtain redundant imagery
Control Don’t skimp! Well distributed Withhold 20% and use as “checkpoints”
Visit site prior capture images “in pairs/triplets”
Zhouqu- China 8th Aug. 2010
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
“Tips” document, freely available- more later!
Zhou Qu debris flow: Zhouqu mudslides death toll rose to 337 people, 1148 people missing
Measurement potential of imagery!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Measurement potential of imagery!
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011
Video fly-thru!
Gradient of debris slope! Next phase
Conclusion
Prime purpose, raise awareness of photogrammetry and ISPRS Working Group V6: http://isprsv6.lboro.ac.uk/
Special Issue of the Photogrammetric Record: http://onlinelibrary.wiley.com/doi/10.1111/j.1477-9730.2010.00590.x/full
“Tips” document, providing simple guidance. Also some recent work/interests:
Potential of terrestrial imagery Potential of consumer grade digital cameras
Remote sensing- meeting industry needs with NERC expertise, 6th April 2011