Direct exterior orientation determination in close-range photogrammetry for cultural heritage recording
Rene co-supervised former Ph.D. student Dr. Melanie Kirchhoefer. In this project a low-cost photogrammetric recording system was developed that is capable of direct exterior orientation determination. The system comprises a consumer-grade digital camera, a small-size orientation sensor and a GPS receiver. The achievable absolute and relative accuracy was assessed during performance tests at a test field and two cultural heritage sites. It was demonstrated that the system is usable for medium accuracy (20 cm) cultural heritage recording, potentially reducing cost by allowing non-specialists to become involved.

PhD Thesis

---

NERC Project: Capturing all fresh information on the Zhouqu landslide disaster, in the Gansu province of China that took place on the 8th August 2010 - Rene was working in collaboration with the PI Dr Tom Dijkstra, Co-I Professor Jim Chandler and Dr Enoc Sanz Ablanedo at Loughborough in conjunction with the British Geological Survey and the University of Portsmouth to adopt a scientific approach to collect data, verify their robustness, make impartial observations and develop reliable process models which will be essential to develop appropriate mitigation strategies for the future. Images of the area were used to extract digital elevation models and orthophotos which were initially used for a mapping programme.

Zhouqu DEM+Orthophoto (25 MB)

---

Comparing low cost photogrammetry and laser scanning for accurate spatial measurement and representation of building fabric - Rene is PI on a RICS funded project (November 2009 - November 2010) to compare the accuracy achievable using laser scanning and photogrammetry for close range surveying and monitoring of structures and building fabrics. The study will answer the question: "What is the most suitable technique for specific measurement tasks in the construction environment in terms of data acquisition, data processing and costs effectiveness?" This funded project is being conducted through collaboration with Jim Chandler at Loughborough.

---

Car crash investigation - a collaboration (Rene and Jim Chandler) with the Crash Investigation Manager, Rob Newton, at the Transport Safety Research Centre, Loughborough University has been established to investigate the effect of side and frontal impacts on cars. A terrestrial laser scanner is being used to quantify deformations that have occurred by comparing crashed areas with unaffected zones.

Difference image (17 MB)

Crash volume

---

Spatial measurement with consumer grade digital cameras - Rene has developed the potential of consumer grade digital cameras for accurate spatial measurement in his PhD Thesis. An approach is introduced to assess camera stability based on comparing the accuracy in the reconstructed object space. This study also identified residual systematic error surfaces and a methodology that uses a mildly convergent image configuration was developed, which removes these systematic errors. This methodology can reduce the need for an accurate lens model and effectively increase the accuracy achievable with non-metric digital sensors.

Journal Papers - Academic Journals

KIRCHHÖFER, M.K., CHANDLER, J.H., WACKROW, R. AND BRYAN, P. (2012). Direct exterior orientation determination for a low-cost heritage recording system. Photogrammetric Record, 27(140), 443-461.

Sanz-Ablanedo E., CHANDLER, J.H. AND WACKROW, R. (2012). Parameterising internal camera geometry with focusing distance. Photogrammetric Record, , 27(138), 210-226.

WALSTRA, J., CHANDLER, J.H., DIXON, N. AND WACKROW, R. (2011). Evaluation of the controls affecting the quality of spatial data derived from historical aerial photographs. Earth Surface Processes and Landforms, 36(7), 853-863.

WACKROW, R. AND CHANDLER, J.H. (2011). Minimising systematic error surfaces in digital elevation models using oblique convergent imagery. Photogrammetric Record, 26(133), 16-31.

WACKROW, R. (2011). Digital Camera Calibration. EuroSDR Official Publication No. 55. Photogrammetric Record, 26(135).

WACKROW, R. AND CHANDLER, J.H. (2008). A convergent image configuration for DEM extraction that minimises the systematic effects caused by an inaccurate lens model. Photogrammetric Record, 23(121), 6-18.

WACKROW, R. and BARTELS, M. (2007). RSPSoc Annual Conference 2007: Challenges for earth observation - scientific, technical and commercial. The Photogrammetric Record, 22 (120), 356 - 359.

WACKROW, R., CHANDLER, J.H. AND BRYAN, P. (2007). Geometric consistency and stability of consumer-grade digital cameras for accurate spatial measurement. Photogrammetric Record, 22(118), 121-134.

Selected Conference Contributions - Refereed

KIRCHHÖFER, M.K., CHANDLER, J.H. AND WACKROW, R. (2011). Cultural heritage recording utilising low-cost close-range photogrammetry. Proceedings of CIPA 23rd International Symposium, 12 – 16 September 2011, Prague, Czech Republic, 8 pages [on CD-ROM].

WACKROW, R., CHANDLER, J.H., DIJKSTRA, T., SANZ-ABLANEDO, E. AND XINGMIN, M. (2011). Incidental terrestrial imagery for post disaster spatial data capture of debris flows. Geomorphometry 2011 Conference Proceedings in: Geomorphometry 2011, Edited by T. Hengl, I.S. Evans, J.P. Wilson and M. Gould, 7-11 September 2011, ESRI Campus, Redlands, USA: pp.11-14.

Lim, S., Buswell, R.A., Le, T.T., WACKROW, R., Austin, S.A., Gibb, A.G.F. AND Thorpe, A. (2011). Development of a viable Concrete Printing process. Proceedings of the 28th International Symposium on Automation and Robotics in Construction (ISARC2011); Seoul, South Korea, 29th June - 2nd July 2011, 665-670.

KIRCHHÖFER, M.K., CHANDLER, J.H. AND WACKROW, R. (2010). Testing and application of a low-cost photogrammetric recording system suitable for cultural heritage recording. Proceedings of RSPSoc and Irish Earth Observation Symposium; University College Cork, 1st-3rd September 2010, 330-337 [Also on CD-ROM].

WACKROW, R., CHANDLER, J.H. AND GARDNER, T. (2008). Minimising systematic errors in DEMs caused by an inaccurate lens model. The Inernational Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, xxxvii(B5), CHEN Jun, JIANG Jie, Hans-Gerd MAAS, International Society for Photogrammetry and Remote Sensing, xxi Congress, Beijing, 3rd July 2008, 1-6, [Also on CD-ROM].

CHANDLER, J.H., WACKROW, R., SUN, X., SHIONO, K. AND RAMESHWAREN, P. (2008). Measuring a dynamic and flooding river surface by close range digital photogrammetry. The Inernational Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, xxxvii(B8), CHEN Jun, JIANG Jie, Hans-Gerd MAAS, International Society for Photogrammetry and Remote Sensing, xxi Congress, Beijing, 3rd July 2008, 211-216, [Also on CD-ROM].

WACKROW, R. and CHANDLER, J.H. (2007). A Convergent image configuration for DEM extraction that minimises the systematic effects caused by an innaccurate lens model. Remote Sensing and Photogrammety Society, Annual Conference (RSPSoc 2007), Newcastle upon Tyne, 11th September 2007, 3.

Other Reports and Contributions

WACKROW, R. and BRYAN, P. (2009). Investigation of the performance of various camera calibration software packages. Report Department Research Series, English Heritage.