Work in progress
• Adapting SPSF (Small patch sphere fit) to fit to higher order shapes (as bellows window)
• Investigating harmonics
– Via surface model
– Via test of thick window
• Writing two papers as potential NIM publications & Mucool notes)
– “Development of photogrammetric methods for quality control of non standard windows”
– “Development of photogrammetric methods of stress analysis”
Photogrammetry Photogrammetry measurementsmeasurements
John with the digital cameraJohn with the digital camera
Twelve photos are taken Twelve photos are taken
at various pressure stagesat various pressure stages
Preparation of the test at NIUPreparation of the test at NIU
View of the window, View of the window, scale bars and targeting scale bars and targeting sys. sys.
View of the window, video View of the window, video camera, digital camera and camera, digital camera and tripod and projectortripod and projector
New presentation tool from GSI
• 3D Viewer– Rays– Camera stations– Scale bar – Autobar (Crucifix or Southern Cross?)– Shapes– Object targets
Scan image
Detect Autobar and coded targets
Resect for initial cameral parameters
Make a list of coded targets in resected images
If a coded target is in >=2 images
Triangulate coded target coordinates
Triangulate object coordinates
Run first bundle (refine camera parameters and coded target positons)
Resect camera parameters
Does image contain >= 4 coded targets?
Automatch
Run final bundle
Photogrammetric Record, 16(93): 503–517 (April 1999)
AN APPLICATION OF CLOSE RANGE
PHOTOGRAMMETRY IN DOLPHIN STUDIES
By S. BRA¨ GER and A. K. CHONG
University of Otago
Abstract
Dolphins are agile animals and are very difficult to measure at sea.
However, for the conservation of threatened or endangered species,
measurement may be vital because it allows a demographic analysis of the
population. Hector’s dolphin (Cephalorhynchus hectori) is a rare species
living only in coastal waters around New Zealand where it is studied from
small boats. This paper describes a stereophotogrammetric technique
developed to measure body length accurately at sea without having to
capture the individual. Constant calibration with the use of a control frame
allowed accurate body length measurements of dolphins to be made with
this low cost system, with a measurement error of 4 per cent to 6 per cent
of actual length.