Commission Boards 
  
Commission 1, Primary Data Acquisition: 
The following is a compilation of major items of interest supplied by mapping institutions 
throughout Australia. 
Camera Calibration: 
"In flight” calibration has been adopted by the Lands Department of South Australia. A specially 
marked test field 5.8 x 5.8km square (to be extended to 9.4 x 9.4km square) is used. The results of in- 
flight testing are preferred to those from laboratory methods. 
The National Measurement Laboratory performs camera calibration for most other institutions in 
Australia using a Hilger and Watts Goniometer. An autocollimator mounted onto this equipment allows 
for the determination of the principal point of autocollimation and the focal length with the one piece of 
equipment. The Principal Point of Symmetry is also determined in the calibration process. 
Flight and System Navigation: 
The Department of Lands in South Australia is installing a Litton 72 INS Inertial System which will 
provide ample navigation accuracy for photo scales as large as 1:40,000. Inertial navigation systems are 
also being considered by the Mapping Section of the Broken Hill Proprietry Company (B.H.P.). 
An inertial platform and attitude indicator is being developed in Australia for the Division of National 
Mapping. 
For navigation in difficult and remote areas BHP has effectively used a theodolite station or stations 
on the ground, and a ground to air communications link. 
Colour and Multispectral Photography: 
BHP has found colour photography advantageous for mapping and photo-interpretation work. For 
illumination in stereoplotters, they have installed very high voltage "cold" gas discharge tubes with 
specially selected phosphors, balanced for the whole of the spectrum. 
Automatic Processing: 
Automatic processors are used extensively in Australia. Only one specific report has been received 
on their application, from the South Australian Lands Department, who have used the Versamat ll on 
many different types of photography, with only one minor problem. 
Image Quality: 
The application of Modulation Transfer Functions to the specifying of image quality and thereby the 
prediction of optimum ground target sizes has been extensively investigated at the University of New 
South Wales. An empirical formula has been derived for predicting the optimum size of circular and 
cross-type targets using an artificial background for a number of different scales and instrument optical 
magnifications. This formula will be tested against results in practice. 
Dr. J.C. Trinder 
Commission Il, Instrumentation for Data Reduction: 
Of the four major topics set down by the General Assembly for Commission Il for 1972-76, Australia 
has been able to contribute on only one:— Automation of Instruments. 
Six government and two commercial mapping agencies and three tertiary education 
establishments are using 'on-line' techniques for the capture of two/or three dimensional coordinate 
data from stereoplotting instruments or comparators. 
Data is recorded through hard-wired conventional equipment or special interfaces on 
minicomputers onto paper tape, magnetic tape or disks. 
Validation of the recorded data is carried out in many ways depending on the needs of the user. 
Mostly this is achieved using computer operated flat-bed or drum type incremental plotters.