AERIAL SURVEYS

Hawke's Bay Herald-Tribune, Volume 81, Issue 62, 6 December 1937, Page 8

AERIAL SURVEYS

Use in Miiitary and Civil Work ADDRESS TO ROTARIANS The use of aerial surveys in civil and miiitary work was the subject 'of an address given to members of the Hastings Eotary Club at the weekly luncheon of the club on Friday, by Mr P. van Asch. The address was illus- i trated by means of photographg taken from the air, and at the conclusion the | speaker was heartily thanked for a most interesting taik. The possibilities of aerial mapping nnd photography, particularly in connection with artillery work, were recognised early in the war, and this was osed to a large extent by bcth sides, said Mr Van Asch. In that period, however, the equipment used was very poor, and the results for the main part unsatisfactory. To-day, on the other hand, a great advance in the construction of equipment had been made. In this work Germany was more advanced than Britain , although the latter could produce some good equipment, The camera, which cost £500, weighod 159 pounds. The actual work of photography deuianded the most careful Attention from the pilot of the aeroplane used, for a regular hfeight and steady progress of the machine were necessary for a perfect film. If the machine were as little as two degrees o.ff the centre of the eorreet course, the film wonld be useless for praetical purposes. Mapping for mining work in tbe South Island required a height of 12,000 feet — one at which results were obtainable only in the clearest of weather. In this connection New Zealand was more fortunate than England, for while the latter had only 150 hours a year available on the average for such work, the New Zealand fiigure was three times that. Six-inch mapping, which waa used more commonly, required a height of 9,000 feet. A series of pholographs produeed by the speaker showed the results of aerial survey work m various classes. Aerial maps in the series showed surveys of rivers, towns, lakes, and forests. In conclusion, the speaker stated that while aerial survey would not eliminate ordinary survey work, it was used to provide additional detail.