ENG-1979 — Page 152

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touring for the standard metric 1:1,000 series of plans. Investigations were under way into the acquisition of a sixth plotter which will have the flexibility to map from terrestrial photography, mainly for surveys for the Geotechnical Control Office. Aerial photography for photogrammetric plotting purposes, engineering and environmental studies is supplied by the Air Survey Unit, assisted by the Royal Hong Kong Auxiliary Air Force.

The computation and adjustment of a new precise control system throughout Hong Kong was completed during 1979 with excellent results. This followed the reobservation of the entire primary trigonometrical network, with subsequent breakdown to the second order network. A trilateration system - involving the precise measurement of the lines between intervisible trigonometrical stations - was employed. Survey control of very high accuracy is now available and will meet the requirements of any engineering or other works.

Projects undertaken or completed by the Survey Branch during 1979 included revision for second editions of the 1:20,000 topographic dual language map series; the reprinting of Hong Kong Streets and Places, Volumes 1 and 2; the production of the fourth ‘Country- side' series map showing the Sai Kung peninsula and Clear Water Bay; and design work for the fifth 'Countryside' map covering Sha Tau Kok and Plover Cove.

Other maps and charts which were revised and reprinted included the popular Hong Kong Official Guide Map, the Hong Kong Harbour Plan and the 1:50,000 and 1:100,000 colour maps. Design work for the 1:5,000 New Territories series was completed but production of this and the proposed 1:100,000 monochrome series was deferred. A pro- gramme for the production of 1:1,000 interim sheets to cover active development areas, required by town planning and engineering authorities, and by consultants, resulted in 500 sheets in metric form showing imperial contours with converted metric values.

The Public Works Department's Survey Training School provides training for both the survey and cartographic disciplines. During the year, 173 government officers attended various courses at the school.

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