Development of the satellite Remote Sensing
activities in Sri Lanka
M.P. Salgado
Deputy Surveyor General,
Sri Lanka
Bandulatha Adikari - C.R.S.
Abstract
Use of Aerial photographs for interpretation and mapping was practiced in Sri Lanka, from about 1960. The compilation of the Base maps on 1/50000 scale, using photogram metric techniques, commenced around 1977. During this time, the Scientists and the Planners in Sri Lanka considered the introduction of satellite remote sensing to its mapping activities, to supplement the acquisition of the urgently needed Land resources data required for the development programmes. Outcome of these efforts was the establishment of the Swiss-Sri Lanka collaborative remote sensing project for the period 1980-1988, with the emphasis for the production of the 1/100000 scale, District land use maps of Sri Lanka. The experiences gained through this project activities are mainly in the application of analogue techniques for the interpretation and mapping. We are also concerned with the constraints experienced, imposed due to the delays in the procurement of satellite imagery, cloud cover, limitations in the analogue techniques for the interpretation of satellite imagery in the context of the Sri Lankan condition etc. Our aspirations for the gradual transition to digital remote sensing in the face of the escalation of the costs due to the commercialization of the production of satellite imagery, the development of the indigenous expertise to meet this challenge, are presumably common concerns, of the developing nations of the Asian Region, and calls for closer regional collaborations, while seeking improved technical cooperation form the developed and industrial countries of the world.
Introduction
Aerial Remote Sensing was introduced to Sri Lanka in 1956, and during the period 1956-1960, the entire Island was photographed on the scale of 1/40,000. This aerial photographic coverage was the basis for the systematic updating of the existing national map series on 1 mile to 1 inch scale, photogrammetry for topographic mapping, and photo interpretation for land use maps. Over the years the updating process of the National map series has fallen into arrears, resulting in a general deficit of upto date basic special planning information. However general surveys and the photogrammetic capabilities of the survey dept. have been steadily improved over the years.
In 1980 a new aircraft was made available to the dept. instead of updating the existing national map series, a new topographic map series was considered on 1/50000 scale, to be completed over 5 years period. This was also the period where large development projects were planned. Alternate strategies had to be considered for the urgently needed land use data required for this purpose.
With the introduction of the earth resources satellite in the seventies, the Swiss Government was requested to assist in the introduction of satellite remote sensing techniques to assist in the introduction of satellite remote sensing techniques, that would help the country in its search for urgently needed basic land use data and mapping. This resulted in the establishment of the centre for remote sensing within the survey department in collaboration with the Swiss govt. the major component of work under this project was in the production of 1/100000, district land use maps by the use of analogue techniques in the interpretation of bulk MSS & RBV imagery and aerial photographs, supported by extensive ground truthing utilizing a multi-stage approach. Thorough the Swiss-Sri Lanka remote sensing project, certain progress has also been achieved in the domain of digital image processing.
