The role of Thailand Remote Sensing center in user service to the Southeast Asia region

The role of Thailand Remote Sensing center in user service to the Southeast Asia region

Mrs. Praneet Ditsariyakul, Miss. Niramon Limlamai
Remote Sensing Division, National Research Council
Bangkok 10900 , Thailand

Starting from late 1987, the development of remote sensing applications using satellite data has become more successful in this region due to the fact that Thailand Ground Station has the capabilities to provide the high resolution satellite data of Landsat TM, SPOT and MOS-1 added to the existing MSS. At present, Thailand Remote Sensing Center (TRSC) has a large archive of satellite data which could serve the users' needs of the region. TRSC has progressed through the years to be a center of excellence in this region. TRSC now tries to take a greater role in providing the enhanced quality and quantity of data to users. However, the price of data is still one of the major problems even though TRSC product price is not too high compared to the world standard. It is anticipated that if data cost is reasonable, the use of satellite data will be more side spread and will generate interest among the users in the Southeast Asian region.

Introduction
Thailand Remote Sensing Center (TRSC) under the National Research Council of Thailand , has operated as a land remote sensing data collection center since late 1981. The coverage area of the Thai station (see Figure 1) extends to many countries in Southeast Asia including the Southern part of the People's Republic of China, Taiwan, Philippines, Vietnam, Laos, Cambodia, Indonesia, Malaysia, Bangladesh, Nepal, Sri Lanka and Burma. In 1986, Thailand Ground Station with CIDA grant , was upgraded to receive and process the high resolution satellite data from Thematic Mapper of Landsat-5 and HRV of SPOT-1 and started to receive those data from December 1987. TRSC also coop0erated with Japan's NASDA to construct a new ground station for MOS-1 which stated to receive MOS-1 data from May 1988. In addition to the ground reception facilities, TRSC is equipped with photographic laboratory for data reproduction and analysis systems for data application. The capability of receiving, processing and providing, the multiple satellite data has placed TRSC in a prominent position with the great role in user service to the Southeast Asia region.

Satellite data and service avalibale
At present, Thailand Remote Sensing Center has extensive archives of Landsat MSS and TM of more than 130,000 scenes and more than 7, 000 scenes foe SPOT data.

The User Service Unit of TRSC, which is responsible for providing users with satellite data acquired by the Thai station, offers various forms and scales of photographic and digital products including some special services.

Some examples of services provided are :

Scene search information : Users who are interested in data for a particular area can contact User Service Unit for assistance. The listing of available scenes can be compiled and provided free of charge. To request for a search, the users should provide path / Row number for Laandsat data and K/J number for those of SPOT. They can also specify the maximum acceptable cloud cover, minimum image quality and the time of year preferred.
Microfiche subscription : The acquired TM and SPOT images are reproduced on microfiche. The TM microcatalog is called cyclic microfiche. An individual microfiche contains acquired scenes for one geographic area during one cycle ( every 16 days) . The users are also able to use microfiche fro preliminary evalution of image quality and cloud cover. Microfiche subscription is available on an annual basis. When ordering, the users have to indicate the geographic area requi9red. TM cyclic catalog areas are shown in Figure 1.

Services of satellite data are not restricted to only domestic users but to all interested users around the world.

Distribution of Landsat MSS and TM data is based on the agreement made originally with NOAA (which is now transferred to EOSAT). Thailand has also signed the agreement with SPOT IMAGE for the reception and distribution of SPOT data but this was already expired on December 31, 1989. Nevertheless, TRSC can still distribute the existing SPOT data to users under additional agreement with SPOT IMAGE.

With the availability of the multi-level satellite data, the amount of volume and value of data provided is increasing each year. The total value of data provided in FY 1989 (October 1988 - September 1989) was more than 500,000 U.S. Dollars and the trend of FY 1990 is much higher.

However, the international users are still the principal purchasers of digital product both in volume and value from Thailand Ground Station.

The role of TRSC in user service in the region
Due to the fact that Thailand Ground Receiving Station is located at the appropriate geographic site as the center of the Southeast Asia region and has the facilities and capabilities of receiving, processing and providing multiple satellite data; TRSC, therefore, has a great role in supporting utilization and application of satellite remote sensing data of the country in this region. Accordingly the enhanced quality and quantity of data is the main goal of TRSC in area of user service.

Although satellite data have been more widely used, there are certain problems which most of the countries in the region try to overcome, i.e the data price and the date analysis facilities.

Eventhough TRSC product price is not too high compared to the world standard, most of the d4eveloping countries still cannot afford. Funding sources need to be sought for otherwise chances to use the satellite data would be slim. Besides, the analysis systems are scarcely available even in some remote sensing agencies. This courses difficulties for the users to use satellite data to extract information that would be useful not only to the respective agencies but also to the community as a whole. With this respect, TRSC is aiming at serving the region with a broad range of satellite data that are not only affordable but also of high quality, and wherever possible, with some specific enhancements such that the image products can be readily used without much need for sophisticated analysis equipment . Emphasis will be put on cooperation between TRSC and Asian countries to broaden the use of satellite data for the benefit of the region.

Future plan
While satellite data has proven useful and more widely used, cloud cover is a critical problem for the counties in tropical zone such as those in Southeast Asia. The availability of satellite data is so scarce in rainy season which lasts about 5-6 months a year. The capability as radar or microwave sensors are required for the next generation of natural resources survey satellite.

Thailand has planned to receive data from the future all - weather satellites such as the ERS-1, JERS-1, Radar sat etc. so that the countries in the region can be served and also benefit from these data. Collaborative programmes between Thailand and satellite operating countries will be another important element in ensuring the continuity of satellite data for the region.

Conclusion
Thailand is one of the active countries participating in satellite remote sensing programmes. Thai station can serve more than fifteen countries within the region. Satellite data products can be reproduced in most standard formats and distri9buted to national and international users upon request. Thailand has plans to continue its role in user service by providing the enhanced quality of the future microwave satellite data. Cooperation on a bilateral and multi-lateral basis in making the price on cost of data low will be strengthened in order that the users in this region can afford and as a result the satellite will be used more widely and effectively

Fig 1