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THEOS Satellite Data ServiceHead Geo-Informatics and Space Technology Development Agency Thailand Jirawan Charoenrath Acting Chief Marketing and Sales Relation Group Geo-Informatics and Space Technology Development Agency Thailand jirawan@gisdta.or.th Abstract THEOS, Thailand’s state-of-the-art satellite imaging system, is fully operated by the Geo-Informatics and Space Technology Development Agency (GISTDA), Ministry of Science and Technology. The satellite’s sensor and orbit characteristics have been chosen strategically to provide worldwide geo-referenced image products for interdisciplinary applications including agriculture, forestry, land use, environmental monitoring, cartography, water resources, coastal zone and natural disaster management. With its oblique viewing capabilities, THEOS can support timely image of any part of the world in less than 3 days, with the resolution of 2 meter in panchromatic and 15 meter in multispectral images. The THEOS visible blue band is similar to that of the Landsat Thematic Mapper while the visible green and red and the near-infrared bands are similar to those of the SPOT family of imagers. GISTDA can supply THEOS standard products which include Level 1A, Level 2A, and PAN-Sharpening data and THEOS value added products which include Level 2B data, Digital Terrain Model : DTM, and Ortho-Image. The customers can be assured that THEOS data format and quality is intended to be consistent with international standards and in conformance with the “Principles Relating to Remote Sensing of the Earth from Outer Space” adopted by the United Nations. The objective of GISTDA is not only to deliver high-quality image data products and services in a reliable and timely manner to satisfy a wide range of customer needs worldwide, but also to develop a worldwide network of distributors to market and sell THEOS data products under license. THEOS Successful Launch THEOS satellite was launched on 1 October 2008 into a sun-synchronous orbit at an altitude of 822 km at the equator by Dnepr LV rocket from Dombarovsky, Yasny. It will circle the Earth in 101.4 minutes with an equatorial crossing at 10:00 am local time on the descending track (North to South) track completing a little more than 14 orbits per day. THEOS has a design life of five years with a follow-on mission now in the planning stage. The satellite will transmit data to the THEOS Image Ground Segment (IGS) which will house the data reception and processing facilities. Command and control of the satellite will be provided by the THEOS Control Ground Segment (CGS) in Thailand. THEOS Satellite and Sensors The THEOS satellite (figure 1) payload includes a panchromatic telescope for high resolution imaging, a wide swath multispectral camera system, and an electronic unit which processes the image data for storage and later transmission. The satellite bus component provides all the service functions such as the mechanical interface with the launch vehicle, power, attitude and orbit control, thermal control, and propulsion. The THEOS Optical Payload consists of two pushbroom scanners that use linear CCD arrays. The multispectral scanner images a 90 km swath and operates in three visible and one near-infrared band producing imagery with a nominal resolution of 15 meters (GSD) at nadir (i.e. when the viewing direction is vertical). The visible green, visible red, and near-infrared bands have similar characteristics to the corresponding bands of the sensors carried on the SPOT series of satellites. The visible blue band is similar to that of the LANDSAT Thematic Mapper instrument. The panchromatic sensor images a 22 km swath and produces imagery from a single broader band of the spectrum covering the visible and a portion of the near-infrared at a nominal resolution of 2 meters (GSD) for the nadir viewing position. Table 1 provides information on these optical sensors.
 Figure 1: THEOS Ground Control Station, Si Racha, Chonburi THEOS is also designed to provide oblique viewing. It will normally be operated to collect imagery within ± 30º of the satellite ground track allowing imagery to be collected for any area within a 1,000 km access corridor. Oblique viewing increases the frequency with which an area can be viewed. The frequency depends on latitude with more frequent coverage possible at higher latitudes. For Thailand, an area can be imaged 9 times during a 26 day orbital cycle with the interval between acquisitions ranging from 2 to 5 days. The satellite is designed to rapidly change viewing direction increasing the range of locations that can be imaged in a single pass. Where urgent image access is imperative the satellite is capable of oblique viewing to as much as ± 50º. However at extreme viewing angles beyond the nominal ± 30º the quality of the imagery may be reduced. THEOS can acquire stereo imagery for Digital Elevation Modeling and viewing with relief perception. Either of two acquisition methods can be used. Single pass stereo imagery is acquired by pointing the satellite forward and then backward along the satellite ground track during a single pass. Multiple pass stereo can be acquired by collecting imagery of the same ground area from different satellite tracks by using different across-track viewing angles. Designed to provide service worldwide, THEOS imagery can be transmitted in real-time when in range of a receiving station or stored onboard and transmitted later during the same orbital pass. THEOS Control and Scheduling At the present, GISTDA has a ground receiving station (figure 2) at Ladkarbang with a receiving capability of 2,500 km. and a new ground control station at Si Racha, Chonburi. GISTDA has 2,500 km. Coverage Area at Ladkrabang, Thailand (figure 3).  Figure 2: THEOS Ground Control Station, Si Racha, Chonburi The S-band antenna is on the upper-left corner and the X-band antenna is on the upper-right on the main building.  Figure 3: 2,500 km. Coverage Area of the GISTDA Space Technology Center at Ladkrabang, Thailand. THEOS System Operations will be as Follows:
Archived Data : 1 to 3 Days Turnaround (with conditions applied) Orders for archived data received before 15:00 Thailand local time can be processed immediately and sent out to the customers within 1 working day for an order less than 10 products for Level 1A or 2A. Pan-sharpened products can be processed and sent out within 1 week. New Image Acquisitions : approximately 3 Days Turnaround To acquire new imagery, requests must be received at least 24 hours before the satellite pass from which the imagery must be acquired. THEOS Data Products THEOS Standard Products
In order to provide high level THEOS image products, the value added products can be generated depending on the customer requests and additional data for image processing, detailed as the following ; THEOS Value-added Products Consistency with UN Principles and International Standards It is GISTDA’s intention that THEOS data format and quality will be consistent with international standards and in conformance with the “Principles Relating to Remote Sensing of the Earth from Outer Space” adopted by the United Nations. Confidentiality and Security GISTDA reserves the right to withhold data from rogue nations, or to warring states except under the auspices of the United Nations or to Governments recognized by the Government of Thailand. Thailand will not provide data of areas deemed to be sensitive by the Thai Ministry of National Defense. GISTDA requires that the integrity of THEOS data is guaranteed. Distributors will be required to have in place suitable security measures to ensure that THEOS data products are generated according to the required specifications and that there has not been any unauthorized alteration of the original data. In recognition of the proprietary interests of some clients, all order information will be treated as confidential and used by the distributor solely for the purpose of order fulfillment and provided only to GISTDA for purposes of security review. Distributors will be required to implement suitable order processing procedures that will ensure confidentiality. Cost Recovery and Pricing GISTDA has developed a pricing policy that is designed to encourage the development of new applications and new markets, to compensate the Government of Thailand for its investment in the THEOS program, and to recover a portion of THEOS program costs from the sale of THEOS data to commercial users at competitive prices. The Government of Thailand has funded the THEOS program and through GISTDA owns and operates the THEOS satellite system. To ensure that the people of Thailand receive full benefit from their investment, GISTDA will be the sole distributor of THEOS data within Thailand. THEOS imagery for non-commercial applications will be provided to government, and qualified academic and research users at subsidized rates. Commercial users in Thailand as well as internationally will be charged commercial rates. Commercial rates will include volume discounts for bulk purchases. GISTDA will provide a mechanism whereby subsidized imagery can be obtained by qualified educational and research users outside Thailand either through their local distributor or directly from GISTDA depending on the terms of the distributor’s agreement. There will also be provisions for commercial users to request imagery at subsidized rates for the purpose of developing new applications of THEOS data. In return for receiving data at subsidized rates, all researchers obtaining data from the THEOS mission must provide the results of their research to GISTDA at the earliest possible date, whether or not the research is to be published. THEOS data must be obtained directly from an authorized supplier and cannot be reproduced without permission unless it has previously been made available openly (with appropriate approvals) electronically - e.g. through the internet. Commercialization In an effort to promote commercialization of THEOS data products, GISTDA will take steps to assist the private sector in developing new applications by providing such support as subsidizing access to data to qualified applicants, information about successful applications, and promoting online forums and information resources for users to share information and be apprised of relevant THEOS news. Role of Public and Private Sector GISTDA sees the development of a thriving private sector offering commercial services using THEOS data to be an essential component of the long-term success of the THEOS program. For this reason, GISTDA will not compete with commercial firms in adding value to THEOS data. Only where there is not a commercial market, or where the private sector is unwilling or unable to meet needs that could be served by applications making use of THEOS data, will GISTDA consider pursuing applications markets. Data Bulk Purchase Bulk purchase agreements with clients using large volumes of THEOS data will be negotiated on a case by case basis. These agreements will be undertaken in consultation with the relevant distributor for the region. Data Access THEOS data are to be distributed on a non-discriminatory basis except for security restrictions as noted previously. Data Archiving and Access to Archives All data from the THEOS satellite will be archived in Thailand. Distributor agreements will specify the format, mode of transportation and delivery schedule for back up copies of all received THEOS data to be sent to GISTDA. Access to archived data will be controlled so as to respect distributor agreements. Order fulfillment from the archives will be given the same level of confidentiality as regular orders, i.e. information about the client placing an order, the geographic region, or data products requested will not be released to any third party. The information will be used solely to fulfill the order and to ensure the security conditions stated above are satisfied. Order Desk and Acquisition Priority Distributors will be served by an order desk responsible for receiving acquisition requests, scheduling data acquisitions, and confirming data acquisition by the receiving station. The spacecraft scheduling acquisition priority is: 1. Spacecraft health and safety; 2. National security; 3. Emergencies in the following order: 3.1. National request; 3.2. Socio-political request; 3.3. Thailand’s response to international humanitarian efforts such as response to a natural disaster; 3.4. Environmental emergency; and 3.5. Commercial urgent request; 4. Image quality and calibration; 5. Time critical requests; 6. Non time critical requests; 7. Background mission requests; and 8. GISTDA requests not in conflict with other requests. Data Sharing Restrictions on the sharing of data and derived proprietary information are detailed in the licensing agreement which is discussed under Legal Requirements (Section 9). In general, the sharing of data among commercial users is restricted. Where data is used for non-commercial purposes including education and research sharing of data is permitted under the conditions stipulated in the licensing agreement. Data Dissemination for Public Good and International Aids For selected applications that benefit the public good, GISTDA will make certain image data available for non-commercial purposes to organizations and/or the public within Thailand. As well, GISTDA will consider providing subsidized access to THEOS satellite data to help developing nations cope with resource and environmental management, disaster response and planning on a project-by-project request basis. Data Standards GISTDA is actively engaged in the development and adoption of international standards in the geospatial field. THEOS data formats, metadata, and other characteristics will conform to generally accepted standards in the geospatial field. Ownership and Copyright Ownership and copyright of THEOS data is detailed in the THEOS licensing agreements. In general, within the limits imposed by security or commercial considerations, space-borne remotely sensed data from the THEOS mission will be made available without discrimination to the government of any sensed state upon a request from such government, on reasonable terms and conditions, which may involve commercial conditions, as soon as the data becomes available. The licensing agreement contains wording that protects GISTDA and distributors from legal indemnities resulting from such events as losses to the user resulting from use of THEOS data. Operational Versus Developmental Data Use Data for commercial applications that are operational will be priced at commercial rates. GISTDA is committed to encouraging the development of new products and services that make use of THEOS data and show promise in increasing future data sales. For this reason GISTDA will contribute expert advice and subsidized image data for development projects that are likely to result in new products and services that make use of THEOS data. Such projects will be decided on a case by case basis. Bulk Monitoring Versus Specialized One-Time Use GISTDA is committed to encouraging bulk purchases of THEOS data and will offer discounted pricing that will be negotiated for individual cases. At the same time, GISTDA recognizes that there are many important high value applications that make use of only a few images. Great importance is placed on ensuring that the process of placing and receiving an order for image data is convenient and efficient for both large volume users and those ordering a single image. Request for Proposals (RFP) GISTDA is currently inviting prospective distributors or operators of receiving stations who may be interested in entering into a distributor and/or reception agreement. The RFP includes the technical requirements and information on the process for becoming a distributor or reception station. Those who are interested may contact GISTDA directly for further information. Conclusion The satellite as well as the development of the ground segment necessary to operate and control the satellite directly from Thailand has been built under contract by the French EADS Astrium for the Geo-Informatics and Space Technology Development Agency of Thailand (GISTDA) a Public Organization under the Thai Ministry of Science and Technology. The THEOS satellite is based on EADS Astrium's new generation of high performance AstroSat optical Earth observation satellites and benefits from the company's extensive experience in this field which started with the SPOT and METOP satellites. The satellite was designed to last for at least 5 years, but the propellant on board the spacecraft is sufficient for the satellite to remain in the orbit for eight years. |