SPOT
Image Company SPOT
Image Company
The Spot Image company was incorporated in 1982 to market, produce and distribute, worldwide, data returned by the Spot series of Earth observation satellites, a program which has been operational since February 1986 and is guaranteed to remain so for at least the next 15 years.
With a total staff of around 130, the company has a complete and integrated reception and production line. SPOT IMAGE's main activities include :
The companies three main subsidiaries are Spot Image Corporation (Reston, Virginia), in the US, with a staff of 50, Spot Image Services in Australia and SPOT Asia in Singapore.
Data acquisition upon customer demand is fully managed by SPOT IMAGE with an average of 1,000 requests routinely activated at the SPOT mission centre at any one time. This is a key activity as a fast and reliable programming service is a pre requisit to obtain good and timely data set for any type of application. To this end, a consistent analysis of the daily results and priority in programme variance is achieved so that a maximum effort is maintained in the repeatability performance of the satellites.
SPOT data reception in achieved through
To day, about 3 million SPOT scenes have been acquired and archived, ready for selection by potential customers. A digital information catalog and quick look system (DALI) give users a fast access to all technical parameters for each scene received and to visualization of any selected scene on colour quick look samples.
From data reception, SPOT IMAGE has developed a superior capability in satellite imagery processing with a complete production line operating with high through put, short turnaround times and consistent high quality.
SPOT scenes are preprocessed, according to users needs to 3 different levels :
Products are supplied on a great variety of media and formats :
In addition SPOT IMAGE has developed a line of cartographic and value added products. It includes special processing (P + XS merged, true color images, enhanced d'images etc.) and the GEOSPOT« imagemap series (see below) which provide in map sheet format, accurate and up to date geographic information.
GEOSPOT« products are georeferenced and ready to use in geographical information systems.
To day, remote reusing from space has developed from a scientific discipline to an indispensable tool within a large number of applications. At SPOT IMAGE, satellite data is processed and refined into a variety of products for final delivery to customers. All stages, standard processing, geocoding, extraction of elevation models from stereopairs, analysis, production of cartographic or thematic maps and quality control are streamlined in an integrated computerized production process.
In its initial design as well as in its long term planning, the SPOT programme concept is based upon the continuity of service to users worldwide.
SPOT 1 has been in service since February 1986, followed by SPOT 2 in January 1990.
SPOT 3 is tested and stored until the launch planned in September 1993.
SPOT 4 with improved capabilities (middle infra red band) is under construction and SPOT 5 will be a completely new designed satellite with improved ground resolution and continuous stereoscopy.
The SPOT satellites' two viewing instruments (HRVS) when operated simultaneously in the vertical viewing configuration are capable of imaging a 117 km wide strip on the Earth's surface. Both HRVS are fitted with programmable Strip Selection Mirrors giving access, off track, to areas within a 950 km wide corridor. This specific oblique viewing capability greatly increases the frequency at which the satellite can revisit a particular site (4 to 11 times within the 26 day cycle, according to latitude).
Consequently stereopairs, used for relief perception and elevation plotting (Digital Elevation Modelling) are formed from two SPOT images acquired at different viewing angles on successive satellite passes.
A single SPOT scene covers a geographical area of 60 x 60 km.Two alternative modes of imaging are possible :
SPOT key features such as ground resolution, repeat registration, acquisition programming and stereo capabilities makes the system the current most advanced programme to acquire up to date geographic information.
Many operationnal applications in a variety of domains ranging from Earth sciences to economic planning and decision making takes benefits of SPOT data : vegetation, agriculture, forestry, soils, geology, erosion, oil and mineral exploration, water resources, urban and rural planning, civil engineering, development projects, or environmental monitoring.
Since 1988, the company has developed an important activity in project implementation and management including analysis of customer requirements, feasibility studies, preparation of technical proposals in any field of applications, in partnership with a variety of service companies.
The company's senior management has constantly expressed its commitment to the promotion and expansion of this type of services for the benefit of all.
The Project Department at SPOT IMAGE, with a team of 20, is dedicated to assist customers in projects involving the use of satellite based remote sensing data and to offer comprehensive solution package to a particular problem. Project management gives the end user a total solution from a single source. The SPOT IMAGE Project Management team combines a large expertise in all aspects of remote sensing and geographic information with a unique knowledge of the SPOT system and masters the full range of the system capabilities in terms of satellite programming, data acquisition and processing for all kinds of applications.
Thanks to a wide network of value-added and service companies, project implementation is jointly carried out with experienced partners selected according to a given application: cartography, land use, land potential, agriculture, forestry, erosion, civil engineering, environment etc.
The process of transferring know-how and technology is of decisive importance for projects, especially in developing countries. This is accomplished through cooperation in the definition objectives, specification of requirements and solutions down to equipment level and methodology.
Consequently projects usually consist of a package including mapping, data analysis and end results but also staff in house training, technology transfer and hardware/software equipment supply (PCs, workstation for image processing and Geographic Information Systems).
Among a variety of diversified projects conducted with SPOT IMAGE as prime contractor we can briefly mentioned :
To conclude this overview of SPOT IMAGE's activities and abilities in the fields of geographic information, cartography and natural resources development, we would like to stress our unique position on the market as we master an integrated line from data acquisition to application products and thematic studies. Our competence allied to the skill of carefully selected partners gives our clients the assurance of a reliable, efficient and cost effective range of services.
United Nations statistics regarding the state of topographic cartography in the world show that only 44% of the land masses are covered by maps belonging to the 1:50,000 and 1:100,000 scale groups, which are the most important for economic development. In addition, a large part of these maps is obsolete and does not meet the countries'needs for development purposes. Since Landsat 4-TM in 1982 and moreover SPOT 1 in 1986, one can state that mapping with data from space will represent the base of cartography at small and medium scales in the near future.
The uses of space imagery in cartography include revision of existing maps, compilation of new maps and remaking of maps at larger scales than those currently in use. Satellite imagery is suited for compiling general topographic maps as well as thematic maps : vegetation, agriculture, urban and rural land use, geology, pedology, water resources, environment etc.
From concept and design to actual tested performances, SPOT is perfectly adapted to cartographic applications.
The key advantages of SPOT imagery for topographic mapping are the following :
As cartography aims at satisfying user's needs, specifications are moving to benefit fully from the characteristics of SPOT imagery, thus giving rise to new cartographic products filled to answer specific problems in terms of accuracy and information content. Two products are developing particularly rapidly : imagemaps and digital elevation models (DEMs).
Imagemaps are currently the emerging product to answer to the needs for obtaining in a short period of time and at low cost compared with conventional methods, up dated cartographic documents. It is an alternative when the basic mapping is out of date, not accurate enough or does not exist at all.
In several countries the lack of reliable mapping is a serious constraint to development in many sectors, particularly within the fields of rural and urban development and for the planning, management, extraction and balanced use of natural resources and the environment. The use of satellite imagery as the base for map production offers significant advantages which did not exist before the launching of the first SPOT satellite. It is now possible to obtain large volumes of detailed and up-to-date, spatial and geographic information rapidly and at a fraction of the cost for traditional methods.
The satellite imagemaps constitute a completely new type of low-budget map. They are based on the use of precision corrected, edge enhanced single images.
SPOT satellite imagemaps offer many advantages when compared with traditional line maps. In addition to the sharp depiction of typical man-made objects like buildings, roads and urban infrastructure, these maps are easy to relate to reality; they give a clear picture of vegetation cover, land use patterns, cultivated land, shifting cultivation, deforestation, soil erosion, land forms, etc. they show many detailed features which normally are not plotted on line maps or are depicted with general symbols, such as individual cultivated fields, small forest clearings, the different treestands and tree crown patterns, and, in some cases, even isolated trees; in addition, even minor paths and cattle trails often can be identified.
Imagemaps are a source to extract up to date geographic information and at the same time a georeferenced base to transfer users' geographical information. It is both :
They are particularly useful for alternative cartographic document, natural resource inventories, development and planning projects, local and regional resource management and monitoring, urban and civil engineering project, new mapping and map up dating, geographic data base and historical archive.
SPOT imagemaps are map quadrangles in a map sheet format composed of a SPOT image background projected and segmented according to a cartographic system (UTM, Lambert ...) and thus registrable to local maps.
Standard products such as the "GEOSPOT« line are plotted from precision processed SPOT data PAN, XS or PAN + XS merged modes corrected to level 2A, 2B or 3 (orthoimages).
At level 2A, ground control points are not used. Images are corrected according to a map projection system and parallax effects are not taken into account.
At level 2B, ground control points are acquired either from existing documents or by Global Positioning Surveys (GPS). Corrections are made at level of reference and parallax effects are not removed.
Level 3 is achieved using a DEM, for instance derived from SPOT stereopairs and ground control points to produce an orthoimage map.
GEOSPOT« products are proposed at scales ranging from 1:200,000, 1:100,000, 1:50,000 to 1:25,000 or intermediate scales. Specific production parameters include: digital mosaicking with optimization of connecting lines and histogram equalization, edge enhancement and local stretching for image sharpness improvement, standard geographic framing, geographic and cartographic grid and tick marks, standard lay out with map and image indexes.
GEOSPOT« products can be complemented with Names, planimetric features, administration boundaries and contour levels (ortho products) or thematic information, at a price which make this multipurpose product highly attractive.
Many projects have been completed to provide country wide mapping with imagemaps: the Philippines, for natural resources inventory, Morocco for map up dating, Tunisia for forest inventory, Bangladesh for preparing the Action Plan for Flood Control, Egypt for an Agricultural Land Information System among many other ones.
GEOSPOT« in digital format and products derived from are ready to use in any geographic information system.
Digital Elevation Models (DEMs) are now obtained with SPOT by digital automatic correlation. Several softwares are already available and many more are in the experimental or implementation phase. The technique involves the matching of a pair of images in order to determine parallax difference from which a DEM is constructed. Orbital information, ground control points and geometric model are needed. Image correlation is based on feature points or edges structured along epipolar lines.SPOT IMAGE has established a strong partnership with the main companies producing DEMs with automatic correlation techniques, some having already five years of operational experience in this field.
Beside topographic line maps and orthophotos, DEMs are also used to generate in computers a variety of derived products such as slope maps, exposure maps, sun illumination maps, intervisibility maps or perspective views which are used in a wide range of applications: geomorphology, erosion studies, land potential assessment, hydrology, civil engineering, environmental impact studies, site location, flight simulation and serve as a direct input into GIS.
The satellite imagemaps constitute a completely new type of low-budget map. They are based on the use of precision corrected, edge enhanced single images.
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This page was updated October 2, 1995 by J.C.Meunier.
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