Satellites for French Guiana

Earth observation technologies are today fully capable of providing information and keeping a watch on different environments and society. These technologies can be used for resource management and environmental monitoring. In French Guiana the possibilities for development in this field are considerable. With the installation of the SEAS project, which will monitor the Amazonian environment by satellite, French Guiana has become a world leader in the field of remote sensing applications.

Space technologies used for observing Earth

Space technology and more generally cartography are increasingly important for environmental and societal research. In French Guiana those responsible for managing the environment and other decision makers need to analyse very wide-scale phenomena: urban growth, demography, the dynamics of different environments and cultural practices. Space technologies can provide answers to all these questions.

The chief difficulty for those who need to study these phenomena is their partial knowledge of the environments concerned. Only recent data are available for French Guiana and no historical data sets, expertise or systematic planning has been developed. To acquire the necessary information to keep track of resources, monitor dynamic phenomena and manage the environment different methods are required (image processing, cartography etc.). But these alone are usually not enough.

Remote sensing, however, can harness the power of Space technology to provide new sources of information. Earth observation data can serve as all of the following :

• tools for analysis and synthesis
• legal proof
• evidence or indication of change
• tools for communication and data transfer

They have also shown their usefulness in enhancing and applying our knowledge of tropical environments. Now, however, these technologies must be applied more widely to serve society, especially with the issues it will have to confront in the future.

Remote sensing for French Guiana

Remote sensing has been used before in French Guiana. Since 1988, IRD (or ORSTOM as it then was) has been publishing maps from satellite data which could be used to:

• describe coastal dynamics
• map degraded forests
• monitor urban dynamics
• monitor wetlands

However, since there was no receiving station capable of providing data in a usable form, studies could only be done some time after the images became available or were scheduled. For instance, it took two years of programming requests on SPOT to obtain a few images from which to map certain parts of the Petit Saut dam.

The experience did at least show that it was possible to map the extending water and even to calculate changes in the volume of water between images taken at two different times. However, without data, these methods cannot be put to practical use, however effective the results might be for managing ecosystems.

In the same way, land-use maps created by remote sensing can show how individual communes are developing. Nevertheless a project on this theme had to be suspended for lack of usable data.

The SEAS receiving station

The SEAS project, which will monitor the Amazonian environment by satellite, has been set up precisely to overcome these problems. It will include an antenna in French Guiana for receiving SPOT and ENVISAT data. Local decision-makers, research organisations and Guianese universities will have permanent access to data from these satellites.

This receiving station will offer 2 advantages :

• It will increase the number of images taken of the region through access to SPOT and ENVISAT satellite data.
• It will also increase the probability of having images which are not limited by cloud cover

The role of CNES

As a partner in the SEAS project, CNES/CSG will contribute its experience in setting up infrastructures and its technical know-how in operating receiving stations. In practical terms, CNES has allowed the antenna to be set up on its site at Montabo. The operation began with the building of the infrastructures necessary for the 4.50 m antenna along with units for operational acquisition, cataloguing and processing. These facilities need to be able to acquire, process and distribute data from the sensors carried on the SPOT 4, 5 and ENVISAT satellites.

CNES/CSG also finances 75% of the installation costs of the station because the SEAS project is perfectly in line with CNES/CSG objectives concerning :

• the installation of the receiving station,
• bringing in new public and private partners to create and run the station,
• creating favourable conditions for university courses and innovative business start-ups.