Rice monitoring and production estimation using multitemporal RADARSAT

Observations from spaceborne radar contain considerable information about vegetation dynamics. The ability to extract this information could lead to improved soil moisture retrievals and the increased capacity to monitor vegetation phenology and water stress using radar data. The purpose of this review paper is to provide an overview of the current state of knowledge with respect to backscatter from vegetated (agricultural) landscapes and to identify opportunities and challenges in this domain. Much of our understanding of vegetation backscatter from agricultural canopies stems from SAR studies to perform field-scale classification and monitoring. Hence, SAR applications, theory, and applications are considered here too. An overview will be provided of the knowledge generated from ground-based and airborne experimental campaigns that contributed to the development of crop classification, crop monitoring, and soil moisture monitoring applications. A description of the current vegetation modeling approaches will be given. A review of current applications of spaceborne radar will be used to illustrate the current state of the art in terms of data utilization. Finally, emerging applications, opportunities and challenges will be identified and discussed. Improved representation of vegetation phenology and water dynamics will be identified as essential to improve soil moisture retrievals, crop monitoring, and for the development of emerging drought/water stress applications.

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Radar Remote Sensing of Agricultural Canopies: A Review

According to the 1993 colloquium on the ‘Global status of coral reefs', our understanding of the global role of coral reefs is inadequate. To increase our understanding, an accurate large-scale mapping and monitoring programme is necessary. Historically, coastal zones have been mapped using traditional surveying tools such as topographic maps, nautical charts, existing aerial photographs and direct observations. Although less expensive than digital imagery, exclusive use of these traditional tools may not be practical for monitoring large or remote coral reef ecosystems accurately. Researchers are attempting to develop an adequate coral reef mapping system based on digital remote sensing, but are impeded by issues such as effects of the intervening water column and spectral distinction of bottom types. The two variables discussed, which will contribute to our understanding of the global role of coral reefs, are: 1) remote sensing of submerged coral reefs in general; and 2) remote sensing of coral bleachin...

The scientific issues surrounding remote detection of submerged coral ecosystems

RESUMEAvec le lancement de plusieurs radars a antenne synthetique (RAAS) au cours des annees 90, il apparait certain que l'on disposera alors de donnees radar multidates pour des applications en agriculture. Il est necessaire toutefois de poursuivre les recherches afin d'utiliser cette technologie efficacement et de rendre pratique l'utilisation de donnees microondes dans les systemes d'information sur les cultures existants. Le CCT utilise actuellement des plates-formes terrestres ainsi que des plates-formes aeroportees a cette fin. Une serie de donnees multidates sur des cultures de ble de printemps (barbele et non barbele), d'orge, de canola et de terres en jachere, recueillie par un scatterometre au sol dans la bande Ku, Cet L, a ete etudiee en fonction de l'information qu 'elles peuvent fournir quant a la discrimination des cultures. Les rapports F ont ete calcules, puis classifies en vue d'evaluer les effets produits par la frequence, la polarisation et l'angle d'incidence sur la discrimination des ...

Temporal ground-based scatterometer observations of crops in Western Canada

La capacite d'acquerir des images au travers les nuages ou la nuit rend les capteurs radar tres utiles pour diverses applications. Lors de la derniere decennie, on a assiste a une explosion dans le developpement de la technologie et des applications des donnees radars satellitaires a des fins civiles. L'une de ces initiatives est RADARSAT, un satellite canadien a vocation commerciale dote d'un capteur radar a synthese d'ouverture (RSO). Pour stimuler l'utilisation des donnees RADARSAT a l'echelle internationale, le programme GlobeSAR fut mis sur pied en 1993. Le but de ce programme etait le transfert de technologie et de developpement des ressources humaines dans des pays en voie de developpement dans le domaine des applications du RSO. La possibilite pour l'usager de choisir le mode d'acquisition de RADARSAT se traduit cependant par un niveau de complexite plus eleve lors de la commande et du choix des images. Un compromis est alors necessaire entre couverture spatiale, resolution, nombre de visees et angle d'incidence lors de la commande, du traitement et de l'analyse des donnees. Cet article passe en revue quelques applications menees sous l'egide du programme GlobeSAR et fait des recommendations preliminaires pour le choix du mode d'acquisition optimal en fonction de l'application. On y traite aussi de l'utilisation de donnees auxiliaires pour complementer celles du RSO. Finalement, on presente quelques images RADARSAT pour appuyer les resultats.

RADARSAT Applications: Review of GlobeSAR Program

This paper outlines the evolution, goals and general accomplishments to date of the GlobeSAR Project. The project involves an international airborne data acquisition campaign with the Canada Centre for Remote Sensing's C/X airborne radar system. Data have been provided to cooperating countries as both airborne imagery and as simulations of Canada's RADARSAT to be launched in 1995. As part of the project there have been a number of workshops, on‐going research projects, and a significant technology transfer and technology provision activity. Participating countries include China, Jordan, Kenya, Malaysia, Morocco, Tanzania, Thailand, Tunisia, Uganda, and Viet Nam.

GlobeSAR: A Canadian radar remote sensing program

Microwave imaging systems hold great promise of meeting one of the most important requirements of data for vegetation monitoring ‐ namely data timeliness. Furthermore, synthetic aperture radar (SAR) imagery will be routinely available within the near future with the launches of the European Space Agency, (1990), Japanese (1991) and Canadian RADARSAT (1994) satellites. Within Canada, there is an extensive program underway (Radar Data Development Program ‐ RDDP) to develop the necessary methodologies to use SAR data for renewable resource management. This program includes data acquisition using both airborne SAR imagery and ground‐based scatterometers. This paper describes this RDDP program in some detail and presents some pertinent results attained to date.

Preparing for satellite microwave systems for renewable resource management

The GlobeSAR program is designed to develop RADARSAT applications in Asia, the Middle‐East, and Africa and to help prepare the scientists and end‐users in the participating countries for using RADARSAT data to meet their various needs. A collaborative approach involving the participants from each country and a team of Canadian experts has been studying the airborne SAR data and the RADARSAT simulations for a variety of applications. This paper reviews the most promising results obtained during the first phase of the GlobeSAR program for the countries in Southeast Asia.

R.J. Brown

Papers

GlobeSAR: A Canadian radar remote sensing program

Preparing for satellite microwave systems for renewable resource management

GlobeSAR applications review