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RESUMEBien que Ie potentiel de detection des icebergs ait augmente considerablement au cours des dernieres decennies, la surveillance et la detection des icebergs presentent des limitations qui representent toujours un obstacle a la securite et a I 'efficacite des operations maritimes. Le transport maritime transatlantique est soumis a des detours significatifs vers Ie sud durant la saison des glaces et les installations et les procedures de production petroliere au large doivent eire concues specifiquement pour operation dans les eaux ou les icebergs sont presents incluant Ie recours ades navires additionnels dedies ala "gestion des icebergs ". Ainsi, des efforts considerables sont orientes vers Ie developpement d 'outils de teledetection pour la detection plus flable et dans toutes les conditions meteorologiques des icebergs. Le radar asynthese d'ouverture (RSO) de RADARSAT-I permet d 'accroitre de facon substantielle la frequence et la precision de la detection des icebergs. Cet article presente des resultats obtenus dans Ie cadre de I 'etude de validation pour determiner Ie potentiel de RADARSAT-I dans la detection des icebergs realisee au cours de I 'annee 2000 sur la cote est du Canada. Des images en mode faisceau large 2 et 3 et ScanSAR en mode B etroit ont ete acquises adifferents endroits pres des cotes et au large de Terre-Neuve durant les mois de mai et juin. Des donnees de realite de terrain relatives aux icebergs, basees principalement sur I 'utilisation de la photographie aerienne aechelle, ont ete acquises parallelement aux acquisitions RADARSAT-I. Les positions des icebergs derivees de la realite de terrain ont ete correlees avec les localisations de cibles dans les images RADARSAT-I et les caracteristiques des signatures des icebergs aI'interieur des images RSO ont ete documentees. Des techniques de taux de fausses alarmes constant (TFAC) ont ete utilisees pour determiner de facon empirique la probabilite de detection des icebergs en tant que fonction de la dimension de I 'iceberg, de la vitesse du vent et de I 'angle d'incidence du radar. Pour les angles RSO plus grands que 35 degres, on peut generalement detecter les icebergs d 'une dimension de I'ordre de la resolution du mode RSO utilise. Quant aux icebergs plus grands, il est possible de les detecter de facon plus constante et meme dans des conditions de mer agitee. SUMMARYThough iceberg detection capability has increased considerably over the past several decades, surveillance and detection limitations still present an obstacle to the safety and ejJiciency of marine operations. Transatlantic shipping incurs significant southerly detours during the ice season and offihore oil production facilities and procedures must be specially designed for operation in icebergfrequented waters, including additional ships dedicated to iceberg "management". As a result, considerable effort has been expended in the development of various remote sensing toolsfor reliable, all-weather detection oficebergs. The RADARSAT-l synthetic aperture radar (SAR) satellit...

The Canadian Ice Service (CIS), the U.S. National Ice Center (NIC), and the International Ice Patrol (IIP), partners in the North American Ice Service (NAIS), have individually and jointly used airborne and spaceborne synthetic aperture radar data extensively for almost three decades in their daily ice monitoring operations. SAR's unique ability to penetrate clouds and weather make these data invaluable to the NAIS' efficient environmental stewardship and safe operation in Canadian and U.S. waters. Since 1992, solely C-Band satellite radar has been in use as operational SAR missions such as ERS 1 & 2, RADARSAT-1, and Envisat ASAR have selected it as the band of choice. With the launch of RADARSAT-2 on December 2007 and approved plans for Sentinel-1, the NAIS intends to continue utilizing C-Band data in its daily operations. However, it is important to understand the unique and complementary capabilities of other SAR bands. The January 2006 launch of the JAXA ALOS satellite and present availability of L-band SAR data from its PALSAR instrument provides a unique opportunity to assess L-band data for application to ice monitoring. ALOS/PALSAR availability also provides the potential for examining the synergies between L-Band data and C-Band data available from the current and planned C-Band missions. The existing literature suggests that the use of different frequencies could be advantageous in certain ice conditions, which is of interest to the NAIS because of the vastness of the geographical area monitored annually and the associated variations in ice regimes and conditions. This paper summarizes the preliminary results of a NAIS evaluation of near-coincident C-Band (RADARSAT-1) and L-Band data sets collected in various ice regimes. Through both quantitative and qualitative analysis we attempt to identify the unique and complementary sea ice information PALSAR can provide. In doing so, we identify the role these data could play in the NAIS' operational programs, both in a complementary role to existing C-Band SARs and its potential as a contingency platform. This work will also help us better understand the potential for future possible multi-frequency SAR platforms.

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