Evaluating ALOS-PALSAR for Ice Monitoring - What Can L-band do for the North American Ice Service?

Abstract

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.

Improving Sea Ice Characterization in Dry Ice Winter Conditions Using Polarimetric Parameters from C- and L-Band SAR Data

“…The ALOS-2 images on the other hand (Figure 6b,c) show a lot more OI in the FYI section compared to the sea ice chart. With its higher penetration depth, the L-band signal detects more internal structures within the more malleable FYI [10]. In order to assess the potential error of OI detection in FYI areas, the previously trained RF classifiers which were used to classify the 5 April and 28 April ALOS-2 images were reapplied on the SPAN and H parameters of the ALOS-2 image over Hudson Bay (Figure 1) and results are shown in Figure 6d.…”

“…Most of the early sea ice classification studies were conducted using single polarized C-band SAR data from ERS-1 [2][3][4][5], ERS-2 [6][7][8] and RADARSAT-1 [1,[8][9][10][11]] SAR systems. The first multifrequency fully polarimetric SAR measurements over sea ice were airborne SAR data acquired in 1988 and introduced in [12].…”

XuelongNavigation in Fast Ice Near the Zhongshan Station, Antarctica

“…Both optical and microwave remotely sensed data, for example, advanced very-high-resolution radiometer, Landsat, Moderate Resolution Imaging Spectroradiometer Onboard Terra and Auqa (MODIS), Advanced Microwave Scanning Radiometer-EOS, Envisat, and Radarsat (Arkett et al, 2008;Cavalieri et al, 2006;Kern et al, 2007;Lythe et al, 1999;Ochilov & Clausi, 2012;Ramsay, 1998;Scheuchl et al, 2001;Spreen et al, 2008), have been used to identify sea ice and subsequently used to produce sea ice concentration maps. Both optical and microwave remotely sensed data, for example, advanced very-high-resolution radiometer, Landsat, Moderate Resolution Imaging Spectroradiometer Onboard Terra and Auqa (MODIS), Advanced Microwave Scanning Radiometer-EOS, Envisat, and Radarsat (Arkett et al, 2008;Cavalieri et al, 2006;Kern et al, 2007;Lythe et al, 1999;Ochilov & Clausi, 2012;Ramsay, 1998;Scheuchl et al, 2001;Spreen et al, 2008), have been used to identify sea ice and subsequently used to produce sea ice concentration maps.…”

Towards Operational Sea Ice Type Retrieval Using L-Band Synthetic Aperture Radar

“…[1] into it's usability for operational services. Multiple studies have shown that L-band SAR can provide better contrast between different sea ice types and can provide complimentary information [1,2], such as detecting and separating deformed sea ice from the surrounding sea ice [2] and provide easier separation between first year ice (FYI) and multi-year ice (MYI) in the early and advanced melt season [2]. It was reported by [3] that L-band SAR could separate MYI among second year ice (SYI) during dry ice winter conditions.…”