9 Alaska SAR Facility: The US Science Center for Sea Ice SAR Data
199
users are now beginning to anticipate the next generation of SAR flight instruments
for future strengthening of their programs and data products. If international agreements allow, there will be significant benefits to the US in the utilization of the
planned SAR data coverage of the continental US and EEZ and the polar regions.
These benefits accrue in operations, development, science, and technology assessment. Areas of probable benefit include ship operations in lake, sea, and river ice,
coastal processes and monitoring, flooding, agriculture, meteorology and severe
weather, hydrology, wild-fire monitoring, fishery research and management, and
allied areas.
Notable among the SAR flights of the future are the European ENVISAT satellite flying Advanced SAR in 1998 or 1999 and the Japanese ALOS flying in 2002; in each case
the instruments flown have the same carrier wavelength as their antecedents - C-band
for ESA and L-band for NASDA - with augmented capabilities. These SAR systems of
the future offer valuable opportunities for US SAR users in science, applications, and
operations. Consequently a national review is required of the purposes to which these
future data streams could be put, the requirements imposed by these purposes, the technological maturity of the user communities, the cost implications in providing data
products, and a general approach to meeting user needs in a timely and cost-effective
means. ASF would support such a review.
The ESA instrument,Advanced SAR (ASAR) on ENVISAT, will fly soon. ASAR is a Cband SAR with variable incidence angle, selectable polarization, and an intriguing
wide-swath, low-resolution mode which is planned to be operational whenever no other mode is operational. That is, ENVISAT ASAR will always be "on:' and coverage of a
survey nature essentially routinely available, analogous to the data stream from the
NOAA Polar Orbiter series. For either scientific or operational sea ice data needs,
ENVISAT coverage becomes a highly plannable resource. ASAR is expected to be of
greatest interest in oceanography and sea and lake ice observations; the use of these
data in coastal research and operations is particularly promising.
The ALOS now under development by NASDA carries a fully polarimetric L-band
SAR called VSAR (see Table 1). Its longer wavelength will result in applications involving volume scattering, and its polarimetric data will provide an excellent description
of ice type and possibly even ice thickness of first-year ice (Drinkwater 1995). Hence
land processes will be the key application of ALOS, but sea ice application will be
included.
In the immediate future ASF will participate in higher-level data products in two ways:
in RGPS operation and in the support of user software. It is the objective of ASF to
enlarge that portfolio in ways consistent with the overall ASF mission and vision, and
to support higher-level data production at other institutions whenever possible and
appropriate, e.g., by supplying SAR images to the RADARSAT Antarctic Mapping Project at Ohio State University.
ASF and its associated McMurdo reception station are poised to serve the sea ice science and operations communities with SAR image and higher-level data products for
the foreseeable future. The use of the data products in the past has been directed at
some of the key problems in polar ocean surface process determinations by researchers
across the US and in other countries.ASF is a national resource in this area; the science
and operations communities should continue to utilize its capabilities and place
demands on its resources.
199
users are now beginning to anticipate the next generation of SAR flight instruments
for future strengthening of their programs and data products. If international agreements allow, there will be significant benefits to the US in the utilization of the
planned SAR data coverage of the continental US and EEZ and the polar regions.
These benefits accrue in operations, development, science, and technology assessment. Areas of probable benefit include ship operations in lake, sea, and river ice,
coastal processes and monitoring, flooding, agriculture, meteorology and severe
weather, hydrology, wild-fire monitoring, fishery research and management, and
allied areas.
Notable among the SAR flights of the future are the European ENVISAT satellite flying Advanced SAR in 1998 or 1999 and the Japanese ALOS flying in 2002; in each case
the instruments flown have the same carrier wavelength as their antecedents - C-band
for ESA and L-band for NASDA - with augmented capabilities. These SAR systems of
the future offer valuable opportunities for US SAR users in science, applications, and
operations. Consequently a national review is required of the purposes to which these
future data streams could be put, the requirements imposed by these purposes, the technological maturity of the user communities, the cost implications in providing data
products, and a general approach to meeting user needs in a timely and cost-effective
means. ASF would support such a review.
The ESA instrument,Advanced SAR (ASAR) on ENVISAT, will fly soon. ASAR is a Cband SAR with variable incidence angle, selectable polarization, and an intriguing
wide-swath, low-resolution mode which is planned to be operational whenever no other mode is operational. That is, ENVISAT ASAR will always be "on:' and coverage of a
survey nature essentially routinely available, analogous to the data stream from the
NOAA Polar Orbiter series. For either scientific or operational sea ice data needs,
ENVISAT coverage becomes a highly plannable resource. ASAR is expected to be of
greatest interest in oceanography and sea and lake ice observations; the use of these
data in coastal research and operations is particularly promising.
The ALOS now under development by NASDA carries a fully polarimetric L-band
SAR called VSAR (see Table 1). Its longer wavelength will result in applications involving volume scattering, and its polarimetric data will provide an excellent description
of ice type and possibly even ice thickness of first-year ice (Drinkwater 1995). Hence
land processes will be the key application of ALOS, but sea ice application will be
included.
In the immediate future ASF will participate in higher-level data products in two ways:
in RGPS operation and in the support of user software. It is the objective of ASF to
enlarge that portfolio in ways consistent with the overall ASF mission and vision, and
to support higher-level data production at other institutions whenever possible and
appropriate, e.g., by supplying SAR images to the RADARSAT Antarctic Mapping Project at Ohio State University.
ASF and its associated McMurdo reception station are poised to serve the sea ice science and operations communities with SAR image and higher-level data products for
the foreseeable future. The use of the data products in the past has been directed at
some of the key problems in polar ocean surface process determinations by researchers
across the US and in other countries.ASF is a national resource in this area; the science
and operations communities should continue to utilize its capabilities and place
demands on its resources.