12 Towards Operational Monitoring of Arctic Sea Ice by SAR
277
The demonstration proved a key learning experience, not without problems as can be
seen, which enabled a strong view to be taken of the requirements for an operational
system. These can be listed as follows:
Product requirements
- Coverage of greater than 200 x 200 km (ideally more), without major gaps
- Update frequency between 12 hand 72 h (depending on operations)
- Appropriate pricing structure, based on subscription
- Relatively small file size to aid transmission times and memory requirements
- Flexibility in algorithms and scope for manual intervention
Transmission requirements
- Product delay under 4 h (SAR acquisition to product reception). Implies broad bandwidth link
- Digital reception at destination
- Transmission of other relevant information (e.g. meteorological data) via the same
program, preferably from a single bulletin board source
On-board manipulation
- Coregistration of different products and ingestion of shipborne information (position, bearing, marine radar, meteorological products, AVHRR-derived ice charts,
etc.)
- Facility to display coverage of new products as a means of selecting and ordering new
products.
Meeting these requirements is a basic prerequisite for the routine use of spaceborne
SAR in tactical ice monitoring. To integrate spaceborne SAR data firmly within the infrastructure of ice monitoring will require cooperation from existing meteorological and
ice services, who will themselves be best placed to provide the bulletin board for ice
products and to convince the end users of the value of the data.
Ongoing activities with the IPAP system include installation of the software at the
Defence Research Agency Farnborough for evaluation in Royal Navy trials using
ERS-2 SAR data (in "strip mode" format) towards the end of 1996. However, it is
important to note that the IPAP system has been developed primarily as a flexible
research tool to support algorithm research and development, rather than as a dedicated operational workstation running in near to real-time and with the minimum
of operator intervention. The commercial viability of such a system has to date also
been seriously limited by the constraints put on the operator requirements given in
Sect. 12.1 by the use of ERS-l data. The most important recent development in the
capability of satellite SAR systems for sea ice observation has been the launch in
1995 of RADARSAT, a C-band HH polarization SAR with the ability to collect data
over a number of variable incidence angles (20 0
-
50 0
)
and swath widths (50 - 500
km), at a variable resolution of 30 - 100 m. This degree of flexibility with a nominal
repeat period of 24 days greatly enhances the sensor's coverage and thus its operational utility. It is intended to adapt the IPAP system to handle RADARSAT data at
a future date.
277
The demonstration proved a key learning experience, not without problems as can be
seen, which enabled a strong view to be taken of the requirements for an operational
system. These can be listed as follows:
Product requirements
- Coverage of greater than 200 x 200 km (ideally more), without major gaps
- Update frequency between 12 hand 72 h (depending on operations)
- Appropriate pricing structure, based on subscription
- Relatively small file size to aid transmission times and memory requirements
- Flexibility in algorithms and scope for manual intervention
Transmission requirements
- Product delay under 4 h (SAR acquisition to product reception). Implies broad bandwidth link
- Digital reception at destination
- Transmission of other relevant information (e.g. meteorological data) via the same
program, preferably from a single bulletin board source
On-board manipulation
- Coregistration of different products and ingestion of shipborne information (position, bearing, marine radar, meteorological products, AVHRR-derived ice charts,
etc.)
- Facility to display coverage of new products as a means of selecting and ordering new
products.
Meeting these requirements is a basic prerequisite for the routine use of spaceborne
SAR in tactical ice monitoring. To integrate spaceborne SAR data firmly within the infrastructure of ice monitoring will require cooperation from existing meteorological and
ice services, who will themselves be best placed to provide the bulletin board for ice
products and to convince the end users of the value of the data.
Ongoing activities with the IPAP system include installation of the software at the
Defence Research Agency Farnborough for evaluation in Royal Navy trials using
ERS-2 SAR data (in "strip mode" format) towards the end of 1996. However, it is
important to note that the IPAP system has been developed primarily as a flexible
research tool to support algorithm research and development, rather than as a dedicated operational workstation running in near to real-time and with the minimum
of operator intervention. The commercial viability of such a system has to date also
been seriously limited by the constraints put on the operator requirements given in
Sect. 12.1 by the use of ERS-l data. The most important recent development in the
capability of satellite SAR systems for sea ice observation has been the launch in
1995 of RADARSAT, a C-band HH polarization SAR with the ability to collect data
over a number of variable incidence angles (20 0
-
50 0
)
and swath widths (50 - 500
km), at a variable resolution of 30 - 100 m. This degree of flexibility with a nominal
repeat period of 24 days greatly enhances the sensor's coverage and thus its operational utility. It is intended to adapt the IPAP system to handle RADARSAT data at
a future date.