R.KwOK
11.5
Summary and Discussion
We have described the sea ice algorithms that are used to generate the RGPS data products. The processing system described here serves three purposes: (1) to transform values of radar backscatter into fields of information that are useful for scientists; (2) to
analyze images consistently, so that comparisons can be made over wide spatial and temporal scales without biases due to processing; and (3) to handle large volumes of data.
The RGPS algorithms give us an opportunity to estimate sea ice parameters (ice
age/thickness) previously inaccessible using other data sets. The potential payoffs in geophysical understanding of the polar regions will be very large if the radar coverage and
data quality allow us routinely to make basin-scale observations of the Arctic Ocean.
In April of 1994, an RGPS Working Group was established to define the geophysical
variables which could be routinely extracted from the RADARSAT SAR data, to specify the data products, and to monitor the implementation process and the evolution of
the system. The current membership of this group contributes directly to the development of the analysis algorithms and definition of the data products. This group is also
responsible for the verification of the system, the validation of the data products, and
processing strategy. We define verification as the process used to confirm that the system and procedures work as designed and validation as the test of the scientific validity of the products. After the initial release of RGPS data products, we envisage a larger working group which includes participation of the broader user community to facilitate exchange of information and ideas amongst users of the products.
At the time of this writing (June 1996), the RADARSAT commissioning phase activities are drawing to a close. These activities include the checkout of the space segment
and ground segment, and the calibration of the RADARSAT beams. The release of the
SAR data for RGPS analysis will be available shortly thereafter. Based on the current
schedule, the implementation of RGPS will be completed in October of 1997. This is followed by a 6-month verification phase, for assessment of the performance of the system and verification of the algorithms, after which the system will start routine processing of the Arctic Ocean data.
Acknowledgments. R. Kwok performed this work at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space
Administration.
References
Barber DG, Papakyriakou TN, LeDrew EF (1994) On the relationship between energy
fluxes, dielectric properties, and microwave scattering over snow covered first-year
ice during the spring transition period. J Geophys Res 99, no C11: 22401-22411
Cavalieri DJ, Gloersen P, Campbell WJ (1984) Determination of sea ice parameters from
Nimbus 7 SMMR. J Geophys Res 89, no D4: 5355-5369
Comiso JC, Kwok R (1996) Surface and radiative characteristics of the summer Arctic
sea ice cover from multisensor satellite observations. J Geophys Res 101, no
C12:28397-28416
11.5
Summary and Discussion
We have described the sea ice algorithms that are used to generate the RGPS data products. The processing system described here serves three purposes: (1) to transform values of radar backscatter into fields of information that are useful for scientists; (2) to
analyze images consistently, so that comparisons can be made over wide spatial and temporal scales without biases due to processing; and (3) to handle large volumes of data.
The RGPS algorithms give us an opportunity to estimate sea ice parameters (ice
age/thickness) previously inaccessible using other data sets. The potential payoffs in geophysical understanding of the polar regions will be very large if the radar coverage and
data quality allow us routinely to make basin-scale observations of the Arctic Ocean.
In April of 1994, an RGPS Working Group was established to define the geophysical
variables which could be routinely extracted from the RADARSAT SAR data, to specify the data products, and to monitor the implementation process and the evolution of
the system. The current membership of this group contributes directly to the development of the analysis algorithms and definition of the data products. This group is also
responsible for the verification of the system, the validation of the data products, and
processing strategy. We define verification as the process used to confirm that the system and procedures work as designed and validation as the test of the scientific validity of the products. After the initial release of RGPS data products, we envisage a larger working group which includes participation of the broader user community to facilitate exchange of information and ideas amongst users of the products.
At the time of this writing (June 1996), the RADARSAT commissioning phase activities are drawing to a close. These activities include the checkout of the space segment
and ground segment, and the calibration of the RADARSAT beams. The release of the
SAR data for RGPS analysis will be available shortly thereafter. Based on the current
schedule, the implementation of RGPS will be completed in October of 1997. This is followed by a 6-month verification phase, for assessment of the performance of the system and verification of the algorithms, after which the system will start routine processing of the Arctic Ocean data.
Acknowledgments. R. Kwok performed this work at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space
Administration.
References
Barber DG, Papakyriakou TN, LeDrew EF (1994) On the relationship between energy
fluxes, dielectric properties, and microwave scattering over snow covered first-year
ice during the spring transition period. J Geophys Res 99, no C11: 22401-22411
Cavalieri DJ, Gloersen P, Campbell WJ (1984) Determination of sea ice parameters from
Nimbus 7 SMMR. J Geophys Res 89, no D4: 5355-5369
Comiso JC, Kwok R (1996) Surface and radiative characteristics of the summer Arctic
sea ice cover from multisensor satellite observations. J Geophys Res 101, no
C12:28397-28416