International Ice Charting Working Group V – Hamburg 19-23 April 2004
Operational use of ENVISAT at the Danish Meteorological Institute
Preliminary Results and Experience from the first two months
Keld Q. HansenDMI
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Why use ENVISAT?
International Ice Charting Working Group V – Hamburg 19-23 April 2004
HISTORY:
Main Operation area: Cape Farewell (all offshore & inshore routes)
February 1999:
Aircraft and helicopter as primary data source
satellite data used complementary
Test of operational use of SAR – data
Yes, IF we have SAR data from TWO satellites
OK frequency and coverage => potential skipping of poor data
the satellites can be backup for each other
Can we skip the aircraft completely?
International Ice Charting Working Group V – Hamburg 19-23 April 2004
March 1999
Radarsat primary data source for ice mapping (offshore)
Helicopter used inshore
June-July (surface melt water) : ice recco aircraft in service in combination with Radarsat
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Winter 2003/04: contract with Kongsberg Satellite Station on delivery of 250 Envisat scenes/year (= data from Tromsø and Gatineau).
The operational setup is complicated by the fact that we need direct broadcast and taped data to cover all areas of interest.
Only limited evidence of ENVISAT’s operational capability.
We decided to only use ENVISAT outside DMI primary mapping area
The launch of ENVISAT (March 2002) was expected to realize this future opportunity….. but time went by ….
Summer 2003 first ice season without ice recco aircraft BUT only ONE satellite… luckily the ice season was the lightest in 50 years
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Planning of SAR scenes:
ENVISAT: DESCW (developed by ESA)designed for multi purposesinflexible (shifting scenes is difficult)not user friendly (100’s of mouse clicks)time consuming
RADARSAT: SPA (Swath Planning Application) single purposesimpleflexiblesaves swathplans in various formats at the same time
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Statistics for SAR data received at DMI:
RADARSAT Feb04 Mar04 Apr04*Planned 45 34 18Received NRT 44 34 15
ENVISAT Feb04 Mar04 Apr04*Planned 5 14 14Received NRT 4 6 8
* Status April 16
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Experienced ENVISAT NRT Problems
Scene is cancelledexample 15th April 2004:
“Order cancelled by ESA due to conflict”. (message received 2 hours after satellite pass)
Scene is delayed
Scene does not cover 500 km
Scene is shifted north-south
International Ice Charting Working Group V – Hamburg 19-23 April 2004
ENVISAT Processing at DMI:
Image contrast / brightness have to be improved, 16 bits 8 bits
ENVISAT ASAR 12 April 2004 0028 UTC
RADARSAT SCANSAR Wide11 April 2004 2038 UTC
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Status Mid-April 2004:
Radarsat is still the primary data source in the Cape Farewell area.
Envisat complementary.
May 2004: Test of Envisat operational capability outside Cape Farewell area No Radarsat data ordered !!!!
International Ice Charting Working Group V – Hamburg 19-23 April 2004
Future…
We expect stable delivery of data to be accomplished – we need more than 95 % success rate.
We would like to reduce time from order to actual satellite pass, do anybody have experience with emergency planning ? We need to improve image contrast / brightness (DMI, ESA ?)
Continuous dialogue on faster and stable NRT delivery with the purpose of improving the service (KSAT, ESA)
We look forward to user friendly swath planning software (ESA)
Aircraft backup back up in 2004RADARSAT is an excellent backup for ENVISATENVISAT has until now NOT proved backup potential
International Ice Charting Working Group V – Hamburg 19-23 April 2004
ESA….?