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….?