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Exercise 1: Spiraling Hurricane Katrina from cloud tops to ocean waves
Acquisition locations for Envisat's MERIS and ASAR images
Chart showing acquisition locations for Envisat's MERIS and ASAR images

The purpose of this exercise is to gain familiarity with two different instruments onboard Envisat: the Medium Resolution Imaging Spectrometer (MERIS) and the Advanced Synthetic Aperture Radar (ASAR). You will become acquainted with their potential fields of application and some of their general technical characteristics.
In the data zipfile on the right, you will find an Envisat MERIS image in reduced resolution mode of a large part of the Gulf of Mexico. The image was acquired on 28 August 2005, at 15:50 UTC. The data contain all 15 channels:




Channel Number
Centre Wavelength / 

Bandwidth (nm)
1412.5 (purple) / 10Yellow substance and detrial pigments
2442.5 (blue) / 10Chlorophyll absorption maximum
3490 (blue-cyan) / 10Chlorophyll and other pigments
4510 (cyan-green) / 10Suspended sediment, red tide
5560 (green) / 10Chlorophyll absorption minimum
6620 (orange-red) / 10Suspended sediment
7665 (red) / 10Chlorophyll absorption and fluorescence reference
8681.25 (red) / 7.5Chlorophyll fluorescence peak
9708.75 (NIR) / 10Fluorescence reference, atmospheric corrections
10753.75 (NIR / 7.5Vegetation, cloud
11760.625 (NIR) / 3.75Oxygen absorption R-branch
12778.75 (NIR) / 15Atmosphere corrections
13865 (NIR) / 20Vegetation, water vapour reference
14885 (NIR) / 10Atmosphere corrections
15900 (NIR) / 10Water vapour, land
The MERIS sensor’s spectral characteristics found in the table above will be helpful for all of the tasks you will be asked to perform regarding the MERIS image.

In the zip file you will also find an ASAR image in Wide Swath mode acquired on 28 August 2005. By piercing through the clouds of Hurricane Katrina, the ASAR image displays a section of the Gulf of Mexico and shows the shape of the wind-driven sea surface.



Storm surges
Hurricane Katrina
Exercise 2: Visualising and examining flooded areas in New Orleans caused by Hurricane Katrina
Eduspace - Software
LEOWorks 3
Eduspace - Download
Envisat and SPOT data (zip)
Related links
Hurricane Katrina - NOAAHurricane Katrina - WikipediaNational Hurricane Center - NOAAStorm surge overview - NOAAGlobal Monitoring for Environment and Security - ESAInternational Charter Space and Major DisastersTropical weather and hurricanes - Physicalgeography
Related news
Envisat sees whirling Hurricane Katrina from ocean waves to cloud tops
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