| Wave Mode Polar View | |
The ENVISAT ASAR sensor in Wave Mode acquires small imagettes (5 km by 5 km to 10 km by 5 km size, high-resolution complex images of ocean scenes), allowing data acquisition to occur periodically (every 100km) around a full orbit. This constitutes the level 0 product, which is systematically produced for all data acquired within this mode.
These are processed to derive the spectra of the surface backscatter, and consequently the wavelength and the direction of the ocean waves.
ENVISAT ASAR has two level 1 products and one level 2 product:
ASA_WVI_1P: The product can contain up to 400 SLC
imagettes, each 10 km x 10 km in size, which are acquired every 100 km.
The imagettes are 1 look in azimuth and 1 look in range. The WVI product also contains the Cross Spectra of the
imagettes.
ASA_WVS_1P: This product contains the Cross Spectra of the
imagettes.
ASA_WVW_2P: This product contains the Wave Spectra.
The Cross Spectra is a polar grid of complex data with 24 bins in wavelength and 36 bins in direction (each 10 degrees wide).
The Polar View is used for displaying Cross Spectra and Wave Spectra from ENVISAT ASAR Wave mode products.
The
Polar View shows one record at a time. You may use the buttons and
slider at the bottom of the view to change the currently viewed record.
The Animate button allows the view to cycle through records
automatically.
Readouts for Peak Direction and Wavelength,
Min/Max Spectrum and Wind Speed and Direction can be viewed on the
right hand side of the polar plot.
Cursor readouts for
Wavelength, Direction and Value can be viewed on the left hand side of
the polar plot as you move your mouse over each bin.
For more information on ASAR Wave mode products:
ASAR Product Handbook – Chapter 2 - ASAR Products and Algorithms
http://envisat.esa.int/handbooks/asar/CNTR2-6.htm#eph.asar.prodalg.levb