As of january 2012, it turns out that this IKONOS data,
and the Oahu WV2 data as well,
were "offset" by an unknown amount:
"the band images after subtracting an estimate of the deep water upwelling radiance".
This interferes with my deglinting process:
I need the original radiance, direct from data provider
2 - kauai0.zip==================
This is my working directory for po_180000_0000000
PCIDSK database is kauai0.pix see database structure
Use as is, or export to your prefered image format
Glint in the NIR band is very poorly correlated to other three bands
No beach
Raging breaking waves
Clouds
Had to use another 4SM trick : now got a quite handsome results
Water there appears to be the clearest oceanic type
Did not use those 400000 plus SHOALS depth points...
Could not estimate green wavelength other than at mid-waveband;
therefore the slope might be important in FinalZ = Tideheight + slope * Computed depth
See kauai0.pix
Depth in centimeters is in channel_32 : quite interesting
Water column corrected TCC is in channels_30_29_28 RGB
Deglinted TCC is in channels_26_25_24
Results are noisy as a result of choppy seas and sturdy glint
Raw image, true color composite
is in channels_3_2_1
|
Raw image, true color composite: zoom
is in channels_26_25_24
|
image_Z250
is in channel_8 |
image_ZG in centimeters
is in channel_32 |
Source Image ID: 2004042821282980000011610601
Product Image ID: 000 Sensor: IKONOS-2 Acquired Nominal GSD Cross Scan: 0.82 meters Along Scan: 0.82 meters Scan Azimuth: 179.98 degrees Scan Direction: Reverse Panchromatic TDI Mode: 13 Nominal Collection Azimuth: 146.6109 degrees Nominal Collection Elevation: 84.38902 degrees Sun Angle Azimuth: 111.7189 degrees Sun Angle Elevation: 72.15586 degrees Acquisition Date/Time: 2004-04-28 21:28 GMT Percent Cloud Cover: 27 |
image LBS TCC
is in channels_30_29_28
|
Calibration
Not for a beginner! Hard to see through, as there may not be any bright sand around Oceanic I type of water is a sensible statement. Impossible to investigate the question of wavelength for the green band : wavelengths at mid wavebands for all four bands NO FIELD DATA USED YET |
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Here it can be seen that the glint correlations are lousy, to say the least skyglint, sunglint, and white caps : for interesting clues, please refer to US patent by Abileah ![]() |
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Kauai USACE LIDAR coverage ![]() |
Kauai image coverage |
Maui USACE LIDAR coverage ![]() |
Oahu USACE LIDAR coverage ![]() |
po_180000_0010000
This is an enormous amount of glint : can't be removed to satisfaction
It turns out that this data was "offset" by an unknown amount: I need the original radiance, direct from data provider