Data set specification

The "World Estuary" is the collection of the full-resolution Level 1B. OCTS data for the 17 big river estuaries in the world. "Case II water" often appears in big river estuaries where active ocean-biological process occur. The process is so complicated that there exists no universal algorithm = to retrieve phytoplankton, yellow substances, and suspended material from ocean color data. The data set has been compiled as a test bed to develop new algorithms = for the Case II water.

1.Directory Configuration:

Data will be housed by subdirectory and by river as follows:

dir_name	river name	Regions = (estuaries)
amzn	the Amazon	Brazil
amur	the Amur	Russia (Tatar Strait)
colo	the Colorado	USA (Gulf of = California)
dnub	the Danube	Romania
gngs	the Ganges	Bangladesh
yelw	the Huang He	China
mkng	the Mekong	Viet Nam
murr	the Murray	Australia
miss	the Mississippi	USA (Gulf of = Mexico)
nigr	the Niger	Nigeria
nile	the Nile	Egypt
lplt	the Rio de la Plata	Argentina
lwrn	the St. Lawrence	Canada
volg	the Volga	Russia (Caspian Sea)
yngz	the Yangtze Kiang	China
zmbz	the Zambezi	Mozambique

2. Files in a directory

Data is stored in Big-endian byte order.

	*.029	: Cut-out image data file = (OCTS, LAC, Level 1B, Band 1)
	*.031	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 2)
	*.033	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 3)
	*.035	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 4)
	*.037	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 5)
	*.039	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 6)
	*.041	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 7)
	*.043	: Cut-out image data file (OCTS, LAC, = Level 1B, Band 8)

	*.inf	: Cut-out position data = file
	*.atr	: Attribute data file
	*.anc	: Ancillary data file
	*.tif	: Image browse (Band 6 : Band 5 : Band = 3 =3D Red : Green : Blue)
	*.lat	: Latitude @ each pixel for Cut-out = image
	*.lon	: Longitude @ each pixel for Cut-out = image
	*.saz	: Satellite zenith angle @ each pixel = for Cut-out image
	*.saa	: Satellite azimuth angle @ each pixel = for Cut-out image
	*.soz	: Solar zenith angle @ each pixel for = Cut-out image
	*.soa	: Solar azimuth angle @ each pixel for = Cut-out image

3. File Description

1. Cut-out image data file (*.029 - 043) in 16bit INT

This is the image data which cover 501x 501 pixel regions with estuaries, that were cut-out from the Level 1B image data of LAC, OCTS. The cut-out position of each eight bands is the same, but files are provided for each 8 visible and near infrared bands. Each pixel is 16 bits and the first 3 bits of flag information are masked by "0".
DN can be translate to radiance by using linear equation. The equation and coefficients are in section 4 in this file.

2. Geolocation files (*.lat, lon, saz, saa, soz, soa) in 16bit INT

Latitude, Longitude, Satellite zenith angle, Satellite azimuth angle, Solar zenith angle and Solar azimuth angle, respectively are kept in each pixel(size of 501 x 501). This geolocational information is calculated from scanline attribute in original file.
All this information is stored in 16bit integer (DN). Order of the DN storage is as following.

integer*2 geoDN(501,501)
((geoDN(pixel,line),pixel=1,501),line=1,501)

"geoDN" will be read from each of Geolocation files.
Each parameter will be given by multiply by factor of 0.01 (slope).

slope=0.01
geo_float(pixel,line) = geoDN(pixel,line)*slope

unit of geo_float = [degree]

where, geo_float(pixel,line) can be Latitude, Longitude, Satellite zenith angle, Satellite azimuth angle, Solar zenith angle and Solar azimuth angle.


3. Cut-out position data file (*.inf) in ASCII

This is the file of the data that indicate relative positions of Level 1B image data of LAC, OCTS and cut-out from that image data.

	Scene Center Address in Column
	Scene Center Address in Scan-Line
	Width from Scene Center in Column
	Height from Scene Center in Scan-line
	Scene Center Latitude
	Scene Center Longitude
	Upper Left Latitude
	Upper Left Longitude
	Upper Right Latitude
	Upper Left Longitude
	Lower Left Latitude
	Lower Left Longitude
	Lower Right Latitude
	Lower Right Longitude



4. Attribute data file (*.atr) in ASCII

The attribute data file consists of Global Attribute that is added to the Level 1B data. The format of Ancillary data file is described after the Ancillary data file. The description part begins from "Ancillary File including following..." and each parameters describe as follows.

#3 ; msec	....... tag name
Data_type= INT32	....... type of the data
Rank = 1	....... rank of dimension
Dimsize[0]= 560	....... size of the dimension

If you need to read the ancillary data file, please refer this description.

5. Ancillary data file (*.anc) in Binary

This file contains all the data from the original L1b except L1b data part (channel data) and global attribute. This information is for original size of data. This means information in this file are NOT corresponds to the cut-out size (501 x 501).
Please refer Attribute data file for format of this file.

6. Image browse (*.tif) in binary

This is the image file of TIFF format, in which Bands 6, 5 and 3 of cut-out image data file are converted into red, green and blue each.

4. Calibration factor for L1b radiance

L1b radiance for each band can be derived from ,

L1b_rad0(band) = DN(band)*Slope(band)
L1b_rad(band) = L1b_rad0(band) * correction_factor(band)

units of L1b_rad = [mW cm^-2 um^-1 sr^-1]

Please refer the following table for the slopes and correction factors for each bands .

OCTS band		1	2	3	4	5	6	7	8
Slope		0.004148	0.004080	0.003423	0.003043	0.002376	0.001521	0.001030	0.0005008
Correction factor	Version 41	1.14	1.03	0.939	1.00	1.04	1.00	1.02	0.89
	SIMBIOS2	1.13	1.01	0.94	1.00	1.03	0.99	0.91	0.89

5. References

1. Shimada, M., H. Oaku, Y. Mitomi, H. Murakami, and H. Kawamura,
Calibration of the Ocean Color and Temperature Scanner, IEEE Trans. Geosci. Remote Sensing,
37, 1484-1495, 1999.

2. Fargion, G. S., C. R. McClain, H. Fukushima, J. M. Nicolas, and R. A. Barnes,
"Ocean Color Instrument Intercomparisons and Cross-calibrations by the SIMBIOS Project",
EOS/SPIE Symposium on Remote Sensing, 20-24 September 1999.

6. Contact point

e-mail :

Harumi Island Triton Square Office Tower X 23F
1-8-10 Harumi, Chuo-ku, Tokyo 104-6023 Japan
Phone +81-3-6221-9090 Fax +91-3-6221-9191

Earth Observation Research Center Last Update: 29 March 2002

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