28. EARLY RESULTS FROM ADEOS AND FUTURE EARTH
OBSERVATION MISSIONS
283
The sensor stability was estimated by electrical calibration, internal light
source calibration, and nighttime observation image, and it is confirmed that
OCTS is stable after the beginning of October 1996.
NASDA has calibrated the absolute radiance using the NASA airborne
sensor AVIRIS. As a result, an accuracy of 10% was achieved. Then, using
calibrated sensor input radiance and ground truth data, the algorithm was
verified and its parameters were tuned up. Moreover, NASDA is conducting
improvement of the accuracy using additional observation data.
So far, as a result of such verification, an accuracy of 50% in the
estimation of chlorophyll-a has been attained and the next version of the
algorithm is expected to improve the accuracy further. On the sea surface
temperature, the tuning of the algorithm is under way to improve the
accuracy using about 530 points from NOAA truth data. So far, OCTS SST
data is about 1.8 degrees lower than NOAA AVHRR SST data, and the
standard deviation is 0.8.
In addition, a global vegetation index map using OCTS band 6 (660-680
nm), 7 (745-785 nm) and 8 (845-885 nm) is planned to be generated.
3.1.2
AVNIR
NASDA/EORC had estimated the spatial resolution, the signal to noise
ratio and the geometric accuracy. The performance is almost meeting the
specification. On the geometric accuracy, further improvement will be made.
The calibration was made using AVIRIS data, and the parameters of
algorithm were confirmed.
3.2
Algorithm development and data sets generation
OCTS algorithm has been improved gradually. The first version was used
from the beginning of operation to 9 April 1997, and then after 10 April,
version 2 was used to process the data. Version 3 will be available by the
end of September. The image quality is also improved by the same date.
So far, 10 CD-ROMs including OCTS and AVNIR data sets were made
by EORC as a sample data for users. After this, EORC is planning to
produce data sets such as match-up data set s of satellite data and truth data
dedicated to scientific users.
3.3
Results from ADEOS observations
Using data already acquired, sensor providers have processed and
distributed data such as the chlorophyll-a concentration in the ocean,
OBSERVATION MISSIONS
283
The sensor stability was estimated by electrical calibration, internal light
source calibration, and nighttime observation image, and it is confirmed that
OCTS is stable after the beginning of October 1996.
NASDA has calibrated the absolute radiance using the NASA airborne
sensor AVIRIS. As a result, an accuracy of 10% was achieved. Then, using
calibrated sensor input radiance and ground truth data, the algorithm was
verified and its parameters were tuned up. Moreover, NASDA is conducting
improvement of the accuracy using additional observation data.
So far, as a result of such verification, an accuracy of 50% in the
estimation of chlorophyll-a has been attained and the next version of the
algorithm is expected to improve the accuracy further. On the sea surface
temperature, the tuning of the algorithm is under way to improve the
accuracy using about 530 points from NOAA truth data. So far, OCTS SST
data is about 1.8 degrees lower than NOAA AVHRR SST data, and the
standard deviation is 0.8.
In addition, a global vegetation index map using OCTS band 6 (660-680
nm), 7 (745-785 nm) and 8 (845-885 nm) is planned to be generated.
3.1.2
AVNIR
NASDA/EORC had estimated the spatial resolution, the signal to noise
ratio and the geometric accuracy. The performance is almost meeting the
specification. On the geometric accuracy, further improvement will be made.
The calibration was made using AVIRIS data, and the parameters of
algorithm were confirmed.
3.2
Algorithm development and data sets generation
OCTS algorithm has been improved gradually. The first version was used
from the beginning of operation to 9 April 1997, and then after 10 April,
version 2 was used to process the data. Version 3 will be available by the
end of September. The image quality is also improved by the same date.
So far, 10 CD-ROMs including OCTS and AVNIR data sets were made
by EORC as a sample data for users. After this, EORC is planning to
produce data sets such as match-up data set s of satellite data and truth data
dedicated to scientific users.
3.3
Results from ADEOS observations
Using data already acquired, sensor providers have processed and
distributed data such as the chlorophyll-a concentration in the ocean,