There are eight sensors on board ADEOS, provided by five agencies from three countries. The scientific objective of ADEOS is to contribute to the understanding of the global environment, especially global warming and stratospheric ozone depletion. Each sensor provider has its own science program for its sensor. The ADEOS science program is composed of these science programs. However, NASDA's ADEOS science program is larger than other programs of sensor providers because of its role as the platform provider. This paper describes the current status of NASDA's ADEOS science program.
NASDA established the ADEOS science program in order to ensure that the ADEOS data processing and analysis proves valuable for Earth system science. The major ADEOS science program activities are listed below.
Various algorithms have been developed in the ADEOS Science Program. The optimal algorithm is selected for NASDA based on the evaluation of these algorithms.
One of the most important tasks of the ADEOS science program is to offer data sets derived from ADEOS data to Earth scientists for global change studies. The planned value added datasets are listed in the table below. "96" indicates datasets that can be produced relatively soon after launch (about 6 months after launch); "99" indicates that necessary algorithms will be developed before the termination of the ADEOS mission, and the datasets can be produced (within 3 years after launch). This table shows the current plan and may change as the ADEOS Science Program progresses.
Application | Value Added dataset | Year | Sensors to be used |
---|---|---|---|
Carbon Cycle | Highly accurate land cover | 96* | AVNIR |
Global land cover | 99 | OCTS, AVNIR | |
Forest areas | 97 | OCTS, AVNIR | |
Vegetation index | 99 | OCTS, POLDER, AVNIR | |
Greenhouse gases | 99 | IMG | |
Chlorophyll | 96/99 | OCTS,TOMS, NSCAT,POLDER | |
Energy Cycle | Temperature/water vapor (upper troposphere) | 99 | IMG |
SST | 96/99 | OCTS/NSCAT, IMG | |
Ocean wind vector | 96 | NSCAT | |
Atmosphere-ocean interaction | 96 | OCTS, NSCAT IMG | |
Ocean circulation | 99 | OCTS, NSCAT | |
Ocean surface aerosol | 99 | OCTS, POLDER | |
Stratospheric ozone depletion | Total ozone | 96/99 | TOMS/IMG, |
Ozone profile | 96/99 | ILAS/IMG, TOMS | |
Elevation Sampling | Digital Elevation Modelling (DEM) | 96 | AVNIR |
Large-Scale Disasters | Volcanoes and volcanic products, SO2) | 96 | AVNIR, OCTS, |
Large scale wildfire | 96 | OCTS, AVNIR, IMG |
ADEOS carries eight sensors, including OCTS and AVNIR, with capabilities of higher precision measurements of ocean surface temperature, chlorophyll concentration and other atmospheric characteristics. Calibration and validation for OCTS and AVNIR are summarized below.
Buoy - An ocean observation buoy which NASDA has developed will be placed
in the Yamato-tai (Japan Sea) after ADEOS launch. It will serve as a fixed
observation point giving measurement of irradiance and radiance reflectance,
wind speed and direction, and ocean surface temperature. About 30 cloudless
datasets will be obtained in a year.
Ocean Data Acquisition Experiments in Cooperation with the Fishery Agency
- The ADEOS sensors are designed to obtain data on radiance, chlorophyll
concentration and ocean surface temperature, which are also measured by the
ocean observation buoy. About 200 cloudless datasets will be obtained in a year.
In order to assure the quality (accuracy) of these data sets, we must sufficiently calibrate sensors and validate data products. Although sensor providers are responsible for calibrating and validating their own sensor, NASDA, as both the platform provider and as a sensor provider for AVNIR and OCTS, will establish its CAL/VAL plan for ADEOS. The main components of this ADEOS CAL/VAL are field campaigns dedicated to multiple sensors on board ADEOS. Hence, cross calibration and validation are the focus of these ADEOS field campaigns. The draft plans of these ADEOS field campaigns are listed below.
Primary objective | Calibration and cross calibration of ADEOS sensors |
Test site | California, USA |
Time period | Feb. 1997 |
Primary objective | Validation of oceanic geophysical parameters |
Test site | Off shore of Sanriku, Northwest Pacific |
Time period | May 1997 |
Primary objective | Validation of atmospheric geophysical parameters |
Secondary objective | Snow and ice studies |
Test site | Fairbanks and Barrow, Alaska, USA |
Time period | April 1997 |
Primary objective | Validation of vegetation parameters |
Secondary objective (Test site 2) | Validation of ozone |
Test site 1 | Paso, Malaysia |
Time period | July 1997 |
Test site 2 | Yakutsk, Siberia, Russia |
Time period | Sep. 1998 |
Establishment of In-Situ Data Base
Field campaigns described above can provide valuable data for calibrating and validating ADEOS data processing and analyses. However, these data are essentially local data in time and space. We need much more in-situ data, not only for calibration and validation but also for data processing and analyses. In order to collect and manage these in-situ data for ADEOS science, NASDA is going to establish the ADEOS in-situ data base.
This ADEOS in-situ data base will be composed of many kinds of in-situ data, including data from field campaigns, data collected by ADEOS PIs, and data from existing data base such as meteorological data.
This data base will be established at the Earth Observation Research Center (EORC) which was established in April 1995 in Tokyo. Those data collected in the ADEOS in-situ data base, except some classified data, will be distributed to ADEOS PIs.
Management of Research Activities under Research Anouncement Program
NASDA has already issued two research announcements jointly with other sensor providers. The first research announcement was issued jointly with the Ministry of International Trade and Industry and the Japan Environmental Agency, and focused on general aspects of ADEOS science. Around 150 PIs have already been selected through this joint research announcement (JRA). Another JRA was issued with CNES, France, and focused on POLDER science.
We are going to issue a third JRA in 1995 focused on using ADEOS data in Southeast Asia and a fourth JRA focused on specific areas which the first JRA PIs do not cover.
Coodination of Scientific Mission Operation Requirement
Mission operation coordination is also important for the ADEOS science program. Although most ADEOS sensors are global sensors and will be operated continuously, some sensors have operations requirements. One typical sensor with operational requirements is AVNIR. AVNIR will be operated only on demand. Another problem of AVNIR is related to its pointing capability. Therefore, mission operation conflicts among the several requirements may occur.
Earth Observation Research Center