Satoshi Tsuchida

Applicability of Green-Red Vegetation Index for Remote Sensing of Vegetation Phenology

We evaluated the use of the Green-Red Vegetation Index (GRVI) as a phenological indicator based on multiyear stand-level observations of spectral reflectance and phenology at several representative ecosystems in Japan. The results showed the relationships between GRVI values and the seasonal change of vegetation and ground surface with high temporal resolution. We found that GRVI has the following advantages as a phenological indicator: (1) “GRVI = 0” can be a site-independent single threshold fordetection of the early phase of leaf green-up and the middle phase of autumn coloring, and (2) GRVI can show a distinct response to subtle disturbance and the difference of ecosystem types.

Vicarious Calibration of ASTER via the Reflectance-Based Approach

The reflectance-based vicarious calibration approach has been applied to the Advanced spaceborne Thermal emission and reflection radiometer (ASTER) that is on the Terra platform. The results from three separate groups operating at the same sites at the same time are presented. The three groups show good agreement between each other, with differences between the groups being smaller than 4% in all bands ranging from 0.6 to 2.2 mum and with larger differences being seen at shorter wavelengths and beyond 2.2 mum. comparisons between the groups and to the ASTER sensor are best at 1.66 mum (band 4), with differences between each group being less than 0.5% and all of the groups agreeing with ASTER to better than 5%. Differences in the visible and near infrared (VNIR) are larger, particularly prior to August 2002 when an update to the calibration processing was performed. These differences exceed 10% in some bands. In addition, the vicarious results appear to show a different trend than the onboard calibration for the VNIR indicating a possible problem with the onboard calibrator for bands 1-3.

ASTER preflight and inflight calibration and the validation of Level 2 products

Describes the preflight and inflight calibration approaches used for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The system is a multispectral, high-spatial resolution sensor on the Earth Observing Systems EOS-AM1 platform. Preflight calibration of ASTER uses well-characterized sources to provide calibration and preflight round-robin exercises to understand biases between the calibration sources of ASTER and other EOS sensors. These round-robins rely on well-characterized, ultra-stable radiometers. An experiment field in Yokohama, Japan, showed that the output from the source used for the visible and near-infrared (VNIR) subsystem of ASTER may be underestimated by 1.5%, but this is still within the 4% specification for the absolute, radiometric calibration of these bands. Inflight calibration will rely on vicarious techniques and onboard blackbodies and lamps. Vicarious techniques include ground-reference methods using desert and water sites. A recent joint field campaign gives confidence that these methods currently provide absolute calibration to better than 5%, and indications are that uncertainties less than the required 4% should be achievable at launch. The EOS-AM1 platform will also provide a spacecraft maneuver that will allow ASTER to see the Moon, allowing further characterization of the sensor. A method for combining the results of these independent calibration results is presented. The paper also describes the plans for validating the Level 2 data products from ASTER. These plans rely heavily upon field campaigns using methods similar to those used for the ground-reference, vicarious calibration methods.

Evaluation of optical satellite remote sensing for rice paddy phenology in monsoon Asia using a continuous in situ dataset

In monsoon Asia, optical satellite remote sensing for rice paddy phenology suffers from atmospheric contaminations mainly due to frequent cloud cover. We evaluated the quality of satellite remote sensing of paddy phenology: (1) through continuous in situ observations of a paddy field in Japan for 1.5 years, we investigated phenological signals in the reflectance spectrum of the paddy field; (2) we tested daily satellite data taken by Terra/Aqua MODIS (MOD09 and L1B products) with regard to the agreement with the in situ data and the influence of cloud contamination. As a result, the in situ spectral characteristics evidently indicated some phenological changes in the rice paddy field, such as irrigation start, padding, heading, harvest and ploughing. The Enhanced Vegetation Index (EVI) was the best vegetation index in terms of agreement with the in situ data. More than 65% of MODIS observations were contaminated with clouds in this region. However, the combined use of Terra and Aqua decreased the rate of cloud contamination of the daily data to 43%. In conclusion, the most robust dataset for monitoring rice paddy phenology in monsoon Asia would be daily EVI derived from a combination of Terra/MODIS and Aqua/MODIS.

Detection of a landslide movement as geometric misregistration in image matching of SPOT HRV data of two different dates

A landslide movement was detected as geometric misregistration in image matching between two SPOT HRV panchromatic image data of different acquisition dates. The test site is an active landslide in Itaya area, Yamagata Prefecture, northern Japan. The average rate of the landslide movement is approximately 1 cm per day based upon differential GPS measurements. Pixel level and subpixel level image matching was applied to an HRV image pair obtained on 1 November 1987 and 29 October 1993. As a result, the landslide movement was successfully detected as misregistration vectors between the two HRV scenes. The displacement is approximately 20 m to 30 m over the 6-year period between 1987 and 1993 and is consistent with the landslide movement inferred from the GPS measurements.

Design Principles and IT Overviews of the GEO Grid

As the Earths ecosystem is a spatially and temporally complex system by nature, it is not sufficient to observe such events and phenomena locally; problems must be solved on a global scale. Therefore, the accumulation of knowledge about the Earth in various forms and a scientifically correct understanding of the Earth are necessary. The authors have been leading the ldquoGlobal Earth Observation (GEO) Gridrdquo project since 2005, which is primarily aimed at providing an e-Science infrastructure for the worldwide Earth sciences community. In the community, there are wide varieties of existing datasets including satellite imagery, geological data, and ground sensed data that each data owner insists own licensing policy. Also, there are so many related projects that will be configured as a virtual organization (VO) enabled by Grid technology. The GEO Grid is designed to integrate all of the relevant data virtually, again enabled by Grid technology, and is accessible as a set of services. In this paper, first we describe design principles of the GEO Grid that are determined based on accommodating users requirements for publishing, managing, and using data. Second, software architecture and its preliminary implementations are specified where we take the Grid computing and Web service technologies as the core components that comply with a standard set of technologies and protocols. In addition, GEO Grid has been recognized to contribute to GEO or Global Earth Observation System of Systems (GEOSS) as a part of the Japanese governments commitment.

Onboard calibration of the ASTER instrument

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution optical sensor for observing the Earth carried on the National Aeronautics and Space Administration Terra satellite. ASTER consists of three radiometers covering the following regions: visible and near-infrared (VNIR), shortwave infrared (SWIR), and thermal infrared (TIR). The preflight calibration of VNIR and SWIR utilized standard large integrating spheres whose radiance levels were traceable to primary standard fixed-point blackbodies. The onboard calibration devices for the VNIR and SWIR consist of two halogen lamps with photodiode monitors. In orbit, all three bands of the VNIR showed rapid decreases in the output signal while all SWIR bands remained stable. The TIR onboard blackbody was calibrated against a standard blackbody from 100-400 K in a vacuum chamber before launch. The TIR is unable to see the dark space. The temperature of the TIR onboard blackbody remains at 270 K for a short-term calibration to determine any offset and is varied from 270-340 K for a long-term calibration of both the offset and gain. The long-term calibration just after launch was consistent with the prelaunch calibration but then showed a steady decrease of the TIR response over the five years of operation to date.

GEO Grid: Grid Infrastructure for Integration of Huge Satellite Imagery and Geoscience Data Setsets

We have designed Global Earth Observation(GEO) Grid, which is an infrastructure for archiving and processing huge satellite imagery and GIS geographical data sets. Users can immediately access the full archive and process the desired data areas on demand using the latest calibration and analysis algorithms through standardized web services interfaces on basic OGSA services. GEO Grid is based on four layers, hardware, virtual storage, application and data services, and user interface. Each layer has the potential for extendability. We constructed GEO Grid to process satellite data taken by ASTER launched at the end of 1999 as an EOS project.

Current status of Hyperspectral Imager Suite (HISUI)

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral and multispectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI project is currently being promoted by three organizations each of which has a contract with METI together with several scientists from universities and national research institutes. The current status of HISUI project will be introduced in the presentation.

Creation of New Global Land Cover Map with Map Integration

We present here a new approach to the development of a global land cover map. We combined three existing global land cover maps (MOD12, GLC2000, and UMD) based on the principle that the majority view prevails and validated the resulting map by using information collected as part of the Degree Confluence Project (DCP). We used field survey information gathered by DCP volunteers from 4211 worldwide locations to validate the new land cover map, as well as the three existing land cover maps that were combined to create it. Agreement between the DCP-derived information and the land cover maps was 61.3% for our new land cover map, 60.3% for MOD12, 58.9% for GLC2000, and 55.2% for UMD. Although some of the improvements we achieved were not statistically significant, this project has shown that an improved land cover map can be developed and well-validated globally using our method.