GMS Pathfinder Project

The GMS Pathfinder Project was a collaborative project between the Commonwealth Bureau of Meteorology (CBoM), the Commonwealth Scientific & Industrial Research Organisation (CSIRO), the US National Aeronautics and Space Administration (NASA) and Scripps Institution of Oceanography (SIO) at the University of California San Diego.

GMS was Japan's Geostationary Metrological Satellite (or "Himawari") series operationally stationed since 1978 at an altitude of 36 000 km above the equator at a longitude 140 degrees East. The last satellite in the series, GMS-5, used the Visible and Infrared Spin Scan Radiometer (VISSR) as its imaging instrument which operated in 4 channels: visible 0.4-1.1 microns, infrared: 6.5-7.0, 10.5-11.5 and 11.5-12.5 microns. On 22 May 2003, GMS-5 was temporarily backed-up by GOES-9, which will be replaced by MTSAT-1R in 2004.

The GMS Pathfinder Project aimed to demonstrate the usefulness of longer time series satellite data and products for scientific research, in particular the study of climate.

Objectives

• to develop a noise corrected, radiometrically calibrated, properly cloud-screened accurate GMS-5 (S-VISSR) benchmark data set;
• to demonstrate the scientific importance of improved GMS-5 data by producing a VISSR-based set of products (eg: browse or quick look images and metadata; albedo; cloud cover variability; sea surface temperatures; and net solar radiation) and scientific studies useful to global climate change community; and
• to prescribe and improve archive and distribution procedures for using GMS data.

Method

The GMS Pathfinder Benchmark period (1 July 1995 - 30 June 1996) was chosen to demonstrate proof of concept. For this period, the project was to produce a high-quality time series of improved products for use by the global change research community covering the Australian continent and adjacent ocean areas (5^o to 50^oS lat. and 110^o to 150^oE long). Specific tasks included:

(a) Re-archive the CBoM GMS data for the GMS Pathfinder Benchmark Period onto new media, and generate browse and metadata to enable enhanced access by the scientific user community. This is an ongoing cooperative effort between ABM and SIO.

(b) Examine the GMS data for sources of noise which would inhibit their quantitative use in global change studies. Develop, where applicable, noise reduction algorithms analogous to the procedures developed for the GOES S-VISSR data.

(c) Develop rigorous, fully-automated cloud-detection algorithms for GMS data for use over both land and ocean. These products are needed for many other scientific studies.

(d) Radiometrically calibrate the GMS S-VISSR data using both calibration sites and a combination of GMS and AVHRR scenes.

(e) Improve the navigational accuracy of the GMS-5 data.

(f) Provide a demonstration of the scientific usefulness of GMS Pathfinder within the context of large-scale regional studies.

Results

• A demonstration of improvement in visible image destriping using a specially developed set of tapered finite impulse response filters;
• Visible channel calibration of GMS-4 and GMS-5 using cross-calibration with the AVHRR instrument of NOAA-14;
• A new method to generate cloud cleared scenes;
• An extensive cross-calibration between the thermal channels (11 and 12 microns) on GMS-5 and ATSR-2 (Along Track Scanning Radiometer).

A complete copy of the data (~800Gb) is held by the CBoM, CSIRO (EOC) and the Scripps Institution of Oceanography (UCSD). To obtain data from the project or for more information contact the Space Based Observations Section.

Links

References

Frouin,R.J. and Simpson,J.J., 1995, "Radiometric calibration of GOES-7 VISSR solar channels during the GOES Pathfinder benchmark period", Remote Sensing of the Environment, Vol.52, pp.95-115.

Le Marshall,J.F., Simpson,J.J., Jin,Z., 1999, "Satellite Calibration Using a Collocated Nadir Observation Technique: Theoretical Basis and Application to the GMS-5 Pathfinder Benchmark Period", IEEE Transactions on Geoscience and Remote Sensing, Vol.37, No.1, pp.499-507.

Merchant,C.J., Simpson,J.J., Harris,A.R., 2001, "A Cross-Calibration of GMS-5 Thermal Channels Against ATSR-2". (To be submitted)

Simpson,J.J., Le Marshal,J.F., Kingwell,J., Neal, A.B., Griersmith,D.C., 1998, "The GMS Pathfinder Project", Australian Met.Mag., Vol.47, pp.225- 236.

Simpson,J.J., Stitt,J.R., Leath,D.M., 1998, "Improved finite impulse response filters for emhanced setriping of geostationary satellite data", Remote Sensing of the Environment, Vol.66, pp.235-249.