Summary of EOS Direct Broadcast Meeting

Canberra, Australia, December 1998

Ian Barton (ian.barton@marine.csiro.au), CSIRO Marine Research, Hobart, Australia
Jim Dodge(jdodge@hq.nasa.gov) NASA Headquarters

Following on from previous successful meetings on the direct broadcast (DB) of data from EOS platforms to national and foreign ground stations, a meeting jointly arranged by Australia and NASA was held at CSIRO Headquarters in Canberra, Australia during December 1998. The Australian organising committee was formed by members of the Tasmanian Earth Resources Satellite Station (TERSS) which operates an X-Band station in Hobart, Tasmania.

The delegates were welcomed by Dr David Jupp, Head of CSIRO's Office of Space Science and Applications (COSSA). David commented on the timeliness of the meeting and the value of real-time data in many different applications, especially for countries with large, sparsely-populated areas and/or large extended marine Extended Economic Zones.

The meeting kicked-off with a presentation from Jim Dodge who provided information on the status of NASA's EOS Program including plans for the direct broadcast of data to ground reception stations. For the AM-1 platform only data from the MODIS instrument would be available, but for the PM-1 satellite earth observation data from all instruments would be available via direct broadcast. Currently NASA is planning for four national reception sites ­ Hawaii, University of South Florida, University of Wisconsin, and GSFC. Software packages to assist in the preliminary analysis of the DB data are under development at GSFC and Wisconsin. Many foreign stations, including those in Europe, Asia, South America, and Australia, are also planning direct reception of these data. The importance and value of blending EOS data with those from other sources (including other satellites) was stressed. Finally Jim stated that NASA is committed to the concept of an international user community which shares information on data reception, processing algorithms, calibration and validation. Also, NASA's policy is to support free exchange of EOS data for approved scientific, operational public good uses and educational users.

The introductory talk was followed by five speakers, each giving examples of the importance of real-time data in different applications. Richard Smith of the Western Australian Department of Land Administration (DOLA) gave examples of the use of AVHRR data in the management of agricultural areas with special emphasis on the detection of areas affected by salinity and by grass fires. DOLA currently operate an automated near real time fire monitoring program for northern Australia based on NOAA AVHRR data. Richard also stated that a consortium in Western Australia was planning to develop Australia's third X-band reception station in Perth over the next year. This would ensure that a range of new data, including possibly real-time EOS DB data could be made available to applications in Western Australian.

Rob Lees of SPOT Services Australia described the new VEGETATION instrument on the French SPOT-4 satellite. Data are transmitted to European ground stations on both X-band (global data) and S-band (local data). Global data processing is undertaken in Belgium while S-band station are able to process their data in near real-time. Data products include ten-day composites of vegetation indices with cloudy areas removed. The data products were finding wide applications in the management of agriculture, land use, and environmental studies.

Ian Barton of CSIRO Marine Research described the many benefits of the use of real-time satellite data in the management and research of Australia's Marine Exclusive Economic Zone ­ an area that is larger than the Australian land mass. Currently data from many different satellites are used and these will be augmented by those from the EOS program in the coming years. Australia also maintains a comprehensive network of satellite data validation sites, both on the land and over the oceans. These data will be made available to satellite operators to assist in the continuing monitoring of instrument performance. Barton also stressed the need for the development of a suitable processing package which would allow foreign direct broadcast reception stations to obtain Level 1B data products (geo-located geophysical quantities) from the raw DB data stream.

Graham Harris of CSIRO Land and Water gave the fourth presentation in this group, and talked about a new program to address and reverse salinity and erosion problems in one of Australia's main agricultural areas ­ the Murray-Darling Basin. Over the past years poor land management, deforestation, and over-grazing has led to a large increase in non-productive land. A major program of reforestation was planned to address these issues and accurate and timely remote sensing techniques for monitoring the reclamation process were essential. Discussions are being held between CSIRO and NASA on the potential for this major undertaking to be an international focus of earth observing activities.

The last presentation was from Jim Simpson of Scripps Institution of Oceanography, UCSD. Jim described plans to collect satellite data for an area of 1000 km by 1000 km centred on Hawaii. By collecting data from all available satellite instruments (EOS, AVHRR, SeaWiFS, etc.) as well as ground-based data, the experiment would show the value of combining these data in the derivation of geophysical parameters. Improved techniques for cloud clearing over the oceans and the determination of cloud heights over land were described. Using MODIS data it should be possible to derive cloud heights with an accuracy of 200m. Finally Jim commented that the extra channels of data available with MODIS should lead to an improved detection of volcanic ash clouds for increased aviation safety. The DB of MODIS data to foreign stations would be essential if the aviation industry was to benefit from this application in the time-frame it needs.

Peter Bayliss of the University of Dundee, Scotland delivered the first of four talks on the development of X-band stations for the reception of DB from environmental satellites. The University of Dundee has been receiving AVHRR data for many years and is now planning to install an X-band station. They have obtained a 3.7 m antenna and have developed a novel moveable feed to overcome the key-hole problem. The university has also developed a signal simulator for testing the new system.

Bertil Gransberg of the University of Karlstad, Sweden described the development of a similar system for the DB reception of data from the AM-1 and PM platforms. He also has a 3.7 m Cassegrain antenna and gave detailed information on the complete system. Data applications will include vegetation, snow, and ice monitoring as well as weather forecasting.

The third presentation was jointly delivered by John Woolner and Andrew Longhorn of the Australian Centre for Remote Sensing (ACRES). John described the two Australian X-band receiving stations at Alice Springs and Hobart. These stations are both managed by ACRES with the former being operational for almost twenty years. Both stations are currently undergoing a full upgrade and Andrew presented details of the improvements. The upgrades will provide full automatic operation, with on-line browse products being available within one hour of reception. ACRES were also investigating the distribution of selected, small-area products over the internet in near real-time. Both Australian stations are potentially available to receive DB data from the EOS satellites for specific real time applications and ACRES is very interested ton progress the development of these applications.

Torben Neilsen of the University of Hawaii described the Hawaii satellite reception system which is based on a 5 m antenna. The design philosophy is to concentrate on using software whenever possible. Currently the system is capable of receiving data from Landsat-5 and ERS-2, and is ready to receive data from the Landsat-7, AM-1, and PM-1 satellites when they are launched. The full system was developed "in-house", and basic design details are available. Torben also stressed the need for a good orbit model for a system that does not have an auto-track facility.

The use of data from the EOS program in weather forecasting was the topic of a further three presentations. For the weather services the most useful satellite data products are from the sounding channels of satellite instruments which give vertical profiles of temperature and water vapor over remote areas. MODIS on both EOS platforms would be able to provide this information with an improved horizontal spatial resolution, while the AIRS instrument on the PM-1 platform would give an improved vertical resolution though the provision of high spectral resolution data at the appropriate wavelengths. John Le Marshall of the Australian Bureau of Meteorology described these two instruments as the "new generation" for weather forecasting. The world's weather services are eagerly awaiting these data ­ but to ensure that the real-time products are fully exploited will require the reception of DB data and the provision of an analysis package to quickly and easily interpret the data. In the past much has been gained from an early release of appropriate software, and John suggested that this would also be true for the EOS era. Finally John gave some impressive examples showing the value of real-time cloud-drift winds in the successful forecasting of the tracks of tropical cyclones (hurricanes).

Paul Hwang and Gene Shaffer of GSFC, NASA described the development of a Level 1b software package for the interpretation of data from the instruments on the PM-1 satellite including the AIRS. They also presented details of the status and schedule of PM-1. NASA have plans for an internet site for potential users of data from the satellite which would also address DB issues.

Bjorn Lambrigtsen of JPL, NASA gave a full description of the AIRS instrument including the development of a full processing system. He stated that JPL will support DB activities as far as funding and time would permit. A preliminary release of software is expected by mid-1999. The AIRS Science Team is also working closely with the International TOVS Working Group (ITWG). This group of representatives from international weather services has been extremely successful in the exploitation of data from the vertical sounding instruments on the NOAA operational meteorological satellites.

The one remaining presentation was from Liam Gumley of the University of Wisconsin-Madison. He described the development of one of NASA's EOS ground stations and the parallel development of a processing package which would provide Level 1b products from the EOS DB data stream. Both activities are receiving funding support from NASA. The processing package would eventually be widely available to ground stations capable of receiving the DB data stream. Wisconsin are hoping to involve the international community in the development and evaluation in this project. The main goal of the Wisconsin group is to exploit MODIS data to provide improved satellite data products for clouds and the atmosphere.

Prior to the final discussion session Fritz Hasler (NASA GSFC) and his colleagues gave an animated 3-D presentation of earth observation data. A sequence of geostationary satellite data at 1 minute intervals gave an impressive visualisation of a tropical hurricane. The demonstration included close-up and cross sectional views of the eye of the hurricane as well as including over-laid wind vectors. Several other examples demonstrated the power of these techniques for interpretation, research and educational applications.

In the closing session Ian Barton provided a summary of the meeting and also suggested several points for further discussion. Following the summary there was wide ranging debate about IP issues relating to processing software and the distribution of data products. Jim Dodge reconfirmed that NASA operate under a policy of free exchange of data for approved research, operational public good activities and educational applications. However, use of DB data for commercial outcomes would need to be negotiated with NASA. Generally also, DB applications would real time with data for less time critical applications being obtained from EOSDIS. During the meeting it became evident that there is now a depth of international knowledge to assist in the development of international networks of national X-band reception stations. This is well complemented by a set of documents, available from NASA, to assist with the development of effective reception facilities for DB data from NASA's EOS satellites. The meeting noted the absence of delegates from ESA, Japan, and some other countries (due to a number of reasons) and a wider international attendance at the next meeting would be encouraged.

There were three technical tours associated with the meeting. Two of these were completed during the meeting in Canberra ­ the first to the ACRES facility where delegates experienced, at first hand, the production of satellite data products from data received at the Australian X-bands stations. The second tour was to NASA's Deep Space Tracking Station at Tidbinbilla near Canberra. This is one of three global stations used for NASA's interplanetary missions. The third technical tour to Hobart followed the meeting. This tour included visits to the Hobart X-band station, the CSIRO Marine Laboratories, the University of Tasmania, and the Australian Antarctic Division.

A more complete report of the meeting is available at http://www.eoc.csiro.au/ under the heading "Direct Broadcast Meeting Reports".