Figure 1. Example of topics relating to ERS-2 that are provided online, on Internet (under the address 'http://services.esrin.esa.it')
Real-time provision of news and documentation relating to ERS-2 via Internet - that is a new service that ESRIN, ESA's centre in Italy, is now offering. The special ERS-2 service gives new momentum to the utilisation of the World Wide Web and file-transfer utilities that have been maintained by ESRIN for over a year now to provide attractive, online information retrieval and publishing services to the Earth-observation community around the world.
Keeping the world informed about a satellite's life from the time of its birth may seem like an odd endeavour. As soon as people realise, however, that the satellite ERS-2 can provide unique and vital data in many areas like ocean navigation, ice or crop monitoring, and oil or gold exploration, interest grows: it becomes of utmost importance to know whether the satellite system is completely functional and whether the mission is proceeding as planned. That information is now offered on the Internet as a Special ERS-2 Service and can be accessed under the World Wide Web (Fig. 1).
The special ERS-2 service has allowed those interested to first learn about many aspects of the satellite and its launch, and then to keep up-to-date as it progresses through its commissioning phase. Even before the ERS-2 launch, the special ERS-2 service provided online the full text and graphics of the most recent publications, with special emphasis on the commissioning phase and the tandem operation of the satellite with ERS-1. Immediately after launch, news on the first orbital manoeuvres was added. The very first sensor switch-on reports, describing which sets of sensors were already functioning, also appeared online.
The instrument's coverage of the Earth was shown in graphical illustration as it occurred - in the morning, only a thread ran over the map of the Earth and by the evening, long strokes of paint covered it. Day after day, as the number of completed orbits grew, the map of the Earth disappeared gradually behind lines indicating the completed orbits. In addition, vital parameters for the calibration and validation of the on-board instruments were registered and published (Fig. 2); they remain searchable for the duration of the satellite's life.
After the first exciting months of ERS-2, all will become 'routine', as it has for ERS-1. The online service will allow people to stay current on the satellite, the payload, the ground segment, the research and data applications, and thus will be essential for those using ERS-2 data and ordering ERS-2 products (see boxes).
Figure 1. Example of topics relating to ERS-2 that are provided online, on Internet (under the address 'http://services.esrin.esa.it')
Figure 2. Example of an ERS-2 data display as shown online
In parallel to the updating of the online information, which takes place sometimes several times a day, ESRIN has been monitoring the usage of the new service. At first, many people connected to glance at what ERS-2 was, stopping at the high-level screens; since then, they have started to open the more detailed screens, with articles for instance on the new ozone sensor, GOME. The rapid provision of information online has also played a promotional role for ERS-2: the first images were readily available online to the press around the world.
More surprising though is the interest in the online service shown by the professionals involved in ERS-2, be they the satellite builders, the sensor builders or those responsible for the instrument calibration. The Earth Observation community and in particular scientists who conceived the technology behind the sensors have connected to the service from all over the world. French, British, German and Dutch research centres ranked first among the most frequent users.
Finally, ESA managers have proven to be the greatest aficionados of the online service with special ERS-2 news. They have found a tool that is at their fingertips and allows them to both control the information released and show or discuss the new satellite's performance with others around the world.
An awareness tool, a communication tool and a reference information base - those are the functions that the new service is offering to the user community.
Finding the right mix between technology, data quality and timeliness, man-machine interface and user friendliness has been necessary to attract the user community's interest in the service.
Data quality has been secured through tight coordination among the ESA scientists themselves, wherever they are located, with the ESA mission operators and with ESA management. The information released has been designed to satisfy both the specialist and the layman. Great effort has also been expended to ensure user friendliness. On one hand, the cosmetics relative to screen layout and the use of images have been given special care. On the other hand, preceding the technology performance and the aesthetical work, all the information to be included - several hundreds of items - has been given a solid architecture. Each data object has been given its place, and each future piece has already been assigned a location within the huge information tree.
That hidden work has allowed for the creation of an effective network of cross-references. Any information can thus be reached via several paths, all echoing each other without the user feeling lost. The manager can go to the news, the specialist can point to 'his' sensor, the teacher can go to 'his' volcano, the frequent searcher can search by date: in the end, they will all find the same piece of information, the same picture or the same graphic.
Moreover, user reaction to the service will be evaluated at regular intervals and adaptations made accordingly. By carefully monitoring the most successful online items, further possible cross-references among the screens offered can be made thus tightening the hypertext links in a user-driven evolutionary process.
To complete the picture, official reference documents have been placed online in abstracted form or in full text. Those who want to obtain a printed copy of one of the documents can also order it from ESRIN without bothering about downloading times. Lastly, users can leave a message or call the ERS Helpdesk for advice on how to take advantage of all the service features (see the earlier box for information on how to contact the Helpdesk).
The special ERS-2 information is carried by and fully integrated with a number of information services that ESRIN introduced in 1994.
Under the overall heading of 'User Earth Remote Sensing Services', or 'usERServices' for short, ESRIN provides a number of inter-linked multi-mission services to users. Besides the special ERS-2 feature, current headlines include:
They are all targeted at satisfying different needs for instantaneous online access to information on the ESA remote-sensing programmes and satellite missions.
The ESA Earth Observation 'Guide and Directory Service' (GDS) represented the start of ESRIN's presence on Internet. For more than a year now, it has been providing the user community with Earth- observation back-ground information (some 40 000 documents) relevant to ESA missions (ERS and Meteosat) and those missions whose data ESA acquires and disseminates (see ESA Bulletin, No. 78, May 1994).
The GDS carries the following information:
Under the impetus of events within both ESA and the user community, GDS has taken on additional tasks but a number of information items have also been transferred to specially focused service headlines, an example being 'Hot News and Hot Online' which is now provided separately.
GDS's ability to publish online, in a very short time, has made it a forum for user groups with special interests. Two institutions, CEOS (the Committee on Earth Observation Satellites) and EARSeL (the European Association of Remote Sensing Laboratories), maintain information collections in GDS, and thus are accessible either under their own addresses, or from within the services offered by ESRIN (Fig. 3).
Figure 3. ESA also hosts information services for a number of institutions involved in Earth observation. They can be
accessed directly from the WWW under the addresses shown or via the GDS Home Page
Since the first ESRIN Earth-observation service was officially opened to the World Wide Web in May 1994, user interest has increased rapidly, as the usage statistics in Figure 4 illustrate. At the time of the initial service announcement, some 12 000 requests for information were received per month, whereas a year later, and with ESRIN providing a richer set of services, the number has grown to over 69 000, an increase by a factor of almost 6. Figure 4 also shows a marked peak which corresponds to the introduction of the ERS-2 service.
The geographic location of users is quite diverse. As shown in Figure 5, Western Europeans and North Americans are the primary users of the services, but small but consistent groups of users also exist in Australia, Japan, Eastern Europe, and Southeast Asia.
Figure 4. Usage of ESA's online Earth-observation services on World Wide Web (accesses between 1 May 1994 and 31 May 1995)
Figure 5. User access by region of the world (between 1 May 1994 and 31 May 1994). The total number of accesses was 338,799
ESRIN's present information services, however, are not expected to remain static. Since the information base is growing and a presence on the networks must reflect evolving user needs, the evolution of the services and the creation of optimised multi-mission information access paths will remain an ongoing activity. The immediate significant user response to the introduction of new and efficient features proves that 'information highways' like Internet allow for instantaneous user community response, in the Earth-observation domain as well.
User support and help:
ERS Helpdesk
ESA/ESRIN
Via Galileo Galilei
I-00044
Frascati Italy
Phone:(+39) 6 94180 600
Fax: (+39) 6 94180 510
E-mail:
helpdesk@ersus.esrinvas.esrin.esa.it
ESA Bulletin Nr. 83.