Figure 1. The ESA entry, based on the five-level structure defined for space agencies
One of the most visible outputs of CEOS activities in the last years has been the production and publication of the so-called 'CEOS Dossiers'. Produced on paper and distributed to all CEOS members, the aim has been to set out CEOS's current and future plans and their relevance to user needs (particularly those of the CEOS Affiliate representing the users).
The task of updating the Dossier Volume A (Satellites, Missions) and Volume B (Affiliate Requirements), both dated September 1994, has been considered a high-priority activity. This was a prerequisite in enabling the CEOS Plenary Task Force on Planning and Analysis, chaired by Bizzarro Bizzarri, to analyse whether available instruments can meet the requirements of the user community well into the next decade.
ESA initiated the CEOS Dossier Project in 1996 to implement a database on user requirements and space capabilities that would allow the Task Force members to share and update information on- line.
The implementation of the CEOS Dossiers on-line database falls under the responsibility of the team handling the CEOS InfoSys at ESRIN. The initial objectives have been to:
In particular, it has been important to provide an overall system to the Task Force in order to share the maintenance of the on-line information and to facilitate the authorisation of its validity prior to its publication.
Based on the ORACLE Database Management System, the CEOS Dossier is a World Wide Web interface with an access-control mechanism. Each member has a user name and password that allows:
The completeness of information is based on a five-level structure introduced and agreed upon by the Task Force and maintained by each CEOS space agency (Figure 1):
Figure 1. The ESA entry, based on the five-level structure
defined for space agencies
The Affiliate programmes' user requirements are organised in terms of parameters as a function of applications. At present about 50 applications are stored covering the Affiliates: WMO, WCRP, GCOS, IOC, IGBP, ICSU, UNFP, UNOOSA, and the European Commission programmes, using over 90 geophysical parameters (e.g. temperature profile, sea-surface temperature). Requirements and instrument performances for each of these parameters are expressed in terms of horizontal and vertical resolution, accuracy, observing cycle, delay in availability, and confidence level.
The CEOS Dossier has several powerful features. It not only allows updates to be made on-line, but also permits basic analyses of application requirements. This is facilitated by the introduction of a graphical package directly interfaced to the database, which displays two-and three-dimensional plots (Figure 2). The user may choose to plot from a list of geophysical parameters, for any combination of horizontal and vertical resolution, accuracy, observing cycle, and delay availability.
Figure 2. An example of a two-dimensional plot of Temperature
Profile: horizontal and vertical resolution versus accuracy
The CEOS Dossier development was completed in November 1996 and was demonstrated at the CEOS 10th Plenary Session, on 13 15 November 1996, in Canberra, Australia. During 1997, the system will go on-line to allow all CEOS Members and Affiliates to update and validate the information that it carries. It is intended to produce a limited paper copy of the Dossier and to make the electronic browser publicly available for the entire Earth-observation community to consult. It is also intended to integrate the information in the Dossier with other Earth-observation information systems - notably CEOS Infosys and CEOS IDN - to increase the added value of the service.
ESA Bulletin Nr. 89.