In its discussion concerning requirement analyses, the panel agreed that its earlier seven-category “GCOS missions” remained valid. It was clear that a comprehensive approach was needed to perform an analysis, but that the results must be presented in a comprehensible manner.
To address this issue, the Chairman presented an analysis concept. He illustrated an objective analysis methodology which he had recently developed for a WMO assessment of requirements and space resources, and then further refined for a more wide-ranging analysis required by CEOS (see Annex IV). The panel agreed that a similar analysis, thoroughly checked by an expert group, should be incorporated in the next edition of the Space Plan. This would be a comparison of the updated requirements, established with the help of the science panels, with the performance of the available space assets. Performance details should be obtained from the relevant space agencies, but carefully checked and approved by expert users before being incorporated in the analysis.
The panel noted that there is need to develop a more complete suite of requirements, in particular from GOOS and GTOS. Because of the current long lead time for planning activities in the space sector, this is an urgent matter. It was recommended that the planning committees of these programmes be informed of the need for them to provide additional information as soon as it can be prepared.
In order to develop a set of priority parameters to apply the analysis method, the Chairman proposed three ad hoc working groups be set up to identify a small number of critical variables. Participants divided into atmosphere, ocean and land working groups to identify ten or fewer 'core' parameters for each of the seven GCOS missions. Where possible, the working groups were asked to identify the most important parameters out of the ten 'core' variables. The resulting sublist should contain about three parameters. This preliminary identification of variables was to initiate the method, which will need to be verified by relevant science or application panels of the G3OS. The panel considered that this sublist should be treated in a different manner from the list of 'core' parameters and should not be transmitted formally as a requirement, but used internally by the panel to help focus specific recommendations. The 'core' parameters should be first-order variables capable of being observed from space and essential to meet user requirements. The ones finally selected would be published in the updated version of the Space Plan and would be used for CEOS analysis activities. A list of the specified parameters and the report of the working groups can be found in Annex V.
It was noted that as yet there are few quantitative requirements for atmospheric composition and the panel recommended that urgent attention is given to this gap.
The panel discussed how a review procedure can ensure the accuracy of the data requirements. The number of parameters should be sufficiently small, so that enough experts can be found for a review. The panel agreed to the following reviewing mechanism for the first 'cycle' of review: (1) the panel will prepare the first detailed list of parameters and will send the list to selected reviewers; (2) the list and associated comments relating to requirements and corresponding instruments will be used in the analysis process (Annex IV); and (3) the results sent back to the panel. For the second cycle, these decisions will be cross-checked and re-analysed by selected experts. Finally, the list will be returned to the panel.
