Remedy 1: Optimization of scheduling to enhance capability for satellite Cal/Val activities

Sustained funding and governance mechanisms need to be instigated and assured that optimise the observational scheduling of relevant high-quality non-satellite periodic (non-continuous) measurements and their provision in NRT for satellite characterisation, if the full potential value of these measures is to be realised. To be effective, space agencies and non-satellite high-quality observing networks need to work together to design, instigate, and fund a sustained program of targeted measurements that optimise collection and dissemination of non-satellite data in support of the space-based observational segment. The scientific benefits will be maximised if a strategy can be devised, which optimizes the ability of the non-satellite data segment to characterize satellite instrument performance across time, across platforms and across instrument types. This, in turn, points to individual non-satellite observational segments being tasked with helping to characterise across multiple missions from multiple agencies from multiple countries to maximise the scientific value of the cal/val exercise rather than this support being extended and decided on a per mission basis. The strategy should include recourse to other measurements. For example, EUMETSAT have recently introduced a forecasting tool, which can, with high probability, forecast colocations of radio-occultation measurements with a ground-based instrument and any given polar orbiter mission. Finding such occurrences potentially enhances the value of co-locations substantially by making them multi-point comparisons.

Care must be taken for any changes in scheduling not to impact deleteriously upon existing functions and purposes of the non-satellite segment. This implies that, in at least some cases, the remedy will need to involve funding support commensurate with taking new or additional measurements at sites. The most obvious solution would be to instigate an international measurements support program, which would administer and disperse funding support for sustained satellite cal/val with reference-quality data from operators who optimise spending decisions and have as active stakeholders space agencies, non-satellite data providers, and end-users.