Assessment of Mesoscale Features using Altimeter Constellations
Cutter, Mike1; Graham, Kathryn2; Regan, Amanda3; Cotton, David4; Shaw, Andy5; Challenor, Peter6; Martin, Matthew7; Le Roy, Yves8; Berry,, Phillipa9; Smith, Richard9; Smith, Richard9
1Surrey Satellite Technology Ltd, UNITED KINGDOM; 2SSTL, UNITED KINGDOM; 3ESA, NETHERLANDS; 4SatOC, UNITED KINGDOM; 5NOC, Southampton, UNITED KINGDOM; 6Exeter University, UNITED KINGDOM; 7Met Office, UNITED KINGDOM; 8Thales Alenia Space, FRANCE; 9De Montfort University, UNITED KINGDOM

It is recognized that the kinetic energy of the mesoscale variability in the ocean interior is much stronger than the kinetic energy of the large-scale mean circulation. Consequently, there is a keen interest in monitoring these features in a timely manner and with adequate spatial sampling. One possible route is via the use of a constellation of small satellites carrying altimeters. However, to facilitate the feasibility of such an approach, particularly with respect to overall cost, it is advisable to consider reducing the payload complement and utilising ionospheric and tropospheric models. The fundamental question is: ''would such an approach deliver adequate information to delineate the mesoscale features and what would be the optimum configuration of the constellation?''.

In principle this innovative approach of using a small-satellite altimeter constellation has the potential to offer timely coverage of the oceans and possibly the coastal zones and in-land water. Furthermore, the type of altimeter constellations being proposed could provide added benefit to the existing missions and enable higher measurement density together with improved robustness to degradation and platform and payload failures.

SSTL is currently leading a European team comprising oceanographers, modellers and algorithm developers to undertake an ESA study into the scientific assessment of fine scale altimetry using a constellation of small satellites. The SSTL consortium includes, the National Oceanographic Centre in Southampton (UK), The UK Met Office, Satellite Oceanographic Consultants (UK), de Montfort University (UK) and Thales Alenia Space (F).

The aim of this activity is to parametrically establish the link between altimetry satellite constellation characteristics and the final end-to-end performance levels needed to derive ocean circulation patterns, coastal phenomena and in-land water levels. The first part of the study involved a survey of user needs and the subsequent development of an assessment model, which has been driven by realistic oceanographic data sets and this has facilitated detailed end-to-end analysis. The emphasis of the work has been to determine the ability of different satellite constellation configurations to measure mesoscale ocean features against an agreed set of oceanographic scenarios.

This paper will present the background to the programme and a summary of the activities undertaken.