A sub-millimetre wave airborne demonstrator for the observation of precipitation and ice clouds

Sub-millimetre remote sensing instruments can provide critical information on cirrus clouds and an alternative way of measuring precipitation with a much smaller antenna than those which microwave sensors currently use. Two satellite concepts CIWSIR and GOMAS were proposed as ESA Earth Explorer missions; these were not funded, however they were recommended for an aircraft demonstrator. ESA studies have been performed to identify the optimum instrument and platform to demonstrate these satellite concepts. This paper reports on one of these preparatory activities; the design of a sub-millimetre wave airborne demonstrator for both ice cloud and precipitation observations which will be able to prove the feasibility of the scientific principles of both satellite missions. The paper will describe the derivation of the demonstrator requirements, consideration of the available platform and instrument options, the design of the selected concept, performance prediction and the outline of a proof of concept flight campaign. It will present the outcome of the study which describes a demonstrator design based upon the new Met Office International Sub-Millimetre Airborne Radiometer (ISMAR).