The EChO core science will be based on a three tier survey, each with
increasing sensitivity, in order to study the population of exo-planets from
super-Earths to Jupiter-like planets, in the very hot to temperate zones
(temperatures of 300 K - 3000 K) of F to M-type host stars. To achieve a
meaningful outcome an accurate selection of the target sample is needed. In
this paper we analyse the targets, suitable for EChO observations, expected to
result from a sample of present and forthcoming detection surveys. Exoplanets
currently known are already sufficient to provide a large and diverse sample.
However we expect the results from these surveys to increase the sample of
smaller planets that will allow us to optimize the EChO sample selection.Comment: Submitted to Experimental Astronom