ESA Science & Technology - EChO Radiometric Model Description

Publication date: 17 December 2013

Authors: EChO Team

Year: 2013

Copyright: ESA

Reference: SRE-PA/2011.040/, Issue 3, Revision 2

This document provides a detailed description of the ESA EChO radiometric model. This model will be used to validate the mission requirements, which have, in turn, been derived from the science requirements. The model provides the means to calculate, for a given host star/exoplanet target:

• The SNR that can be achieved in a single primary transit
• The SNR that can be achieved in a single occultation
• The number of transit/occultation revisits necessary to achieve a specified SNR
• The total number of revisits that could be achieved during the proposed mission lifetime.

The radiometric model will be used to establish whether proposed samples of known or model targets can be observed to the signal-to-noise ratio (SNR) called for in the Science Requirements Document, with mission requirements given in the Mission Requirements Document (i.e. within the mission lifetime, with the observation efficiency required and the minimum design requirements), and to confirm the minimum design requirements for the mission.