Visibility Checks

CHEOPS can observe different parts of the sky at different times throughout the year (see Sky Visibility). The very first step when considering new targets for your proposal should be to familiarise yourself with the annual and monthly visibility maps, and get a feeling for which targets are within reach.

For Phase 1

For proposals in Phase 1, observers must use either the lightweight Visibility Tool or the streamlined Scheduling Feasibility Checker (SFC) to prove if and when their target is observable. Both tools are now faster & easier than ever, provided as zero-installation tools powered by ESA Datalabs:

To access ESA Datalabs, users need to register here and enter the invitation code "cheops-datalabs" 1-5 working days in advance of using the platform.

Both the Visibility Tool and the SFC allow you to check whether and when a target is visible to the instrument. You can also assess the impact that interruptions due to the satellite's passage through the South Atlantic Anomaly and Earth Occultations have on the target visibility. This serves to estimate the observing efficiency for your target, which is the fraction of time the instrument can collect photons from the target averaged over the observing window. 

(In case you encounter unforeseen problems with ESA Datalabs, you can also still find the repositories of both tools here: Visibility Tool on GitLab and SFC on GitLab. Note that we strongly recommend using ESA Datalabs, as these repositories will be deactivated in the future.)

For Phase 2

Note that for awarded proposals that need to draft their observation requests in Phase 2, observers must consult the SFC as the definite tool. Importantly, the SFC has been significantly modernised, now running in a fast & easy cloud-based environment powered by ESA Datalabs. If you reach Phase 2 and experience any hurdles with the SFC at that time, please do get in touch and the team will do their best to support you.