Phase 2 Waiver Requests and Programme Change Requests
To ensure the observing efficiency and flexibility of Service Mode observing, ESO has implemented a number of rules, procedures and limitations on programmes scheduled for Service mode. Typically, these have to do with OB construction, observing strategy, or instrument modes available.
In some special cases it is possible to admit some justified exceptions to these rules with a reduced operational impact. However, it is necessary that the exceptions have been reviewed and authorized by ESO well in advance. The Phase 2 Waiver Request procedure is the channel to make this possible.
Instrument independent conditions where a Phase 2 Waiver Request is needed
- OBs that will take longer than one hour to execute (except AMBER observations with more than one spectral band).
- Concatenated OBs prepared with P2PP3 that will take longer than one hour to execute (except CRIRES observation of science and telluric concatenated OBs which can be as long as 1.5 hour). Please note that justifications based on the reduction of execution overheads cannot be accepted, as sequences of OBs decrease the flexibility of Service Mode observing and thus the operational efficiency of the telescopes
- Concatenated OBs that have large angular separations between the OB targets (>75 deg) which would result in a very difficult scheduling.
- OBs that contain multiple instrument configurations. As an exception, multiple broad-band filters in a single OB can normally be allowed without a waiver, and for FORS2 up to two interference filters may be used in a single OB without a waiver. For CRIRES, OBs with multiple grating settings can be submitted without the waiver
- Delayed submission of Phase 2 material needed. This is admissible only under exceptional circumstances justified by scientific reasons, such as the need to wait for the outcome of another observing run before preparing the OBs. Users whose schedule prevents them from submitting their Phase 2 package by the due date are strongly encouraged to find a collaborator who can do it, rather than submitting a waiver request, as ESO cannot guarantee the prompt review and validation of Phase 2 packages submitted after the Phase 2 deadline.
- The time interval between succeeding time-linked OBs is < 1hr.
Additional conditions for Waiver Requests regarding VISIR
For VISIR, no waiver is necessary to ask for the execution of a concatenation of science and calibrator OBs, provided that the concatenation takes less than 90 minutes to execute. The individual science and calibrator OBs have to be less than one hour each.
Submission of service-mode OBs with PWV constraint values < 0.5 mm for the Q-band and smaller than 5 mm for imaging in the N-band requires prior approval of a Phase 2 waiver request.
Submission of OBs in which the half-cycle averaging flag is set to flase (used to save all half-cycle frames) requires prior approval by means of a Phase 2 waiver request.
Submission of service-mode OBs using the Intermediate Field (IF) pixel scale, or submission of service-mode OBs with a chop throw larger than 25", also requires prior approval of a Phase 2 waiver request.
Submitting Phase 2 Waiver Requests
Waiver requests should be sent to email@example.com. The Subject line of your e-mail should contain only your ESO Observing Run ID. For example:
All Phase 2 procedure waiver requests must be approved by ESO before Phase 2 package submission. Since a Waiver Request can take up to one week to process, please make sure to submit more than one week before the Phase 2 deadline. Waivers received less than five working days before the submission deadline will normally be rejected.
All waiver requests should include:
- what technical requirement you wish to override
- a brief (one paragraph) technical and/or scientific justification
The contents of the Phase 2 package must closely follow the project as described in the Phase 1 observing proposal (see Service Mode Policies. Any significant deviations from the approved programme (e.g. new targets, new instrument, new/different observing modes, etc.) must be approved by ESO before the Phase 2 submission process is completed. All approved run change requests should be summarized in your README file. Please note that change requests must imperatively be submitted, together with a scientific justification, through the dedicated web form.