How to create Finding Charts for Service Mode
In general, a finding chart has to be attached to each OB. Exceptions are possible for some instruments, in which case this is specified in the instrument-specific rules, which can be found by selecting the instrument from the pull-down instrument selector menu in the upper right of this web page.
General Finding Chart Requirements
Regardless of the instrument, finding charts must have all the following characteristics:
- Clearly indicate the Observing Run ID.
- Clearly indicate the PI Name.
- Clearly indicate the OB Name or Target Name, as used in the OB to which it is attached.
- The target(s) position(s) must be clearly indicated.
- The entire instrument field-of-view must be shown.
- North and East must be clearly indicated.
- The scale must be indicated by drawing a bar and writing the bar length in arcseconds or arcminutes.
- The wavelength range of the image must be indicated. Whenever possible, finding charts should have similar central wavelength to observations (e.g. DSS charts are often inappropriate for IR observations, e.g. near the galactic equator).
- The images should be negative, i.e. dark objects on light background.
- The output files must be in JPEG format and their size must be less than 1 Mbyte.
- Positions of spectroscopic acquisition reference stars, if any, should be marked.
- Spectroscopic finding charts must indicate the slit(s) position(s) clearly (unless slits are aligned along the parallactic angle)
Please verify that finding charts have sufficient quality and resolution. This can be done using p2 by attaching the finding chart and then clicking on the "thumbnail" version to see the full size version displayed in your browser.
Please read the P2 finding chart tutorial for a detailed description on how to attach finding charts to OBs.
How to create finding charts
p2 Finding Chart Generation service
A Finding Chart Generation service, called p2fc, is integrated into p2. It allows the automated, non-interactive creation of finding charts for individual or multiple OBs at the push of a button for almost all of the current VLT and La Silla instruments that require finding charts. A detailed description and instructions for usage are available in the dedicated p2fc Finding Charts page.
A command line interface to p2fc is also available, via the Python p2api, allowing control over many of the characterisitics of the FC generation that are not possible in the single click implementation available in p2.
Other Finding Chart tools
Alternatively, valid finding charts can be produced with any software tool able to produce output files in JPEG format. For users who do not use the p2 finding chart generation service or instrument specific preparation tools like FIMS or KARMA, ESO recommends the use of the SkyCat-based finding chart tool. This tool provides another user-friendly interface to easily produce finding charts with the general characteristics described above.
Skycat, including the ESO Finding Chart Plugin, is now available from the ESO software repositories (see below), package name eso-skycat.
Additional rules for FORS charts
No Finding Charts are required for OBs observing moving targets, ToO or RRM OBs, Calibrator OBs, or pre-imaging OBs (although Finding Charts may be attached to such OBs, if deemed helpful). Finding Charts are mandatory for all other OBs.
All FIMS based observing modes (OCC, MOS, and MXU) require finding charts mandatorily generated with the FIMS tool.The finding chart plugin distributed with the FIMS software provides a convenient way to also comply with the above general rules, although using p2fc inside p2 is easier in most cases.
Please include the following requirements:
- Use the label option of the FIMS tool to get the FORS specific labeling of the finding chart automatically correct (i.e. this gives the coordinates of the field center, the rotator angle, indicates the field of view, the reference and target objects, the slit geometry, wavelength coverage etc.)
- For FIMS based OBs the finding chart must contain an overlay of the full FIMS field clearly showing the reference stars and the slit geometry.