Guidelines for Submitting New Observing Modes to Arecibo

The Arecibo telescope is a versatile instrument with multiple receivers, backend processors, and telescope scanning modes. The Arecibo L-band Feed Array (ALFA) receiver adds a new dimension to the list of permutations because it can be rotated on its central beam-axis in order to compensate for the parallactic angle rotation of the sky over the course of a signal integration. The Arecibo instrument parameters can be combined in various ways leading to numerous observing modes. Observing modes are implemented at Arecibo through the Control Interface Module for Arecibo (CIMA). With CIMA, the observer selects receiver and backend configurations, as well as telescope scanning modes. Many standard, and non-standard, telescope scanning modes are implemented in CIMA. These include "standard on", "standard on/off", "drift scan", "drift & chase", "leapfrog", and others. Frontend versatility also provides possibilities with frequency switching, such as "smart frequency switching" which was developed for Galactic ALFA observations.

Often, an experiment will have special needs, and will require some combination of instrument setups and scanning modes which has not already been implemented in CIMA. In this case, the observer is encouraged to submit a proposal for a new observing mode. Proposals for new observing modes should be attached as an appendix to the scientific justification and submitted together with the observing proposal. The next proposal deadline at Arecibo is Feb. 1st, and the proposal instructions and cover sheet are available here.

Proposals for new observing modes will be evaluated by a technical review panel consisting of Arecibo technical and scientific staff. The technical feasibility will be judged, as well as the timescale for implementation. The technical review panel may reject a proposal on technical grounds, regardless of the scientific grade the proposal received. In such a case, the proposer will be invited to modify the observing requirements. This must occur before an experiment will be scheduled.

The following four items must be included in a proposal for a new observing mode. Proposals which are missing any of the following items will not be considered.

1. Brief, general description of the observing mode.

2. Specific advantages of this mode over other modes.
Indicate which specific problem it is addressing in terms of overhead, systematics, or other considerations.

3. Flow chart.
The flow chart should indicate the step-by-step procedure, including pointings, integration times, receiver frontend setup, and backend setup. Observers familiar with the Tool Command Language (TCL) may wish to submit the TCL code, or code snippet. This will help with the implementation, but it is not a substitute for the flow chart. The flow chart is required by the technical review panel in order to evaluate the observing mode.

4. Sky coverage diagram
The sky coverage diagram should show the pointings, or pointing tracks, for the entire experiment, as well as for an individual observing loop, where appropriate. The diagram should be in appropriate coordinates for the experiment. eg. Right-Ascension/Declination, Galactic Coords, or Altitude-Azimuth.

For questions or more information, please contact Steve Torchinsky (