Delta Use Case for EVLA Observing - Polarization, v2 Bryan Butler 2004-Aug-11 As described in the main use case document, subsequent use cases from that one will be presented as "delta" use cases - only providing steps that are different from those in the main use case. This is the first of these delta use cases, describing continuum observing at an intermediate frequency (X- or C-band), but for an observation that is concerned with polarization. I. Proposal Preparation and Submission ... 4. necessary resources, including configuration, frontend(s), backend (correlator) setup. Here, a specification must be made on which polarization products will be recorded. ... 5. source information: position, flux density, size, polarization properties ... 7. time needed a) in order to figure out how much time is needed, the user may do one of: ... (3) for polarization observations, the observer must input a required circular or linear polarization accuracy in both fractional amplitude and in the accuracy of the angle of linear polarization, if linear polarization is required (sensible defaults should be provided). This may drive the required observing time, along with necessary calibrations and accuracy. b) for polarization observations, there may be constraints on the time needed based on parallactic angle coverage. II. Observation Preparation ... C. the user then specifies the following: ... 2. a source list, containing all of the sources of interest ... g) a sequence of observations - including the cycle time between source and phase calibrator, and when to observe the flux density and, if needed, polarization angle and instrumental polarization calibrators. Note that sensible defaults should be provided, of course. ... i) for polarization observations, associated polarization angle calibrators (might be the same for many sources) j) for polarization observations, associated instrumental polarization calibrators (may be the same as the phase calibrators specified above, but for polarization observations, the requirements are slightly different). III. During Observing nothing beyond the default use case... IV. After Observing (Data Access) nothing beyond the default use case...