Introduction

The OPT, SCT and RCT abbreviations were introduced in the previous section. When referring to the OPT in the remainder of this document, most of the time it is implicitly referring to the tool that creates a sequence of observing scans. On the other hand, when we refer to the OPT web application we specifically refer to the combination of tools consisting of OPT, SCT and RCT.

The use of the term (re)source is short-hand for the text source and resource: the sentence applies to both source and resource. Similarly, project (etc.) allows us to avoid having to write project, program block(s), scheduling block(s) and scan(s) which otherwise would make sentences confusing. For program block and scheduling block we will use PB and SB, respectively, or blocks when we mean either or both.

We will further use PST and PSC to refer to the Proposal Submission Tool and Proposal Selection Committee, which have some interaction or influence on what goes on in the OPT web application. Finally, we will use OSRO to indicate anything related to the Open Shared Risk Observing period, starting in the spring of 2010, for which the full capabilities of the new EVLA WIDAR correlator are not yet available.

The current (January 25, 2010) purpose of this document is to provide help to the individual preparing EVLA observations with the new WIDAR correlator during the Open Shared Risk Observing (OSRO) period. This document consists of an introduction to the new Observation Preparation Tool (OPT) web application, hints and preliminary cookbook-like approaches to create a successful observing schedule, and contacts for further assistance. This document is not suited to learn, nor intended to teach, observing strategies and good observing practices; it is assumed that the individual either has prior knowledge of this, or will educate himself/herself on this subject before finalizing an observing schedule. The Observational Status Summary and other EVLA documentation (http://science.nrao.edu/evla/) are great resources with further references. The target audience is the successful proposer at the October 2009 (or later) deadline that proposed for EVLA array observations with the WIDAR correlator during the OSRO period. Depending on progress of the WIDAR commissioning, user feedback, upgrades to the software and new capabilities, this manual on the OPT web application scheduling tool may be updated, expanded and made available for other observations in the near future.

An observing schedule using the EVLA electronics and correlator is made through the OPT, the Observation Preparation Tool web application. It consists of a description of creating an observing run, a Scheduling Block (SB), which is made up of a sequence of observing scans. To make full use of the OPT, it is usually necessary to pre-define (i.e., enter) sources to be observed using the SCT, the Source Catalog Tool, and to possibly pre-define the frequency and correlator settings to be used using the RCT, the hardware and instrument configuration “Resource Catalog Tool”. This document should aid in creating source and resource lists, and in creating the final observing schedule (a Scheduling Block). Alternatively, if no user catalogs are defined, then one can resort to observing calibrator sources using standard correlator settings, although using these catalogs only may be rather restrictive in scientific discovery space. Once familiar with the concept, one will probably recognize some similarity with the observe list, source list and user defaults as previously used in Jobserve; there are, however, major differences.