Specifications

3. Frequency-domain analyzer (max-hold, median, mean). By antenna, or by beam. Variable
spectral resolution and integration time. The command line version will provide the same
information, but in numerical form only and without continuous updating.
4. Time-domain analyzer. By antenna, or by beam. Variable bandwidth and integration time.
The command line version provides same information, but in numerical form only and without
continuous updating.
5. Time-frequency analyzer (i.e., spectrograms). By antenna, or by beam. Variable temporal and
spectral resolution. The command line version provides same information, but in numerical
form only and without continuous updating.
6. Sky map. Provides a low-resolution image of the sky in brightness temperature at the se-
lected frequency, location, and time. Can be set to update in near-real-time. Provides also
position (RA/Dec as well as current Az/El) of the Sun, Sag A, Cas A, Cyg A, and Tau A.
Predicts antenna temperature. The command line application provides same information, but
in numerical form only and without continuous updating.
7. Command line “help” application; essentially, “man” pages for all MCS commands.
6 User Observing Paradigm
The term “observation” may have multiple definitions in the context of an LWA station. In this
section, we define an “observation” as the allocation of LWA station resources over a specified time
period to a user, for the purpose of collecting science data. The sequence of events for an observation
are as follows:
1. The user plans the observation. Parameters that must be determined include start and end
times; configuration (choice of beamformer, TBN, or TBW, for example); pointing vs. time,
center frequency, bandwidth, and integration time for specified beam(s); and so on. Users will
not normally need to know site specifics or details of the digital signal processing to plan an
observation. For example, to define a beam pointing, the user will have to provide RA/Dec
and center frequency, but not Az/El, per-antenna delays, or FIR coefficients.
2. The user defines the observation using the on-line or off-line application software described in
Section 5, item 2. If the off-line application is used, the process must be completed using the
on-line application.
3. MCS determines if the observation is allowed. For example, if the observation is part of an
approved proposal, MCS compares the observation request to information from the approved
proposal. MCS also determines if the observation is possible; i.e., within the capabilities of
the station, taking into account current status such as subsystem failures. The observation is
then either accepted or rejected.
4. MCS conducts the observation. The observation can be monitored in near-real-time as de-
scribed in Section 4.
5. Data acquired from the digital processing (DP) subsystem will be r ecorded as explained in
Section 3. Metadata associated with the observation will also be recorded. Primary source
of metadata will be MCS log entries p er taining to the observation (indicating progress of the
observation and error conditions (if any) encountered) and station “state” information that
may be needed to analyze or interpret the data at a later time; for example, details of station
configuration, array geometry, maintenance conditions, and so on.
6. At some point after the observation is completed, the user is responsible for offloading data
and metadata; see Section 3.
“Fire and forget” operation will be supported; that is, users will not be required to be logged in
order for commands (including observation commands) to begin or complete execution.
5