VLA Site Stand-Alone Monitoring Systems Data

Two spectrum analyzer based RFI monitoring systems are in use at the VLA site:

The W8 monitor taps off of the RCP output of the EVLA L-band and VLA P-band receivers of the W8 antenna, and defaults to 1-2 GHz, although other frequency ranges within L or P band may occasionally be selected for monitoring. The W8 plots show 24 hours of recorded power data, as frequency vs. time plots, with the power intensity indicated by grayscale shading.

The RF-EMS monitor is a stand-alone system currently using a commercial UHF Discone antenna on a 54 foot tower. The default coverage is VLA P-band (300 - 350 MHz), although other frequency ranges from HF through C-band may occasionally be selected for monitoring. The RF-EMS plot format is similar to W8 plot format summarized above.

Sysquick plots are historic cross-correlation plots generated using the original VLA correlator. Sysquick plot format is frequency vs. amplitude, and covers VLA bands P through K.

Additional details on each monitoring system, as well as current and archival data plots may be found at the links below.


Additional details on the W8Mon plots are available online.

L-band (1.2-2.0 GHz)
P-band (300-350 MHz)


Additional details on the RF-EMS plots are available online.

C-band (4.0-8.0 GHz)
S-band (2.0-4.0 GHz)
L-band (1.2-2.0 GHz)
P-band (300-350 MHz)