NCSIDO - <!--#echo var="QUERY

30 May 2009 UTC

13:00 MDT - 19:00 UTC
NCISDO has been off-line for some time and will remain so for until further notice. I intend to reinvigorate the data collection in the future.
The table shown below (3 Jan 2005) has been updated and corrected (thanks for feedback from Rich Compeau of the University of New Mexico).

JAD

12 May 2005 UTC

08:00 MDT - 14:00 UTC
Increased the size (in pixels) of individual graphs to reveal greater detail.
Modified receiver channel table on graph page to include corresponding transmitter locations and range and bearing as seen by receiver.

JAD

8 May 2005 UTC

00:00 MDT - 06:00 UTC
Added frequency disperse spectrum graph to graphs display page.
Fixed a lingering problem with the 40700kHz channel so that NAU appears correctly now.

JAD

28 Mar 2005 UTC

11:00 MDT - 06:00 UTC
Updated SDR acquisition software to: (1) fix some bugs which caused the frequency binning to get mixed up and (2) add the capability to store time-averaged frequency disperse spectra. Although this new capability has not yet been fully developed the following two figures demonstrate the impact of this new capability. The first figure shows the frequency disperse spectrum obtained in one second of data acquisition. There is significant improvement in the reduction of 60Hz line noise associated with the relocation the antenna to the much quieter site. The second figure shows the equivalent grequency disperse spectrum obtained by co-averaging sixty of the one second spectra. The reduction in noise level and consequential increase in signal-to-noise are profound and reveal a number of previously unseen (at least at this Observatory) radio stations. Unfortunately, this increase in signal-to-noise is accompanied by an equivalent reduction in the time resolution of the spectrum. The time averaging period is adjustable and further experimentation will be performed with an eye towards optimzing the compromise between signal-to-noise and time resolution.
Many thanks to all those interested observers who provided helpful feedback which has led to this round of bug-squashing.

JAD

19 Feb 2005 UTC

5:00 MDT - 00:00 UTC
Changed observed frequencies to reflect changes in transmitting stations. See graph page for new station details.

JAD

9 Feb 2005 UTC

8:00 MDT - 14:00 UTC
Installed VLF antenna and data acquisition system on Table Mountain in north Boulder, CO.

JAD

23 Jan 2005 UTC

10:00 MDT - 16:00 UTC
Temporarily took down the VLF antenna and data acquisition system in anticipation of a move of it to a more quiet location.

JAD

8 Jan 2005 UTC

12:00 MDT - 18:00 UTC
Changed Y axis on all newly acquired data graphs to a fixed (30-90dB) scale to better show the relative intensities of the different channels.

JAD

3 Jan 2005 UTC

00:00 MDT - 06:00 UTC
Data acquisition has been restored for some time at a new location in Fort Collins, CO.
A multi-channel, Software Defined Radio (SDR) receiver has been implimented with ten simultaneous channels in operation. The following list details the center frequency and width of each channel:

The following figure shows the frequency-disperse spectrum taken from the SDR receiver in which the signals contained in the acquisition channels detailed above can be observed:

JAD

15 May 2003 UTC

00:00 MDT - 06:00 UTC - NCSIDO data acquisition halted
Data acquisition at NCSIDO has been terminated because of a planned move of the residence surrounding the observatory. This termination shall continue until a suitable, new location can be found.
Data archives, construction details, and other related materials shall remain available during this period.

JAD

29 March 2003 UTC

17:50 UTC - Changed data units from dBm to uVpeak. Reformatted data back to 17:00 28 March 2003 UT

JAD

3 February 2003 UTC

16:00-18:00 UTC - Repackaged receiver electronics with no planned or expected performance change

JAD

20 January 2003 UTC

05:00 UTC - Creation of log and initial entry.
Installed a single channel, variable center & width prototype receiver for testing.
Receiver set to 25.2kHz center frequency & 200-300Hz full width.
Receiver feeds to logarithmic demodulator but is not calibrated.

JAD

Operator Log