Upon arriving to the site, the problem was identified and a temporary solution (pictured here) was implemented. It is believed that sometime, possibly dating back to a trip in May 2013, a jumper for half of the phasing matrix was not reconnected to the proper place. Without this jump, half of the East radar was rendered useless on receive. So while all of the transmitters were putting power forward, only half of the received signals were being passed to the receiver front end. For those worried about the temporary solution, a proper square jumper, much like you might find on the inside of a desktop computer, was installed before the end of this trip.
In addition to setting the electronics to the proper mode, low-pass filters designed to keep out strong FM and TV broadcast signals were installed on every RF receive path between the two radars. These filters should help keep non-linear distortions out of the receive path since the signals, while out of band, are being picked up very well by the antennas.
With the two radars operating properly, some efforts were made to measure the time delays through the various RF coaxial cables and electronics. The time delays along the long length of coaxial cable connecting the antennas to the building were rechecked to ensure the time delay had not significantly changed. The last time delay measurement of these cables was taken during a trip more than a year prior to this trip and in a different season (May 2014). The measurements taken during this trip showed consistency with the previous measurement, so the accuracy of these numbers is believed to be good.
For the first time, a time delay measurement through the electronics was attempted. While this measurement has been done at other sites, the electronics at Fort Hays are slightly different making this measurement slightly more complicated. Some difficulty was found in making this measurement as well as time running slightly short. However, an initial first guess has been made which may lead to making sensible elevation angle data measurements with the West radar. Further analysis of the data needs to be performed though.
In addition to the work performed here, this trip was also an introduction to the new FHSU SuperDARN student intern, Brett Chrisler. While at the site, Kevin and Brett went over the basic checks of the radar electronics and the antenna array so that Brett can serve as the critical eyes and ears of the radar site. Additionally, some initial discussions lead Brett through the various science aspects of the SuperDARN radars so that Brett could begin working on a project using data collected at the Fort Hays radar site.
Fort Hays Tune Up Trip, Nov. 2015
By: ksterne on: Tue., Dec. 22, 2015 11:06 AM EST (6885 Reads)