Wallops Island Transmitter Overhaul - March 2015

By: ksterne  on: Fri., Apr. 10, 2015 09:12 AM EDT  (2782 Reads)
Early in March 2015, Kevin Sterne and Mike Ruohoniemi of Virginia Tech and Drew Knuth and Ethan Miller of John Hopkins University's Applied Physics Lab met at the Wallops Island SuperDARN site to assess the electronics and the condition of the site. This trip would serve to prepare for a larger trip during the summer where more effort will be put into enabling elevation angle data to be collected by the radar. As well, this trip would take care of a few outstanding issues including a check of the transmitters and radar control electronics.

VT Crew makes repairs to the Kapuskasing Radar

By: miker  on: Thu., Oct. 16, 2014 10:40 PM EDT  (2523 Reads)
Kevin and Mike from Virginia Tech traveled to northern Ontario October 2 - 8 to visit the site of the Kapuskasing SuperDARN radar and make repairs. A number of technical issues were addressed including the performance of the interferometer array. By the conclusion of the trip all 15 available transmitters were functioning although a couple were out on receive owing to a lack of a needed spare part. The sensitivity of the radar has been significantly improved, in time for the first dark moon campaign period at the end of October. A slow internet connection continues to be worked on. This was the first meeting of the VT crew with the new site operator, Mr. Ghislain LeBouef. Ghislain participated in the repairs and arranged discussions with local vendors.

Photo: Kevin makes connections to the low-power T/R switch in a transmitter.

Fort Hays Trip, May 2014

By: ksterne  on: Thu., July 03, 2014 10:33 AM EDT  (2980 Reads)
In early April, the returns from the Fort Hays radars changed drastically. The problem began on April 4th with very noise signals being recorded on both radars. The original problem seemed to begin with a blown fuse in the PTS160 synthesizer. However, in the process of replacing the fuse, some of the connections on the back of the QNX6 computer must have come loose. In phone and e-mail conversations with Ryan White, FHSU SuperDARN intern, it seemed as though something was wrong with the RXFE or the way the RXFE was being controlled. In the end, it seemed as though a touchy connection between one of the outputs of the QNX6 computer and the control cable was causing the RXFE to not keep the correct settings. A replacement for this connection was put together and a trip was made to the site to repair this connection as well as do an assessment of the site.

Blackstone Trips March/April 2014

By: ksterne  on: Tue., Apr. 15, 2014 04:01 PM EDT  (2687 Reads)
After the overhaul of electronics at the Blackstone site in 2011, a better way of controlling the phase beam steering was introduced with a modified version of what the University of Saskatchewan radars are using (Saskatoon, Inuviuk, Prince George, Ranken Inlet, and Clyde River). This design makes use of direct digital synthesis (DDS) chips and a micro-controller to create the phase shifts as well as the control signals that are needed to run the radar. The modified design was purchased from the University of Saskatchewan and assembled in the Virginia Tech lab between 2013 and 2014. During the end of March and a separate trip on April 8th, the modified Univ. of Saskatchewan design was installed at the Blackstone radar. Also during these trips, measurements and calibrations were done in order to reconfirm the tdiff to be used in the hdw.dat.bks file.

In the end these calculations did not result in a new line to the hdw.dat.bks file from the previous change on July 9, 2013. As well, the Blackstone radar began recording elevation angle data late in the day on March 27th, 2014.

Fort Hays Trip, Nov. 2013

By: ksterne  on: Fri., Nov. 15, 2013 02:08 PM EST  (3066 Reads)
Following the trip from April/May 2013, a persistent problem developed with the QNX computers network interface cards. The cards would randomly lock up and not accept any new connections on a time scale of 12 hours to a couple of days. To bring the Fort Hays radars back online, a hard reboot was performed. However, after several months of this type of treatment, the linux computer failed.

During this trip, a new linux computer was taken out to the site and successfully installed. This computer is using radar operating software provided by Jef Spaleta's (University of Alaska Fairbanks) github repository. Using the github software development, future changes to the code will be tracked and implemented at the radar site.

Goose Bay Trip - Sept. 2013

By: ksterne  on: Tue., Sep. 24, 2013 04:52 PM EDT  (3409 Reads)
Sept. 26 Update

Today started off well with much improved weather as the sun was out most of the day. This morning also started off well with tidying up the equipment shack a little bit as well as mapping out the signals throughout the entire receiver front end board. Signal levels were measured at each stage so that an accurate drawing of the receiver front end board design can be made upon returning to the lab. In addition, measuring signal levels as almost every stage also ensures that all of the components are working properly and haven't been damaged. The shack was straightened up a bit with the SmartUPS system being brought up off the floor with the help of an old tool box. Likewise, the main QNX computer and timing computer were brought up off the floor about half a foot with the use of some scrap wood laying outside of the building.

This afternoon's work turned more towards the transmitters in an effort to get a few more transmitters going. In the end, no repairs were made, but several problems were more clearly identified. With a bit of switching parts or feeding RF paths to different places, 14 transmitters were left running as two transmitters were found to not be good. This is the maximum number of transmitters that could have been left running as two antennas along the main array have bad feeder cables.

Otherwise, a lot of pictures were taken and things left so that future repairs/checks can be coordinated with our local contact. For being almost 30 years old, the site is looking and running well!
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