A new website displaying news and information is being developed by the Virginia Tech SuperDARN group. The principal authors are Virginia Tech undergraduate Ethan (Duke) Hill and Dr. Bharat Kunduri. Several new features are available there including a one-click real-time display of data from the Virginia Tech radars (derived from the University of Saskatchewan real-time display) and the draft of a website where users can easily generate an Acknowledgement statement for use of radar data. The link to the website is

http://vt.superdarn.com

Real-time display: 'Radars v Realtime Data'

Please note that this is an active work area with offline periods likely!

Do you want to be in the shadow of the next two US solar eclipses? We need students for a project sponsored by NASA Space Grant to live-stream the April 2024 Total Solar Eclipse from the edge of space. An information session will be held (with light refreshments) on Monday Dec. 12th 3-4pm in Goodwin 145 and on zoom. The project will officially kick-off in January, and no prior experience is required to join the project. Through this project you will learn the fundamentals of high-altitude ballooning and work on the design, assembly, verification, and testing of project equipment including a ground station, Raspberry Pi camera payload, cutdown mechanism, data collection units, tracking systems, and payloads of your own design.

If you think you might be interested in this project but cannot make this time, still fill out the interest form (https://forms.gle/NNJnN4jvhEf26wmu7) so we know to reach out to you before next semester.

We hope to see you at the information session!
Cheers,
Ginny Smith and Kevin Sterne

Following on a trip earlier this month to prepare the antenna poles meant for a dual radar build in Iceland for shipping, a Dartmouth College - Virginia Tech crew returned to the Blackstone radar site to actually load the poles and related hardware into two shipping containers. The trip took place June 14-16 under difficult conditions of high temperature and sometimes punishing humidity. The PI for the Iceland radar build, Simon Shepherd from Dartmouth College, directed the loading. From Virginia Tech four crew members returned for this trip (Mike Ruohoniemi, Kevin Sterne, Ian Kelley, Mark Higgins) and were joined by undergrad John Fiorini. The photo shows the crew triumphant after loading the second container with antenna base sections. On June 21 Kevin returned solo to the site to oversee pickup of the containers by a trucking company. The hardware is now on its way to Iceland to complete the 4th MSI SuperDARN radar build.
Photo credit: Ned Jones (Virginia Tech Southern Piedmont Agricultural Research and Extension Center)
In photo from left to right: Kevin, Mark, Simon, Ian, Mike, John

A combined crew of SuperDARN PIs, research staff, and students visited the Blackstone site June 6 - 10. The goal was to prepare antenna poles and hardware for shipment to Iceland where they will be incorporated into the build of a new dual radar site at Pykkvibaer. The equipment has been stored at the Blackstone site for about ten years as a site was sought to complete the build of radars under the NSF Mid-Sized Infrastructure (MSI) program. The new radars will effectively replace the previous radars located at Stokkseyri and Pykkvibaer. Much woodworking and heavy lifting was required on this trip. The DC crew counted Simon Shepherd (PI) and undergrad Nathaniel Alden while the VT crew counted Mike Ruohoniemi (PI), Kevin Sterne, grad student Ian Kelley, and undergrad Mark Higgins. A second visit is planned to relocate the equipment stacks into shipping containers for delivery to a shipyard.

Following the completion of the move of the VT SuperDARN group to new on-campus quarters, the group website is now undergoing a thorough updating, a process that may take several months. Temporary interruptions in some services are possible. If you have a time-critical need for a product that is unavailable, please contact a group member listed under 'Contact/Visit Us'.

New banner design credit: B. Kunduri

Over the course of August and September of 2020 the SuperDARN radar group, with its offices and lab, re-located from a building in the Corporate Research Center on the outskirts of Blacksburg to a location near the heart of campus. This was part of the move of the Center for Space Science and Engineering Research (Space@VT) which counts groups in the ECE and AOE departments. Owing to covid-19 circumstances actual activities in the new areas remain limited with most people accessible by email and Zoom. The new quarters for the SuperDARN group are located on the 3rd floor of Durham Hall. Details of our new mailing address are given in 'Read More'. We look forward to welcoming visitors in our new quarters!

Dr. Jianjun Liu from the Polar Research Institute of China (PRIC) made a working trip to the SuperDARN Blackstone site on January 13, 2020 and assisted in bringing this radar back on line. The crew included SuperDARN regulars Kevin Sterne and Mike Ruohoniemi and Virginia Tech undergrad Ian Kelley who performed significant diagnostics on the damaged parts. The PRIC is a member of the international SuperDARN collaboration (PI: Dr. Hongqiao Hu) and operates a SuperDARN radar at the Chinese Antarctic base at Zhongshan Station where Jianjun wintered over during a 14 month stay. He has been visiting the VT SuperDARN group since December and will return home later this week. The photo shows (from left to right) Jianjun, Kevin, and Mike standing in front of the Blackstone electronics.

Photo credit: Ian Kelley

On April 25 a group of visitors was led by Kevin Sterne to make a tour of the Blackstone SuperDARN radar. Drs. Nozomu Nishitani and Tomo Hori and graduate student Kento Oya from ISEE Nagoya University were joined by Dr. Erxiao Liu from Hangzhou Dianzi University. The photograph shows the Japanese visitors with Kevin and towers of the two arrays and the equipment shelter in the background.

(Photo credit and missing from photo: Dr. Erxiao Liu)

During the installation of the low loss coaxial cable in Oct. 2015, only the main array had new ground coax cable installed as time ran out to finish installing ground coax cables to the interferometer array. With a push from Simon Shepherd at Dartmouth College to get more radars collecting elevation angle, a trip to the Kapuskasing radar was planned for Kevin Sterne, Paul Kennedy, Mike Ruohoniemi and Simon Shepherd. In addition to installing the ground coax cables, the condition of the antennas along both array and the transmitters would be investigated and checked as the last service trip was the Oct. 2015 trip. Lastly, this trip was necessary to install signage around the site in order to comply with safety standards with the Canadian government.

With the visit of FHSU student intern Kelly Strecker and with the repairs of some transmitters from the May 2018 trip, this trip to the Blackstone radar introduced Kelly to more radar hardware and allowed the installation of the transmitters. The goal with the transmitters was to get all of them firing as all of the antennas were repaired earlier in the year. With the two recently repaired transmitters, the radar was left running on all antennas at the end of this trip. However, two additional transmitters were found to not be running so these were brought back to the Blacksburg lab for repairs. These transmitters will be spares at the site once repaired and returned.

In addition to these items, a check of the electrical lengths along the coax and inside in the electronics was performed as gathering correct elevation angle data has become an emphasis across SuperDARN. The time delay was found to be close to previous values, with some small differences. This new difference will be reflected in the hdw.dat file for Blackstone.

After a trip in March 2018, the next steps in making repairs to the antenna array would be the removal of the old reflector wires as well as the upper and lower horizontal guy wires. A trip was made to the site in mid-May as the availability of personnel and a lift from Wallops Island’s facilities coincided at this time. Thanks needs to be given to Philip Smith with NASA/Wallops Island for coordinating a lift for us. A majority of materials ordered following the March 2018 trip would also be on hand by this time which would facilitate the initial steps needed for the repairs.

Following the April 2018 overnight trip to Blackstone when many of the transmitters were repaired, a trip was needed to make some repairs to the antenna array. On leaving the radar during the April trip, there were more transmitters in working condition that there were antennas. A trip was organized in order to make repairs to the antenna array including antenna feeder cables, antenna wires, baluns, resistor boxes, and reflector wires. Dr. Mike Ruohoniemi, Paul Kennedy, and Kevin Sterne made 2-day trip to the site in order to make these repairs and investigate any other issues along the antenna arrays.

Following the March 2018 day trip to Blackstone, it was noticed that about 5 to 6 transmitters were not on or running for various reasons. As time did not allow of any kind of electronics checks during the previous trip, this trip was made by Kevin Sterne and Dr. Mike Ruohoniemi to review and make repairs on the electronics inside of the building. It was hoped that any outdoor work on the antennas could be performed during this trip, but logistics did not allow for making it worth renting a high-lift. In addition, the newly installed wireless hop system would be re-checked to see about improving the connection as it was still experiencing some minor problems despite staying up for the majority of the time.

Following an extended period of problems with the network connection to the site, a trip was planned after some new equipment was purchased to replace the aging wireless bridge system. The network connection has been a problem since the site was constructed, and in particular since the installation of new radios in 2011. However, through late 2017 and early 2018, the network connection was mostly down leading to long backlogs of data. To resolve this problem, new antennas, mounting hardware, and Ethernet cable were taken out to the site along with replacement radios that were in the lab. This trip was made while Mike and Kevin were coming back from Wallops Island in the two days prior. Of course, upon arriving to the site, the network connection was working.

After examining the condition of many of the radars, it was determined that a major effort should be put into repairing the antenna array at Wallops Island. This effort also follows work done by Mike and Ethan along with Rob Pfaff to get the grounds around the antenna arrays cleared out and maintained in late 2016 and 2017. During this trip, Mike and Kevin took stock of what exactly needed to be repaired on the antenna arrays and get some order sheets going. With additional time, the RF performance of the transmitters and antennas would be measured to quantify the amount of repairs needed. Dr. Ethan Miller and Dr. Patrick Dandenault from APL joined us for a day to review the antenna array repair project.

Following the May 2017 trip, the west main reflector array still needed to be rebuilt with a little over half of the wires still needing to be strung up. This trip would also serve as the last tune up of the radar prior to the Great American Solar Eclipse of 2017.

Following an ice storm in January 2017 and an assessment trip in Feb. 2017 a major trip was made to make repairs to the West main antenna array reflector so that the west radar was fully functional well prior to the August 2017 solar eclipse.

Following the November 2016 trip, the correct size (5/8” rod) of CADweld mold was ordered in order to complete the grounding work that had been long overdue. However, winter cold and wet set in and so the work could not be completed until better temperatures arrived. In the month prior to this trip the internet connection to the site had been out for several days if not weeks at a time going on 3 to 4 weeks. So with these issues, a trip was planned to take care of these issues and make sure the radar was running fairly well (with known issues on the antennas).

Hays, KS sustained a major freezing rain and icing event in mid-January 2017. Following reports from FHSU student intern, Brett Chrisler, of significant damage to the West main antenna array a trip was made by engineer Kevin Sterne to assess the damage at the radar site. As well, this trip would be allow for preparations to be made for a future repair trip.

After many, many years, the grounding work along the antenna poles had not been completed. On each antenna pole, a ground rod had been driven into the ground and a copper busbar had been attached under one of the bolts on the base of the pole. So a trip was made to the site by Kevin Sterne, Shibaji Chakraborty and Muhammad Rafiq to complete the grounding work.

Brett Chrisler, the Fort Hays State University student intern, made a trip to the Blacksburg SuperDARN lab in early July. During his trip, Brett would review research areas that he can explore with our group as well as to make a trip to the Blackstone radar to show him another style of SuperDARN radar and gain more hands-on training.

The replacement of the ground coax is a longstanding project that needed to be completed at Goose Bay. In preparation for this project, a work order was placed with Serco to clear all the trees and brush that have taken over the antenna array grounds over the years.

Shortly before the winter break, the internet connection to the radar site went down. Being patient since the availability of people to check on it would probably be low, the connection remained off over the two week winter break. However, our local contact was able to check on the connection for us and noted that the Power-over-Ethernet (PoE) power supply had melted and thus the internet connection was broken. The damage to the PoE unit and the RJ45 connector can be seen in the picture. In order to keep the linux computer’s hard drive from filling up, a trip to the radar site was made to restore the connection. In addition, this trip would be used to install the newly acquired and configured linux computer.

With two visitors from the National Space Science Center (NSSC) in China visiting the Blacksburg lab for two weeks, a trip to the radar site was planned in order to show the visitors the operations and common testing of a working radar site. The visitors, Jiaojiao Zhang and Ailan Lan, as well as Muhammad Rafiq (VT doctoral candidate) and Kevin Sterne made a trip to the site in December. This trip would also serve as wrapping up some loose ends before the end of the year. These loose ends included reinstalling the SmartUPS that needed a new battery after it failed over the summer. Lastly, the Reverse Beacon Network receiver would be disassembled and taken back to the Blacksburg lab as the equipment had been setup on a temporary basis for testing at a radar site. The receiving antenna on top of a stack of antenna poles shortly before it was disassembled is seen in the picture.

Following the August 2015 trip to the Fort Hays radar, it was noticed that the East radar appeared to be less sensitive than the West radar. Prior to the August trip, it was believed that this might be due to operating on fewer antennas on the East radar as compared to the West radar. However, with the major repairs done to replacing the antenna feeder cables during the August trip this reason would not apply. So a trip was made by Kevin Sterne to test other a few other theories on why the East radar was less sensitive. As well, during this trip efforts would be made in making measurements to understand the time delays through the electronics. These efforts would help the radars begin to collect sensible elevation angle data.

As part of an outstanding project to upgrade accessibility to the array as well as to improve the performance of the radar, the Kapuskasing radar had two major projects completed within the last couple of months. The first of these projects was improving the current road from the radar building to the main array road as well as creating a brand new road from the main array road out and along the interferometer array. The second project was replacing the aged coaxial cables that carry signals from the antennas to the radar building which was performed by Kevin Sterne and Mike Ruohoniemi in mid- to late-October 2015.

Over the Summer 2015 in talks between VT SuperDARN and University of Calgary groups, it was noticed that there was a gap in riometer coverage in the Labrador area. The University of Calgary group was interested in installing a riometer at the Goose Bay SuperDARN site in order to fill in this gap. After a few months of planning and coordination, a trip was made by Kevin Sterne (from VT) and Craig Unick (University of Calgary) to the Goose Bay site to install the riometer.

After a decrease in sensitivity on the Fort Hays radars, Kevin Sterne and Mike Ruohoniemi made a trip the week of August 16th to the 22nd 2015 to Hays, KS in order to assess parts needing repairs and perform what repairs could be completed. In the weeks prior to this trip, FHSU student intern Ryan White reported a few wires hanging down along the antenna arrays as well as problems with the antennas. Also, in the weeks or up to a month before the trip, one of the computers at the site began locking up.

A quick day trip was made by Kevin Sterne and Deven Chheda on March 27th, 2015 in order to install some repaired transmitters and give a look at the site to see how things were going. This trip was originally planned after an extended network outage as well as a fear that one of the computers at the site had gone bad. However, in the days leading up to the trip the network connection as well as the issue with the computer were corrected. This left us with smaller but also important issues to complete during this trip. One of these was to install two of the four transmitters that were being worked on in the Blacksburg lab. These two had been repaired and were ready to be installed back at the site. As well, a range calibration was performed during this trip as it was noticed that sometime in mid-September, the radar's range appeared to be off. As well, this would be Deven's first trip to a SuperDARN site, so the operations and systems were explained to Deven.

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.

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.

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.

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.

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.

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!

Starting a trip update here towards the end of a trip by Mike and Kevin to the Goose Bay radar. We found, as suspected, a bad 48V power supply upon arriving to the site. We also found several towers needing struts to be put back up or just tightened. A surprising find was that the zip-ties holding the feeder cables on going up the pole had broken on many of the main array antennas up the tower. With the 50' of coax hanging free in the wind, many of the connectors at the base of the towers had been pulled out.

So far this trip, the bad 48V supply has been removed and will be packed out for repair or replacement. Lots of antenna work has occurred tightening up struts on the towers as well as replacing connectors at the base of the towers. Also, all of the transmitters have been diagnosed or tested on transmit and only a few transmitters were found to be not working properly. With a few good transmitters as well as antennas, the radar began operating again Tuesday evening!

We may have another trip update before Kevin leaves on Friday, the 23rd and Mike leaves Saturday, the 24th. Otherwise, stay tuned for a more detailed debrief of the trip!

August 15, 2013 Update

Our data archive has now been fully transitioned over to the new system. SuperDARN data contained on the new system can be found at:

http://vt.superdarn.org/tiki-index.php?page=Data+Inventory

We hope in the coming weeks to also transition our webserver as well as data processing and plotting computer over to new computers.

A solo trip was made by Kevin Sterne to the Fort Hays radar site between April 29th and May 3rd, 2013. During this trip, a number of long outstanding issues would be taken care of as well as a pressing matter of boxing up and shipping out all of the leftover pole hardware. This pole hardware included all of the nuts, bolts, and washers necessary for putting the poles together. Other outstanding issues were a complete recalibration and reprogramming of the phasing cards for both radars as well as some other software upgrades.

With the new RBSP mode camgpaign officially 3 months into operations on the SuperDARN radar, a look was taken as to how much time this mode was being run on a few radars. Data was collected using the new CPID Inventory and recording the number of soundings made on a radar for each month. Here the number of soundings doesn't exactly take into account the amount of time the mode was run, but it is a close approximation. The results for this analysis for Blackstone can be seen in the picture to the left.

Despite heavy snows the night before in the Blacksburg area, a day trip was made out to the Blackstone site in order to finally meet up with NSF frequency managers Andy Clegg and Tom Gergely. This trip would also include recalibrating the amplitudes of the signals being created in the phase generator in the radar control electronics.

Kevin Sterne and Ray Greenwald made a trip to the Blackstone radar on Nov. 29, 2012 in order to investigate the range differences between a normalscan based and a tauscan based control program as well as to install recently acquired custom filters and modify the receiver front end. The range differences had been noticed when running the new rbspscan in support of the Van Allen Probes (formerly Radiation Belt Storm Probes). The new filters and redesign of the receiver front end would allow for cleaner mixing and filtering of the received RF signal.

Ray Greenwald and Ethan Miller of John Hopkins University's Applied Physics Lab made a maintenance trip to the Wallops Island radar after a brief observation of the site after Hurricane Sandy. It was reported that several wires were down and not many transmitters were working after the hurricane passed through the mid-Atlantic region. Ray and Ethan's trip was to make repairs in order to bring the radar up to full operation.

An updated version of "Steering SuperDARN Radars" has been uploaded to VT SuperDARN/Tutorials. This version contains additional information on the University of Saskatchewan DDS-based phasing matrix.

During a phone call with Kent White, local operator for the Goose Bay radar, it was determined the problem with the Goose Bay site that has resulted in bad/non-existent data for the past few weeks. Kent track the problem down to a bad power outlet that seemed to be causing power bars to fail one after another. Using a new power bar plugged into a different power outlet, the radar has been running for several hours and has been collecting sensible data. Many thanks go to Kent for solving this problem without requiring a trip from someone at the SuperDARN lab at Virginia Tech.

The return of normal operations at the site paves the way for this radar to begin to participate in the RBSP operations that other Virginia Tech SuperDARN radars have already started.

A day trip was made by Kevin Sterne and Fort Hays State University student intern, Randy Oullette, to the Blackstone radar in order to investigate the network connection outage and restore the connection. Also on this trip, a different style of electronics would be introduced to Randy as he had only worked with the MSI style of radar control electronics.

Tuesday, Sep 11: Bill reports that Adak is on the air! In his words: 'I am pleased to announce that we had "first light" on both halves of the Adak system this afternoon. We brought up Adak West at about 0200 UT today and are receiving great data. I want to thank all of the MSI partners for their contributions to making this build a success. All went smoothly and we had a great time…no seriously despite horizontal rain for a good part of the time we had fun.'

Congratulations to Bill and the entire MSI build team!

View 'First Light' and Adak Island Photos Here!!!

Aug. 22nd Update:

The final hours at the site were spent going over a few leftover items on the 'To-Do' list. What could be done during this trip was finished off and some discussion with Randy Ou on things to look out for in the coming months. Before leaving the site, some quick measurements were made on the interferometer phasing cards. Here it seems as though some more work will need to be done in order to get the interferometer arrays at Fort Hays fully operational. However, upon leaving the site, all 32 transmitters were firing at full power.

*********

Following the restoration of the internet connection to the Blackstone site on the 6th of August, it was observed that the radar was not operating very well. The radar was not seeing any returns on most of the beams and only noise on some of the beams. So, a trip was made on August 8th by RF Engineer Kevin Sterne and graduate student Neeraj Pramodkumar.

From 8am Thursday July 5th to 2am Saturday July 7th (EDT) the clear frequency search functionality was disabled on three SuperDARN radars. The purpose of this fixed frequency experiment was to allow Bright Zheng, a local high school student, to listen for the radar transmit pulses using a shortwave amateur radio.

On Friday July 6th at 12:32pm (EDT) Bright was able to hear pulses transmitted by the Fort Hays East and Blackstone radars over a range of about 20 kHz.

Kevin Sterne's poster from the SD Workshop which highlights the various states of radar control electronics used by SuperDARN groups is posted in the SD 2012 Docs gallery or at:

http://vt.superdarn.org/tiki-download_file.php?fileId=986

A trip was made to the Blackstone radar on July 23rd to investigate a long-term internet connection outage as well as make modifications to the receive path. One of these experiments included a change to the mixing and frequencies along the receive path.

A new hdw.dat file is available for the Blackstone radar to reflect changes in the radar control electronics. The new electronics were installed at the site in late September so make sure you have the updated file.

The new hdw.dat.bks file can be found at:

http://sd-work5.ece.vt.edu/hdw/hdw.dat.bks.txt

A few Southern Hemisphere radars were tested out for the validity of the data as well as verifying that our plotting abilities in Southern Hemisphere are correct. As seen to the right, we focused on McMurdo and Zhongshan and showed an overlay of a field of view scan from each radar. Each of these radars are a bit different as they have beam numbers opposite of each of the other southern hemisphere radars.

In the fallout of the special time mode run in Jan. 2012, a question arose about the bandwidth of the 13 baud pcodescan mode that was the basis of the special mode. Concern was raised by Ray Greenwald that the bandwidth of the pulses was wider than our licensed spectrum. Having an available test rig to test and measure the spectrum of the pulses, Bill Bristow took to providing details on how the 13baud phase coded signal was within the licensed spectrum. He measured that the spectrum of the signal is about 40 kHz.
Below is an e-mail chain on this discussion, starting with Ray’s initial concerns, followed by Bill’s calculations and measurements, followed by Ray’s rebuttal to these measurements.

An experiment on HF propagation conducted between the Fort Hays radar site and a transponder located near Fort McPherson in the Northwest Territories of Canada occurred during the week of Feb. 13th to 17th. The transponder retransmits the signal with a certain amount of delay and frequency shift. Its believed that the re-transmitted signal showed up during a grayline propagation mode during the morning of Feb. 14 as seen in the scan plot to the left.

Summary


On Oct. 18, 2011, University of Alaska – Fairbanks P.I. Bill Bristow passed along a request from former SuperDARNer Todd Parris. After some discussion, the special time was granted for the SuperDARN radars to be included in Todd Parris’ experiment during January 2012. The control program necessary for this special time was developed by Todd and tested and tweaked by Kevin Sterne for the older QNX4 style radars. The control program for the newer QNX6 style radar was also developed by Todd, but not as extensively tested until the weeks before the scheduled special time. During the special time, the older QNX4 style radars provided data that was quickly and easily visualized. However, the QNX6 style radars’ data was not as easily visualized and processed in real-time. Some changes to software at the Virginia Tech lab led to the processing and visualizing of this data which is seen to the right.

In the weeks after the special time, much has been debated about the process of developing a new control program and requesting special time on a SuperDARN radar. Also, several ongoing discussions have occurred on the scientific merits of the data from the special mode as well as problems encountered during the special time.

Summary

On the morning of Jan. 25th, it was observed on VT’s tenplot, a sample of which is shown here, that the velocity sign of the Blackstone radar was incorrect. On this day, the issue was confused because the events in the early part of the day were observed as having the correct velocity sign on the real-time display. This issue was resolved when it was found that DaViT and the real-time display were using different velocity signs. This issue was discovered on Jan. 25 but not fixed until Jan. 31. On that day it was found that the velocity sign of the hdw.dat.bks file after the software reinstallation on Jan. 17 needed to be reversed from its previous value. The new value of velocity sign after the software reinstall needed to be +1. The hdw.dat.bks file on DaViT, the real-time display and at the radar have been updated to reflect this and other changes that were made in diagnosing the problem.

As identified by the P.I. for the Christmas Valley radar, Simon Shepherd, data for these radars prior to Dec. 2, 2010 was collected during the testing and setup of the radar. Because the radar was not fully operational prior to this date, the data should be erased and has been done so on our database.

A new control program generated by ex-SuperDARNer Todd Parris was tested at the Blackstone site on Dec. 20th. SuperDARN engineer Kevin Sterne assisted in the implementation of the new control program, pcpscan (CPID 9211). Some initial results of the new program can be seen in the picture.

Great news! With the latest trip to the site this week (Oct. 26th) the electronics at the Blackstone site are fully functioning! Along with the restoration of the internet connection, normal operations have resumed for this site as it was before the Univ. of Leicester electronics were packed up and shipped out of the country this past July.

A few changes to the new electronics can be observed on the Real-Time Data display, found in the left bar of the website. Of these changes, the radar's boresite is now at -40 degrees, the beam separation is 3.24 degrees, and the radar is now running with 24 beams.

Update 10/11/11:


Upon a return trip to the site on Oct. 4th, we were able to restore regular operation to the Blackstone radar!!! However, there are still some issues that need to be resolved, such as an internet connection to the site. On our "move-in" trip in late September, we found that our wireless internet hop was not working. We've since ordered parts and hope to install a new wireless system in the next week or so. We've also done some initial data analysis and notice that we have a few other things to work on to finalize the installation of the new electronics.