Interesting...I would like to know if you Westerners notice any differences.?ÿ
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@gschrock
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N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY
DOD has scheduled testing of GPS
https://www.navcen.uscg.gov/pdf/gps/gpsnotices/GPS_Interference.pdf
Company attempting to use spectrum close to GPS range
http://www.southgatearc.org/news/2018/january/gps-lobby-seeks-block-on-use-of-nearby-spectrum.htm
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But that being said..... tests at facilities like White Sands could be much more intense... but still (until I hear otherwise) there is care taken in seeking to not disrupt critical civilian activities in surrounding areas.
Per Wiki: "The Woodbridge site was closed in the 1990s, after the Army decided to stop electromagnetic pulse testing there. In 1989, the commander of the HDL said that the decision to stop this testing was mainly based on the Army's need to perform more powerful testing, something not appropriate for the thickly settled neighborhood around the site."
https://en.wikipedia.org/wiki/Harry_Diamond_Laboratories
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My father ran some of the above mentioned EMP tests, told me they fried a lot of civilian electronics in the nearby residential areas?ÿ ??ÿ
We have some snooper troopers running amok across our area that can drive by and we will lose connection to everything you are connected to wireless and the TV screen will go dark until they have gone over the hill.
They are not nearby long enough to knock out a GPS unit off. It will leave a blank in the data download timeline.
They have one of those smart cell phone signal grabbers that they are not supposed to be playing with too.
I once had a cell phone killer until it became unlawful. Got it because helpers could not stay off the phone long enough to finish a job.
I've even put in their gobag and tell them it was a backup if their radio went out.?ÿ
A week or so ago my R10 on the Utah VRS was really?ÿ not working so well. Slow to get a good solutions, poor precisions, even in wide open sky areas.?ÿ Not preforming normally for sure.?ÿ I have no idea what the problem was or is, just hope it goes away.
I usually work double redunantcy with two L1 base stations for static sessions.
On occasion one base unit that is located along some highway will stop collecting data because it will timeout with no signal from satellites.
I know one disturbance was due to a thunder cell passing thru the neighborhood blocking the sky.
Other times it happened with a clear blue sky and the other unit recording 8+ satellites.
It was not the same unit affected each time.
I had a unit not collect any data at all. When I arrived to pack away for the day it had been messed with and was perfectly setup 0.15ft away from the 1/2in rebar I set on that morning.
I am still not ruling out that someone stopped and was checking out the equipment and caused the disruption.?ÿ If that is the case they are going out of their way and climbing up a steep hill or at least 200+ft from the pavement to get to the base.
The Video from a night time launching of planes during the Red Flag War Drills is always cool if your stuck at out in a field getting hammered by interference.?ÿ ?ÿ Headphones recommended?ÿ?ÿ https://www.zerohedge.com/news/2018-01-26/usaf-begins-massive-gps-blackouts-western-us-during-largest-ever-air-war-drill
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Joel
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Always pays to be cautious (but also to wonder about how much sensationalism there is in?ÿ some articles like that).?ÿ
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Agreed, HOWEVER, a ton of cycle slips last year east of Chehalis, WA made me think I might of had some bad effects from the testing at that time at Bangor Base, we were within the cone of influence, base receiver was wide open, a lot of birds could of landed on the antenna roost I suppose? Anyway always good to be aware of potential issues and if you can reschedule GNSS operations during the posted testing windows it probably is good policy.
SHG
One way to see what is (or is not) happening around said test range is to look at observed GPS data from CORS and PBO stations:
https://www.unavco.org/instrumentation/networks/status/pbo
There are time series, TEQC reports, and more from before and during the subject period. Or you can download data and process/analyze it yourself. I've been in touch with the DHS Navcen?ÿ (USCG) www.navcen.uscg.gov (who track GPS issue reports) and they have not heard anything scary yet.
Always pays to be cautious (but also to wonder about how much sensationalism there is in?ÿ some articles like that).?ÿ
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I hadn't looked at the PBO stations for awhile.?ÿ Looks like the data is available in real time 1 Hz.?ÿ Could this data be integrated into the Utah VRS??ÿ There are three PBO stations around me that would probably improve my vertical quite a bit.?ÿ I've been to two of them.
One way to see what is (or is not) happening around said test range is to look at observed GPS data from CORS and PBO stations:
https://www.unavco.org/instrumentation/networks/status/pbo
There are time series, TEQC reports, and more from before and during the subject period. Or you can download data and process/analyze it yourself. I've been in touch with the DHS Navcen?ÿ (USCG) www.navcen.uscg.gov (who track GPS issue reports) and they have not heard anything scary yet.
Always pays to be cautious (but also to wonder about how much sensationalism there is in?ÿ some articles like that).?ÿ
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I hadn't looked at the PBO stations for awhile.?ÿ Looks like the data is available in real time 1 Hz.?ÿ Could this data be integrated into the Utah VRS??ÿ There are three PBO stations around me that would probably improve my vertical quite a bit.?ÿ I've been to two of them.
Back when a lot of the PBO array was established, the charter was pretty much science-only, GPS only, and only post-processing static data. But over time some forward thinking folks in Unavco (with a lot of pushing from the outside, including RTN) began their streaming service (as the scientific community showed more interest in real-time studies), and have partnered with local entities to upgrade stations to new gear that can observe multi-constellations. Our RTN did not initially include many PBO sites as (in the early days) they were GPS only with no live streams. Things changed; I have since sponsored upgrades to a number of PBO's, set up redundant comms, and have them in solution.
There are quirks and considerations for each site (some may be satcomm with high latency, and we cannot get the full raw observations we'd prefer, usually RTCM 3 or Binex -but those are usable), and I am pretty sure the Utah RTN has looked into them, but it might be worth giving Sean a call and mention the site you have in mind.
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This station is quite remote, probably using satcomm.?ÿ Not to far from me.?ÿ It got burnt in the Wood Hollow fire in 2012.
I have worked at Nellis (during a Red Flag exercise) and China Lake with no problems.?ÿ
I had serious problems at Eglin in FL with navigation GPS (Garmin), but no problems with survey grade. I was driving along on the south side of the base and my ground track was way out in the ocean. I believe they were jamming or spoofing.?ÿ
This all should make us think...the reason they are doing this is to see what would happen if GPS takes a dive. I believe if we ever get into a tiff with China the first thing they would do is try to take out the GPS system by trying to destroy satellites.?ÿWe are SO dependent on GPS for survey nowadays, NGS has already made the decision to go GPS/GNSS only. What happens if the system is disabled? How many surveyors out there could get an accurate azimuth without GPS?
And another huge issue is that our whole communications infrastructure is now digital, and extremely dependent on GPS for time synchronization. I reckon the whole cell network would be non functional or at least severely degraded. . If they would not have mothballed eLoran they could possibly use that for timing, but I think that is not an option now.?ÿ?ÿ
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P110 station data indicates it has this receiver:
Says it tracks all GNSS systems.
I see from the maintenance records that ti has a cell modem, but I'm not seeing it on the streaming caster. I'll check with Unavco on that. Looks like it could be a good station for and RTN, and a noise model should be available later this month. The PolaRx5 makes a great RTN base; I'm deploying a bunch this summer.
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About what would the PolaRx5 receiver cost?
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?ÿI don't doubt that people get effected by mil or other RF sources (I have been able to capture altimeter radar effects with spectrum analyzers and static files).?ÿ
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You're also lucky enough to have every Navy EA-18G Growler electronic warfare squadron based at NAS Whidbey Island.?ÿ Who knows what buttons get accidentally pushed while the pilots are busy drawing contrail genitalia over the Washington skies.?ÿ ? ?ÿ ?ÿ
Not related to the current exercises, but along about 2002 I was working on Bangor Naval?ÿBase?ÿfor a few weeks, UHF RTK comms did not work, had a 35W PacCrest radio running at 35W and line of sight less than 2000 feet, nothing at the rover. When I mentioned it to my POC, I got the we know, but aren't telling you look. I had an instance many years ago (1994 maybe) where a trooper would blast all my satellites off the air every time he keyed his radio parked about 100 feet from my setup during a traffic stop, another time the flight crew had a bad radio in the stack, every time they tried to do air to ground comms with me, lost all satellites on the survey grade receiver on board the aircraft and on and on. I recall during the 1998 HARN re-obs campaign here in Oregon, we were specifically instructed to NOT have any radio comms within 300' feet IIRC including cell phones.
Recently on the 20th of January, on a flight in California, our flight crew had all kinds of weirdness with the Track-Air flight management system for the aerial camera, this was observed in real time in the aircraft and they re-flew a couple lines just to be sure we had coverage in the correct location, we don't know the reason, but the site is about 60 miles north of Beale AFB, coincidence?
Point is, lots of RF can and does interfere with GNSS signals and one should always be aware of that when strange things happen. I suspect receivers are getting better at out of band interference rejection, but a strong signal can overpower the front end of any receiver. I was up on a local mountain recently for some Ham radio activity where there are about 50 transmitters of all types and the two way mobile radio in my truck was picking up interference from a law enforcement repeater, a bit gabbled, but definitely overpowering the radio receiver.
SHG
With the Trimble 4000 SSE & SSI units that I ran from about 98-2010 I learned not to answer my phone or key the Motorola VHF walkie-talkies within a couple hundred feet of the receiver.?ÿ Doing so would always cause a reduction in the number of birds tracked if not a complete loss until the transmission ended and they could reacquire lock.?ÿ ?ÿI also learned to spot microwave antennas when I was working on communication sites.?ÿ Setting a receiver within a few degrees of a microwave antenna path will guarantee zero satellites all afternoon.?ÿ ?ÿ
As you can see from the aerial below, I didn't have much room to work.?ÿ I had maximized my sky-view when we were setting control with a total station and given no thought to the towers or antennas.?ÿ I had made the two hour round trip drive to the control point near Cherokee, NC to drop my co-worker with instructions to start the base at a certain time and run until the batteries gave out.?ÿ Back on site I set one unit and fired it up and left it searching for sv's while I set up the second receiver.?ÿ Once I got the second receiver logging data I headed to the first one to start it logging and found it tracking zero sv's.?ÿ I did a quick check of cables etc. and decided it must be something else.?ÿ I'd heard that microwaves could cause issues.....that was the day I discovered what microwave antennas look like.?ÿ I had set up about 30-50 feet below and almost directly inline with one of the huge drum shaped microwave antennas.?ÿ With the clock ticking, I picked up the tripod and receiver and moved offline until I could get sv's and set a new control point.?ÿ I ran about an hour session (praying that the base was still running), then had to locate the new point with the total station.?ÿ Did I mention that it had started raining??ÿ Fun times and lessons not soon forgotten.
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Cowee Bald, NC
Here's a view from the ground.?ÿ This was taken by a hiker in the past couple of years but it was nearly as infested with towers and antennas when I was there in 98-99.
Early 90's, single frequency receivers (Trimble 4000SSE, which were more susceptible to interference). No HARN, no CORS. I was doing a control job on St Thomas, USVI. At the time there was ONE second order triangulation station on St Thomas, and a few third order stations. The station was on top of a pill box, and had a microwave antenna about 2 feet away. Setup on it. No data at all. Zero SVs. Microwave was killing it.?ÿ
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Had to do an eccentric, backsighted an offshore lighthouse.?ÿ
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Gavin, good points. On the mountain I mentioned where my VHF 136-172 Mhz two way radio was overwhelmed, my HF rig operated just fine on 20m (14 Mhz) where I made contacts into the mid west from Oregon on under 15w of RF power, so it does depend and you just never know, main thing is to be aware of possible issues.
SHG