Jump to content

Gps Jamming Trials


Followers 0

Recommended Posts

There are around 160 caches within 38nm of those coordinates (assuming I have plotted them correctly :ph34r: )!

 

Even thought the effect only works on a line of sight basis (so at ground level you should be OK providing theres a hill in the way...) it must effect some of them.

 

I certainly dont fancy getting lost in the brecon beacons that week! :rolleyes:

 

Joking appart, it does seem rather surprising that they are choosing to block GPS signals to an area much loved by hill walkers (including groups young people on D of E awards expeditions) during the school holidays.

Link to comment
But it is the time of year when inclement weather is least likely to leave people stranded

 

True :ph34r:

 

Hadnt thought of that, and of course anyone out on the hills knows how to use a map and compass..... :rolleyes:

 

Out of interest, would they turn off the jamming signals in the case of a mountain /helicopter rescue in poor visibility?

Link to comment
Areas with a clear line of site to the transmitter positions

Which is where, precisely? Does anyone know of / have access to a mapping utility which can take as input a location, compare it to a relief map of the UK, and output a shapefile containing the areas which have a line of site to that location?

Link to comment
Do I understand correctly that for 3 periods of 4-5 days, any aircraft within 38 nautical miles will be without GPS navigational ability?

 

Isn't that a bit irresponsible?

Not at all.

 

Any aircraft flying under Visual Flight Rules (VFR) must, by law, be navigating by traditional navigational methods, including map and compass work.

 

Any aircraft flying under Instrument Flight Rules (IFR) must, also by law, have a suite of terrestrial radio navaid receivers including VOR, DME and ADF.

 

GPS is an add-on luxury, not a normal part of aeronautical navigation practice.

 

Any pilot who gets him/herself into a situation whereby loss of GPS entalils loss of positional awareness, whether the GPS signal loss is notammed or not, is liable to prosecution for reckless flying.

Link to comment
Out of interest, would they turn off the jamming signals in the case of a mountain /helicopter rescue in poor visibility?

They might, but helicopters flying at low level in poor visibility seldom depend upon GPS to know where they are. ASR helicopters navigate visually with at least two crew members looking out of the window.

 

Royal Air Force and Royal Navy rescue helicopters are not fitted with GPS.

Link to comment
Areas with a clear line of site to the transmitter positions

Which is where, precisely?

52° 01.167'N 3° 36.683'W ±3nm

 

To block the jamming signal, simply input that location as a waypoint and look at the bearing to the location; then simply place your hand beside the GPSr antenna between you and the direction of the location of the jammer.

 

The water in your hand will block the jamming signal very effectively, just as it will block any GPS signal.

Link to comment
Royal Air Force and Royal Navy rescue helicopters are not fitted with GPS.

Mountain rescuers, on the other hand, often are fitted with GPS... but would be far too worried about the stick they'd receive in the pub (once a week for the next 25 years!) to let themselves get lost in the fog :rolleyes:

Link to comment

You must also remember that GPS is a military owned system that we are allowed to use. The fact that it belongs to the military means that they need to do tests, our military would want to use it in a war but not allow the enemy to use it, you need to carry out tests to find out how that can be achieved. I think we should all be gratefull that we are allowed to use it at all, and accept that the military can switch it on and off when they please.

Link to comment
Mountain rescuers, on the other hand, often are fitted with GPS...

I believe that anyone who is fitted with a GPS for mountain rescue, may well be fitted with it at their own expense (Willing to be corrected only by a member of a mountain rescue team).

 

I would also be surprised if a member of mountain rescue used the GPS for their primary navigation. I was speaking to a member of Galloway Mountain rescue only a week ago, and he asked me how to use a GPS for navigation. He said he owned one but prefered the map and compass.

Link to comment
To block the jamming signal, simply input that location as a waypoint and look at the bearing to the location; then simply place your hand beside the GPSr antenna between you and the direction of the location of the jammer.

These signals are strong enough to disrupt GPS receivers as far as 70 - 350km away! Inverse square law being what it is, if I'm 30km away with direct line of site to the transmitter, won't there be such a high local signal strength that reflected signals from any nearby tree, rock, house or whatever will be just as effective at jamming reception as the direct signal?

 

I was hoping to find the areas with line of site to Sennnybridge and automatically add a warning box to any caches in those areas (when viewed via G:UK).

Link to comment
You must also remember that GPS is a military owned system that we are allowed to use. The fact that it belongs to the military means that they need to do tests, our military would want to use it in a war but not allow the enemy to use it.

A very good reason for a civil system such as Galileo to be established.

 

I think we should all be gratefull that we are allowed to use it at all, and accept that the military can switch it on and off when they please.

 

Unfortunately the military will disrupt the civil Galileo system as easily as they disrupt civil reception of the military versions of GPS which we call Glonass and NavStar.

Link to comment
won't there be such a high local signal strength that reflected signals from any nearby tree, rock, house or whatever will be just as effective at jamming reception as the direct signal?

Yes.

 

Just curve the palm of your hand -- or read a map!!

 

Alternatively, do what the spirit of the AIC suggests, which is to plan your use of GPS around a very temporary and very well promulgated loss of SatNav service in a highly localised area.

Link to comment
I would also be surprised if a member of mountain rescue used the GPS for their primary navigation.

You certainly get sarcastic comments if you so much as power one up during a training exercise! :rolleyes: But on a real, "known location" job, on a misty, featureless moor, you're likely to find someone striding out at the front following the GPS arrow, with someone bringing up the rear with map and compass, providing a sanity check.

 

I guess about 1 in 4 of my team carry their own units. I don't know of any Mountain Rescue teams which provide GPSrs as part of team kit. However SARDA recently bought a number of MemoryMap equipped IPAQs and sold them to search dog handlers at a very good price.

 

Searches are where GPSs come into their own. On a search, many sections of maybe 4 people each are given small areas to search and sent out. When sections return, the controllers must debrief the section leader to find out exactly where they did / did not look within that area. Having a GPS record of exactly what route you took can really help. And now that search controllers have MemoryMap, you can just plug your Garmin into their laptop and your route is immediately overlayed on a 1:25K map, along with the routes taken by all the other sections. Very useful!

Link to comment
You must also remember that GPS is a military owned system that we are allowed to use. The fact that it belongs to the military means that they need to do tests, our military would want to use it in a war but not allow the enemy to use it.

A very good reason for a civil system such as Galileo to be established.

 

I think we should all be gratefull that we are allowed to use it at all, and accept that the military can switch it on and off when they please.

 

Unfortunately the military will disrupt the civil Galileo system as easily as they disrupt civil reception of the military versions of GPS which we call Glonass and NavStar.

We would need jamming/disrupting technology even for a civil system, it would be a joke if a hostile force could use a nations civil or even military system against themselves, besides I doubt that a civil system would get put up if there wasnt an option to scramble the signal for wither military or comercial reasons.

 

It would be interesting to have an idea just how long satalite based technology would last in the event of an international conflict, I doubt it would be long at all.

 

This system they are developing looks to be more of an area exclusion system, I would envisage it being set up as part of a high security perimeter to disrupt GPS guided attacks... think the kinda security we saw in scotland at the G8 summit

Link to comment

GPS jammers generally don't work against airborne munitions as they are within the jammer's field of inluence for too short a time to throw them off

 

Also, most PGMs don't rely exclusively on GPS, they usually have at least one alternative system, like an inertial nav system

 

These area systems are intended to stop recce platforms or people from getting an accurate position [and call in the PGMs!]

Link to comment

Your confusing in flight control with targetting, if you cant aquire a position of a target, then you cant remotely attack it.

 

The thing is, there are always alternatives, and defence normally about limiting them with a package of measures, rearely is there a single measure that is a solveall solution.

Link to comment

And recce works without GPS. GPS simplifies things - but would you rely on GPS to recce for your munitions when it can be easily blocked, scrambled etc?

 

I have had GPS tell me I am six miles from where I am (I was near Old Sarum at the time). Positioning from an old lump of iron set in the ground was more accurate!

Link to comment

Thats the point, being able to scramble GPS removes it from being a viable tool, if it wasnt possible to scramble it, then it would be a viable tool.

 

We have all had times when it goes on the fritz, but, being experienced users we learn to recognise the problems and accomodate for them

Link to comment

FAC is all about knowing where you are, and knowing where something else it. FAC as a discipline was invented long before GPS and I have no doubt that competent FACs would use GPS as only one tool of the job. If GPS ever were to replace FAC you would not need FACs as any Geocacher could calculate the necessary projection.

Link to comment
GPS jammers generally don't work against airborne munitions as they are within the jammer's field of influence for too short a time to throw them off

Military aircraft use the anti-spoofing capabilities of GPS and anyway are not very prone to ground-based jamming because the aircraft's GPS antenna is on top of the aircraft. That goes for both manned and unmanned aircraft

 

JDAM GPS guidance tailkits are designed to 'look' upward, not downward, and are therefore quite resistant to ground-based jammers.

 

Anyway, there are plenty of missile systems such as HAARM which make short work of any jammer's transmitter!

 

During America's most recent bombing war against Iraq the defenders tried unsuccessfully to use cheapo Russian jammers to foil the aggressor's use of GPS and failed spectacularly.

 

It turns out that jamming GPS is actually quite difficult. This is one of several reasons why QinetiQ conducts so many jamming trials whic are the subject of these quite frequent pink AICs.

Link to comment
If GPS ever were to replace FAC you would not need FACs as any Geocacher could calculate the necessary projection.

US FAC use GPS in conjunction with laser designators. AFAIK they do not receive the advanced land nav training that the Brit SF do.

 

During the recent attack against Afghanistan at least one US FAC killed himself by transmitting his own GPS co-ordinates by mistake! :rolleyes:

 

Our own SF learn how to augment a "shiny thing" with a sound knowledge of land surveying techniques. All FACs and usually at least one member of each 4 or 6 man patrol has been trained up to first year university level in high precision land navigation.

Link to comment
FAC is all about knowing where you are, and knowing where something else it. FAC as a discipline was invented long before GPS and I have no doubt that competent FACs would use GPS as only one tool of the job. If GPS ever were to replace FAC you would not need FACs as any Geocacher could calculate the necessary projection.

Again it boils down to removing the usefullness of the tools you can, GPS makes the difference between a local resistance/espionage cell/fanatics, of untrained individuals doing the job, or a highly trained guy who can do it with a map and compas.

Link to comment
GPS makes the difference between a local resistance/espionage cell/fanatics, of untrained individuals doing the job, or a highly trained guy who can do it with a map and compass.

 

I'd never thought of geocachers in quite that way, but I suppose you are right. <_<

 

Just teasing! :o

 

More seriously, what actually happens when the Americans start one of their horribly frequent wars against a small country is that they don't withdraw NavStar GPS service from the "theater". Actually, they tend to make the system even more user friendly because the great majority of their troops are quite low grade and only join the military because for many families it is the only way to afford some kind of basic college education. Their navigational skills tend to be limited to following single-arrow road signs and some of them are barely even able to do that.

 

In a challenging environment such as a desert, without a sound knowledge of how to 'read' the landscape and a solid knowledge of how to navigate, such low grade troops desperately need something as simple to use as GPS.

Link to comment
I would also be surprised if a member of mountain rescue used the GPS for their primary navigation.

You certainly get sarcastic comments if you so much as power one up during a training exercise! <_< But on a real, "known location" job, on a misty, featureless moor, you're likely to find someone striding out at the front following the GPS arrow, with someone bringing up the rear with map and compass, providing a sanity check.

 

I guess about 1 in 4 of my team carry their own units. I don't know of any Mountain Rescue teams which provide GPSrs as part of team kit. However SARDA recently bought a number of MemoryMap equipped IPAQs and sold them to search dog handlers at a very good price.

 

Searches are where GPSs come into their own. On a search, many sections of maybe 4 people each are given small areas to search and sent out. When sections return, the controllers must debrief the section leader to find out exactly where they did / did not look within that area. Having a GPS record of exactly what route you took can really help. And now that search controllers have MemoryMap, you can just plug your Garmin into their laptop and your route is immediately overlayed on a 1:25K map, along with the routes taken by all the other sections. Very useful!

I really can't argue with that, a well put explanation on how the GPS comes into it's own for mountain rescue. It's good to see that someone still follows up with map & compass though, because I think you can't beat it.

Link to comment
It's good to see that someone still follows up with map & compass though, because I think you can't beat it.

Hear hear!

 

I well recall, with some chagrin:( , spending about an hour failing to find a riverside cache in Embra. My excuse was that the co-ordinates were duff (they were!), but the cache was subsequently found by a hunter of the beaked creature who used traditional map & compass and a good dollop of common sense to find the cache before his GPSr had been delivered by Santa. <_<

 

GPS is a brilliant augmentation for good navigation technique, but ought not to be regarded as a replacement for navigational skills.

 

On the few(?!) occasions when I have made a complete Horlicks of navigating, I have invariably done so because I have failed to apply the basics of nav.

 

Cheers, The Forester

Link to comment
I would also be surprised if a member of mountain rescue used the GPS for their primary navigation.

You certainly get sarcastic comments if you so much as power one up during a training exercise! <_< But on a real, "known location" job, on a misty, featureless moor, you're likely to find someone striding out at the front following the GPS arrow, with someone bringing up the rear with map and compass, providing a sanity check.

 

I guess about 1 in 4 of my team carry their own units. I don't know of any Mountain Rescue teams which provide GPSrs as part of team kit. However SARDA recently bought a number of MemoryMap equipped IPAQs and sold them to search dog handlers at a very good price.

 

Searches are where GPSs come into their own. On a search, many sections of maybe 4 people each are given small areas to search and sent out. When sections return, the controllers must debrief the section leader to find out exactly where they did / did not look within that area. Having a GPS record of exactly what route you took can really help. And now that search controllers have MemoryMap, you can just plug your Garmin into their laptop and your route is immediately overlayed on a 1:25K map, along with the routes taken by all the other sections. Very useful!

Every member of the team I am in is issued with GPS as team kit. We specifically train with them and they have proved invaluable in poor conditions. We have rescued at least one party who gave us a correct 10 figure OSGB grid reference. However, everyone is expected to be able to use map and compass as their primary navigational aid. Batteries failing, screens going wonky in extreme weather etc....

Other teams in Scotland also use GPS extensively and have positions of well known points preloaded into their units - tops of prominent winter climbs for example which are notoriously difficult to find at night in a white out.

I can only agree with Teasel about the download of routes taken once back at base. this readily identifies areas that have been missed for secondary searches.

I also understand that in one particularily gruesome search, (details withheld!) GPS info on key forensic locations was used to build a court case.

Link to comment

It's not only Scottish MRTs which use GPS.

 

A while before SA was removed indefinitely, an MRT in Colorado was having difficulty in navigating some extremely steep terrain in whiteout conditions around a mountain called Craig's Peak. They were under intense pressure to find the remains of an A-10 pilot called Craig Button who had absconded with his jet and symbolically crashed into the mountain of his name.

 

There was considerable embarrassment within the USAF that an unstealthy aircaft could quite simply vanish, so every effort was made to try to find the wreckage.

 

An informal arrangement was made between the MRT and the controllers of GPS in Cheyenne Mountain to switch off SA temporarily so that the MRT guys in the field could get good fixes for a few hours.

 

This SA-removal incident was gleefully seized upon by those of us who had been campaigning for years to have SA permanently abolished. It was a brilliant example of the advantages of full accuracy GPS being available, without restrictions, to the worldwide community.

Link to comment
Royal Air Force and Royal Navy rescue helicopters are not fitted with GPS.

This is not true. All UK SAR helicopters are fitted with GPS systems. RAF SeaKings have an integrated fit - their GPS operates alongside other navigational systems. RN SeaKings have standalone GPS units.

These rescue helicopters have had GPS fitted for some years now.

Link to comment

Thanks for the correction. My info on SAR helos is obviously out of date.

 

Last time I worked with them, even the Nimrods at Kinloss did not have an internal fit of GPS. Two of the nav guys had their own private units with a suction-cup attachment to hold the antenna onto one of the windows!

At the time, neither the Lossie nor Gannet SKs had GPS fitted.

 

Always good to see them catching up with the 21st Century!

 

Cheers, The Forester

Link to comment

Looks like my mapping will be well and truly seen to for two weeks in the brecon area. This will affect not only geocachers. I use a gps for mapping for work as well as geocaching. Ok, I can use a map, as I have for years, but come on, lets be honest, having mapping in the cab makes life real easy.......

Link to comment
Out of interest, would they turn off the jamming signals in the case of a mountain /helicopter rescue in poor visibility?

They might, but helicopters flying at low level in poor visibility seldom depend upon GPS to know where they are. ASR helicopters navigate visually with at least two crew members looking out of the window.

 

Royal Air Force and Royal Navy rescue helicopters are not fitted with GPS.

Just to correct the all knowledgable 'Forrester', RAF and Navy Search and Rescue helicopters DO have Gps as do the Coastguard.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Followers 0
×
×
  • Create New...