Have you had problems with GPS??
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Have you had problems with GPS??
Any help with this would be most appreciated.
Do you use GPS to navigate and have you experienced any problems? – If so I would be most interested in hearing your thoughts on the questions below no matter how small or insignificant the information. There has been little published about actual in-flight experiences by GA pilots, it will be interesting to hear your views.
1) Have you experienced any technical problems with GPS navigation in light aircraft? Do you know the reason for the problem?
2) Have you experienced any human factor problems with GPS navigation? E.g. – due to: over reliance, lack of formal training, lack of integration of information with traditional navigation systems.
3) Have you used certified GPS installations to navigate under IFR? Do you have any comments on this use of GPS?
4) Do you have any thought on the future of GPS / GNSS within general aviation – ie GPS certified precision approach introduction, LAAS / WAAS etc?
All replies will be treated anonymously and this information will not be passed on to any third parties.
Many thanks in anticipation
-Dan Nutt
_________________________________________________
My final year project (Aeronautical Engineering Degree - BEng) is entitled - Investigation of Global Navigation Satellite System Application to General Aviation for Improved Navigation.
I am investigating:-
What are the specific problems with the use of GNSS (Global Navigation Satellite Systems) within GA navigation and what factors are causing the current problems
How can new developments in both user (GNSS receiver units and associated equipment) and service provider (GNSS satellite networks and ground based support equipment) technologies as well as future training regimes be made use of to:
- Improve ease and accuracy of navigation
- Improve robustness and reliability of navigation systems
The objectives of this project are as follows
- To make recommendations for GNSS user installations within the GA field resulting in a series of conceptual designs / ideas. This should cover both GNSS receiver unit design and its integration with associated systems. Consideration should be given to compatibility with legacy designs / equipment and the allocation of function between the pilot and the system.
- To establish pilot training requirements with respect to the use of GNSS.
- To establish a suitable service provider GNSS system / upgrade for use within European Airspace.
The desired outcome is to prompt discussion on the topic of GNSS application to GA navigation and to raise awareness within the flying community, the national / international authorities and the manufactures.
_________________________________________________
Do you use GPS to navigate and have you experienced any problems? – If so I would be most interested in hearing your thoughts on the questions below no matter how small or insignificant the information. There has been little published about actual in-flight experiences by GA pilots, it will be interesting to hear your views.
1) Have you experienced any technical problems with GPS navigation in light aircraft? Do you know the reason for the problem?
2) Have you experienced any human factor problems with GPS navigation? E.g. – due to: over reliance, lack of formal training, lack of integration of information with traditional navigation systems.
3) Have you used certified GPS installations to navigate under IFR? Do you have any comments on this use of GPS?
4) Do you have any thought on the future of GPS / GNSS within general aviation – ie GPS certified precision approach introduction, LAAS / WAAS etc?
All replies will be treated anonymously and this information will not be passed on to any third parties.
Many thanks in anticipation
-Dan Nutt
_________________________________________________
My final year project (Aeronautical Engineering Degree - BEng) is entitled - Investigation of Global Navigation Satellite System Application to General Aviation for Improved Navigation.
I am investigating:-
What are the specific problems with the use of GNSS (Global Navigation Satellite Systems) within GA navigation and what factors are causing the current problems
How can new developments in both user (GNSS receiver units and associated equipment) and service provider (GNSS satellite networks and ground based support equipment) technologies as well as future training regimes be made use of to:
- Improve ease and accuracy of navigation
- Improve robustness and reliability of navigation systems
The objectives of this project are as follows
- To make recommendations for GNSS user installations within the GA field resulting in a series of conceptual designs / ideas. This should cover both GNSS receiver unit design and its integration with associated systems. Consideration should be given to compatibility with legacy designs / equipment and the allocation of function between the pilot and the system.
- To establish pilot training requirements with respect to the use of GNSS.
- To establish a suitable service provider GNSS system / upgrade for use within European Airspace.
The desired outcome is to prompt discussion on the topic of GNSS application to GA navigation and to raise awareness within the flying community, the national / international authorities and the manufactures.
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Hi Dan
In reply.......
1. Rarely do I seem to experience technical problems with my GPS. Very occasionally it tells me that it has "Poor Coverage" and that has only ever happened twice (both near Northampton strangely enough). Otherwise, it seems to work a treat. It is a Garmin unit and I think it's great. I used to have a Skyforce Skymap but found it very unreliable and the back-up from Skyforce was appauling.
2. No. I use the GPS very much as a back up to my Nav. I mainly concentrate on VOR's and NDB's but the GPS is great for giving leg times etc and cross checking the drift etc. Over water it is fantastic especially with nothing to visually cross ref with the track.
3. Not IMC ot IR qualified so cannot comment.
4. Was asked to a meeting in a hotel in Reading a few years ago to discuss the future of GPS in GA and the guy there was very interesting. He was talking about this very subject and felt that GPS would be the primary precision approach tool within 10 yrs. A lot of it went over my little head as I am pure a VFR bloke but it was interesting.
What I will say to finish is this.....
I feel that GPS has a lot more to offer than people give it credit for. Too many people seem to shove it to one side because they say it is not "reliable" or it isn't "safe".
The methods by which we currently navigate in standard form are antiquated (with a capital A). Why is GPS seen to be the devil that it isn't? Better training is certainly required and perhaps a licence (like the radio licence) should be encouraged so that people's GPS's are up to date with current airspace, frequencies etc.
That's my views. If anyone wants to shoot me down then please accept that I am giving Dan my personal views for his studies. I have not just supplied the flamers with a kilo of firelighters and if you do decide to ignite on me then don't expect a reaction!!!
reynoldsno1--------nice one mate. Nothing like being helpful. Have you studied this subject in detail yourself? If so it might be nice to give the guy some feedback of your research.
In reply.......
1. Rarely do I seem to experience technical problems with my GPS. Very occasionally it tells me that it has "Poor Coverage" and that has only ever happened twice (both near Northampton strangely enough). Otherwise, it seems to work a treat. It is a Garmin unit and I think it's great. I used to have a Skyforce Skymap but found it very unreliable and the back-up from Skyforce was appauling.
2. No. I use the GPS very much as a back up to my Nav. I mainly concentrate on VOR's and NDB's but the GPS is great for giving leg times etc and cross checking the drift etc. Over water it is fantastic especially with nothing to visually cross ref with the track.
3. Not IMC ot IR qualified so cannot comment.
4. Was asked to a meeting in a hotel in Reading a few years ago to discuss the future of GPS in GA and the guy there was very interesting. He was talking about this very subject and felt that GPS would be the primary precision approach tool within 10 yrs. A lot of it went over my little head as I am pure a VFR bloke but it was interesting.
What I will say to finish is this.....
I feel that GPS has a lot more to offer than people give it credit for. Too many people seem to shove it to one side because they say it is not "reliable" or it isn't "safe".
The methods by which we currently navigate in standard form are antiquated (with a capital A). Why is GPS seen to be the devil that it isn't? Better training is certainly required and perhaps a licence (like the radio licence) should be encouraged so that people's GPS's are up to date with current airspace, frequencies etc.
That's my views. If anyone wants to shoot me down then please accept that I am giving Dan my personal views for his studies. I have not just supplied the flamers with a kilo of firelighters and if you do decide to ignite on me then don't expect a reaction!!!
reynoldsno1--------nice one mate. Nothing like being helpful. Have you studied this subject in detail yourself? If so it might be nice to give the guy some feedback of your research.
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Monocock - Thanks for your response, I fully agree.
I think training is important - certainly if GPS is to develop - this links with the human factors issue, in my experience it is 10 times harder and takes 10 times as long to find that particular sub menu or option in the air than on the ground
There have been some interesting studies in Australia regarding Local Area Augmented GPS precision approaches - the results were very good
-Dan
I think training is important - certainly if GPS is to develop - this links with the human factors issue, in my experience it is 10 times harder and takes 10 times as long to find that particular sub menu or option in the air than on the ground
There have been some interesting studies in Australia regarding Local Area Augmented GPS precision approaches - the results were very good
-Dan
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Unfortunately this is inevitably going to be another GPS/anti-GPS debate - it's unavoidable because GPS cannot be integrated into the standard PPL (not enough hours as it is to do navigation properly, not enough money to fit GPS into flying school planes).
1) Have you experienced any technical problems with GPS navigation in light aircraft? Do you know the reason for the problem?
Never had any problems (300 hours with GPS)
2) Have you experienced any human factor problems with GPS navigation? E.g. – due to: over reliance, lack of formal training, lack of integration of information with traditional navigation systems.
Never had any problems. Been using GPS/VOR/DME/ADF concurrently, since day after the PPL skills test... Far easier, far more reliable, far more accurate than dead reckoning.
There is no formal training. Most instructors detest it, the CAA doesn't like it, the GA and CAA publications are improving but are still mostly negative about it.
3) Have you used certified GPS installations to navigate under IFR? Do you have any comments on this use of GPS?
Use it under IFR all the time, as described above. As does practically every IFR pilot. For people who fly "serious" journeys, and for owners of modern aircraft, the whole issue has become moot a long time ago.
4) Do you have any thought on the future of GPS / GNSS within general aviation – ie GPS certified precision approach introduction, LAAS / WAAS etc?
It will never make it into the PPL (unless GA as we know it sinks first, and somebody realises that the number of people interested in WW1 type navigation in WW2 aircraft is too small to sustain the traditional scene).
We might get US-style GPS approaches one day. It would be great for airfields without an IAP. It will need an awful lot of traditionalists to change their minds though...
1) Have you experienced any technical problems with GPS navigation in light aircraft? Do you know the reason for the problem?
Never had any problems (300 hours with GPS)
2) Have you experienced any human factor problems with GPS navigation? E.g. – due to: over reliance, lack of formal training, lack of integration of information with traditional navigation systems.
Never had any problems. Been using GPS/VOR/DME/ADF concurrently, since day after the PPL skills test... Far easier, far more reliable, far more accurate than dead reckoning.
There is no formal training. Most instructors detest it, the CAA doesn't like it, the GA and CAA publications are improving but are still mostly negative about it.
3) Have you used certified GPS installations to navigate under IFR? Do you have any comments on this use of GPS?
Use it under IFR all the time, as described above. As does practically every IFR pilot. For people who fly "serious" journeys, and for owners of modern aircraft, the whole issue has become moot a long time ago.
4) Do you have any thought on the future of GPS / GNSS within general aviation – ie GPS certified precision approach introduction, LAAS / WAAS etc?
It will never make it into the PPL (unless GA as we know it sinks first, and somebody realises that the number of people interested in WW1 type navigation in WW2 aircraft is too small to sustain the traditional scene).
We might get US-style GPS approaches one day. It would be great for airfields without an IAP. It will need an awful lot of traditionalists to change their minds though...
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Dan,
You should also contact/ look at the posting Chris Morshead has put on the On Track discussion site:
On Track
It is in the "Your Say" section and he seems to be doing a similar project to you.
You will also find the output of more lengthy discussions on the subject
All the best
D&O
You should also contact/ look at the posting Chris Morshead has put on the On Track discussion site:
On Track
It is in the "Your Say" section and he seems to be doing a similar project to you.
You will also find the output of more lengthy discussions on the subject
All the best
D&O
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Thanks for all your comments
Does anyone have any experience of Local Oscillators in radio installations blanking GPS signals?
From the information I have it seems that is only a problem on handhelds with attached aerials?
Any thoughts - particularly on VHF channels that this occurs on and radio installations that cause it?
Help much appreciated
-Dan
Does anyone have any experience of Local Oscillators in radio installations blanking GPS signals?
From the information I have it seems that is only a problem on handhelds with attached aerials?
Any thoughts - particularly on VHF channels that this occurs on and radio installations that cause it?
Help much appreciated
-Dan
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PZL Pilot
I made the LO suggestion and would like to clarify that we don't know yet that it is a real problem - just a slightly more plausible explanation for problems with hand helds than some of the others (jamming, broadcast transmitters, etc)., which can't account for the approx 30 min or 50mi outage that I experienced from the river Shannon to Kerry airport.
Also bear in mind that the LO doesn't have to be in a radio - it could be in a nav box, the ADF or even the DME. What fits well is that it would likely affect aircraft with old radios and suction cup hand held GPS antennas.
There must be radio engineers out there who could make a more informed comment on the plausibility of this 'explanation'. I'm also sure it would be possible to make an 'interference detector' monitoring spurious radiaton on GPS frequencies and indeed such a thing probably already exists. Help anyone?
David
I made the LO suggestion and would like to clarify that we don't know yet that it is a real problem - just a slightly more plausible explanation for problems with hand helds than some of the others (jamming, broadcast transmitters, etc)., which can't account for the approx 30 min or 50mi outage that I experienced from the river Shannon to Kerry airport.
Also bear in mind that the LO doesn't have to be in a radio - it could be in a nav box, the ADF or even the DME. What fits well is that it would likely affect aircraft with old radios and suction cup hand held GPS antennas.
There must be radio engineers out there who could make a more informed comment on the plausibility of this 'explanation'. I'm also sure it would be possible to make an 'interference detector' monitoring spurious radiaton on GPS frequencies and indeed such a thing probably already exists. Help anyone?
David
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I recall that a particular harmonic of some DME frequencies, can overlay the GPS spectrum. The power levels involved there are (hopefully!) orders of magnitude above local oscillator emissions.
Then you have things like wingtip strobe inverters. How many peoples' radio transmissions are badly affected by these? Lots and lots. Again, lots of power combined with ancient unshielded or badly shielded wiring which was probably never done right to start with.
I am completely certain that many handhelds work due to as much luck as anything else, especially those with integral aerials used in metal cockpits. This does occassionally affect reception and, sadly, is constantly used by the anti-GPS brigade to show how evil GPS is...
As I have said here many times, GPS should be brought fully into basic training somehow, but to do so would require properly installed (panel mounted) units with rooftop aerials. The cheapest decent panel mount GPS is probably the KMD150 (£2000 or so) and a rooftop aerial is about £300. All plus installation.
Then you have things like wingtip strobe inverters. How many peoples' radio transmissions are badly affected by these? Lots and lots. Again, lots of power combined with ancient unshielded or badly shielded wiring which was probably never done right to start with.
I am completely certain that many handhelds work due to as much luck as anything else, especially those with integral aerials used in metal cockpits. This does occassionally affect reception and, sadly, is constantly used by the anti-GPS brigade to show how evil GPS is...
As I have said here many times, GPS should be brought fully into basic training somehow, but to do so would require properly installed (panel mounted) units with rooftop aerials. The cheapest decent panel mount GPS is probably the KMD150 (£2000 or so) and a rooftop aerial is about £300. All plus installation.
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Some interesting points, I think I may try to contact a radio engineer.
I understand what you are saying David, wasn’t trying to quote you as saying there was a particular problem, sorry if it came across wrong.
IO540 - I agree, if the anti GPS brigade were a bit more open for discussion then people may be more willing to come forward with there experiences.
With regards to getting GPS into the PPL, perhaps it may be a good step to include it in the Navigation theory –that way people may understand the limitations of GPS thus increasing safety?
I understand what you are saying David, wasn’t trying to quote you as saying there was a particular problem, sorry if it came across wrong.
IO540 - I agree, if the anti GPS brigade were a bit more open for discussion then people may be more willing to come forward with there experiences.
With regards to getting GPS into the PPL, perhaps it may be a good step to include it in the Navigation theory –that way people may understand the limitations of GPS thus increasing safety?
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May I suggest to the anti GPS brigade that to argue this subject with you is about the same as arguing the horse and buggy vs the automobile.
I have used GPS ever since it came on the market all over the planet in my ferry business. Both the VFR panel mounts, the VFR hand helds and the IFR approved panel mount units.
I found that GPS is mroe accurate by far than any other navigational tool and has a reliability factor equal to or superior to any other method of navagating.
The hand helds are as reliable and accurate as the panel mounts, at least that has been my experience.
So if it is the prefeered mothod that we use for navagationg , why is it not good enough for the sunday afternoon private pilot?
Oh well I guess to each his own.
I have used GPS ever since it came on the market all over the planet in my ferry business. Both the VFR panel mounts, the VFR hand helds and the IFR approved panel mount units.
I found that GPS is mroe accurate by far than any other navigational tool and has a reliability factor equal to or superior to any other method of navagating.
The hand helds are as reliable and accurate as the panel mounts, at least that has been my experience.
So if it is the prefeered mothod that we use for navagationg , why is it not good enough for the sunday afternoon private pilot?
Oh well I guess to each his own.
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PZL Pilot. Thanks. By the way I thoroughly endorse what you are doing. If we can dispel some of these GPS myths, GA would be safer all round.
IO540 Very interesting points. I had sort discounted other sources of EMI (Electromagnetic Interference) in the plane because of the apparently geographic nature of the anecdotes and the fact that the problem would be apparent on the ground, which includes leaving a cell phone on.
However, the DME is another matter. I had forgotten that it transmits at around 1Ghz, much closer to GPS than nav/com. I am also reminded that we have had problems with the push in signal connectors in the DME tray, such that it is sometimes neccessary to push on the front of the DME to restore the range readout.
Obviously when this connection is poor, signal must be leaking into the cabin... and I think that the DME just transmits 'blind' if it doesn't get a response. Could anyone comment please? I bet a leaky transmit connector changes the antenna impedance and has the potential to cause nasty harmonics as well.
So my checklist for the next GPS 'outage' (I've only had one in 200-300 hrs) includes switch off DME!
David
IO540 Very interesting points. I had sort discounted other sources of EMI (Electromagnetic Interference) in the plane because of the apparently geographic nature of the anecdotes and the fact that the problem would be apparent on the ground, which includes leaving a cell phone on.
However, the DME is another matter. I had forgotten that it transmits at around 1Ghz, much closer to GPS than nav/com. I am also reminded that we have had problems with the push in signal connectors in the DME tray, such that it is sometimes neccessary to push on the front of the DME to restore the range readout.
Obviously when this connection is poor, signal must be leaking into the cabin... and I think that the DME just transmits 'blind' if it doesn't get a response. Could anyone comment please? I bet a leaky transmit connector changes the antenna impedance and has the potential to cause nasty harmonics as well.
So my checklist for the next GPS 'outage' (I've only had one in 200-300 hrs) includes switch off DME!
David
The Boscombe BAC 1-11 did trials on DME/GPS at Edinburgh (I think) years ago. ISTR relative aerial siting solved the problem. No doubt the UK CAA are hard at work coming up with another problem. My experience mirrors Chuck's, and includes GPS mapping systems throughout the Pacific, Australasia, & SE Asia. GPS works, but has limitations under certain circumstances - operational procedures are devised to cope with those cirumstances......
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Reynolds
What do you mean by "GPS works, but has limitations under certain circumstances "
As a new user of gps, who has no training with gps (but only uses it to double check my visual nav), I'd like to know about limitation that other have found.
thanks
dp
What do you mean by "GPS works, but has limitations under certain circumstances "
As a new user of gps, who has no training with gps (but only uses it to double check my visual nav), I'd like to know about limitation that other have found.
thanks
dp
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david viewing
Yes, a DME transmits all the time (with a pseudo-randomly varying period I believe) regardless of whether it gets a response.
GPS uses about 1.5GHz but frankly you would need a pretty well designed 1.5GHz receiver to be unaffected by getting hit with say 100 watts at 1GHz. Another reason for a rooftop GPS aerial - the DME aerial is usually underneath.
Yes, a DME transmits all the time (with a pseudo-randomly varying period I believe) regardless of whether it gets a response.
GPS uses about 1.5GHz but frankly you would need a pretty well designed 1.5GHz receiver to be unaffected by getting hit with say 100 watts at 1GHz. Another reason for a rooftop GPS aerial - the DME aerial is usually underneath.
dp - as a VFR user you will only ever use it as a supplementary aid to navigation, so there is no training requirement (you don't receive radio nav.aid training for a PPL, right?). As mentioned, there are harmonics of the GPS frequncies that may cause interference - result is your GPS will not work, so no problem, you can't use it. Major handheld problem is probably"fat finger syndrome" - putting in the wrong information, or reading the wrong information. Keep your eyes on the outside!
IFR use is slightly more problematic as there is the navigation integrity requirement to deal with, which requires more satellites in view than for a 2D navigation solution alone. Coupled with the receiver mask angle (that eliminates low horizon satellites from the navigation solution), this can create an availability issue. Integrity monitoring prediction services can assist in the operational planning aspect of this.
IFR use is slightly more problematic as there is the navigation integrity requirement to deal with, which requires more satellites in view than for a 2D navigation solution alone. Coupled with the receiver mask angle (that eliminates low horizon satellites from the navigation solution), this can create an availability issue. Integrity monitoring prediction services can assist in the operational planning aspect of this.
