Researchers Improve GPS 3D Accuracy

[Guest]

Global positioning systems have become surprisingly accurate in the 2D landscape - certainly much more accurate than what we would have expected about 10 years ago.

Researchers Improve GPS 3D Accuracy : Read more

 

[Hupiscratch]

This will permit outstanding improvements in air navigation.

 

[Trialsrider]

Reads like hype. No comparative numbers just technobabble. "required knowledge of three or four reference stations in order to perform the calculations properly". Isn't that called differential GPS which is already used by anyone requiring precision.


Probably powerd by cold fusion.

 

[ecrenshaw]

Trialsrider,
Not exactly. DGPS is run by the coastguard and was developed to increase accuracy, mainly for around the coastline. It does not use nor send altitude information. The DGPS antenna only send out the error in the area which DGPS receivers use to lower the error in their calculations.

My eTrex has a pressure sensor that gives the altitude. That is how planes do it. I don't know why they would use GPS to calculate it when pressure sensors or even radar altimeters should be more accurate.

 

[gm0n3y]

I have a Garmin Edge 500 and the altitude always seems reasonably accurate, though I wouldn't want to rely on it for any life and death situations. I always just assumed that it used a barometer to judge elevation. You can always assign preset altitudes to different locations and this will help to improve the accuracy. I assume that for higher end models you can also import a map that includes altitude points.

 

[skylanemurf]

DGPS (WAAS) does improve vertical accuracy. Look it up. Pilots use GPS for vertical guidance in RNAV (RNP) approaches.

 

[ecrenshaw]

jeffmoreno,
while it does improve accuracy it is generally 1.5 times greater than the error in the horizontal plane (not the thing flying, but the xy axis plane). Generally, I have measured WAAS accuracy to be about 4-6m after averaging for over an hour at one location. DGPS has about the same accuracy but it is NOT available in every part of the US. DPGS and WAAS are different. WAAS uses two geosynchronous satellites to broadcast the error while DPGS uses ground based antennas. Generally, aviators do not use DGPS.

In addition, they usually don't use GPS for the elevation because it is so inaccurate. maybe this new system will help but there are other more dependable and readily available methods to do so. Also, for most small plane I would guess that the pilots don't use GPS for the elevation and when they REALLY need the elevation to be accurate there are land based augmentation systems to help them out.

 

[tank]

Ecrensha,
I am a Certified Flight Instructor for airplanes, we use GPS to determine our lateral distance between objects and our altimeter is used for our altitude because that is the most accurate way to determine elevation with the pressure changing constantly. However this idea of an accurate GPS location by positioning either satellites or ground stations is not a new concept. This has been in practice for over 5 years now for GPS approaches. A GPS approach is considered a non-precision approach. When precision is needed we use what is called an ILS type approach. This will guided the pilot at a 3 degree (normally) descent path to the runway.

However this being said, this is not a new concept of ground stations making GPS more accurate. I like it, this means every airport could potentially have a precision approach. Score for the aviation community.

 

[dalmvern]

Being a surveyor, GIS analyst, and pilot this is all good news, however I agree with what Trialsrider says, this is very hyped. And as Tank said, not a new concept, they are just improving on old ideas and possibly making them feasible.

I think the real gist of it is that they improved on how we are doing it currently so it is more accurate, but I doubt GPS will ever be as accurate as a standard altimeter.