can gps take the place of dme in aviation?

Answer 1

GPS is already taking the place of DME. Many airports have switched their VOR/DME approaches to GPS. VORs are expensive to equip and maintain, and I forsee the FAA phasing them out over the next 25 years.

Unless the airport wants a precision approach, no special equipment needs to be at the airport. For 2-D location, the airplane can get everything it needs from the normal GPS satellites. For 3-D precision location, and Category 1 ILS, the airport or area needs a LAAS or WAAS station to correct for GPS variations at that location.

Answer 2

Actually, no. A GPS, though highly accurate will give a distance from a point in nautical miles, using spherical trigonometry based on the WGS 84 ellipsoid. All very well, and it is an accurate reading, however, A DME does not give an accurate reading. DME will give a slant range, based on the reception of the pulses from the base station / DME Receiver. Although not as accurate. I was informed that should i be asked a distance when flying if I use the GPS to say "xxx miles" but If I'm using the DME I have to say "xxx DME" that way if there is any discrepancy I'm covered. DME will give you a pythagorean triangle range (E.G. DME Station is 4 miles on the ground from the aircraft position, Aircraft is 3 miles high (18240 feet high) then the DME will give me a range of 5 Miles. The GPS will only give me 4)

Answer 3

Yes & no. DME works on the principle of direct line of sight from the antenna to the aircraft which is a diagonal line (hypotenuse) when an aircraft is at altitude. The higher up in altitude, the longer the actual distance. GPS, even though it will show your altitude, displays it's ground distance to the navaid in a straight line (actually slightly curved with the curvature of the earth over long distances).

The nearer you are to the navaid, the greater the error will be - especially an airliner at high altitude. 30,000 feet is about 5 and a half miles, so when the airliner is directly over the navaid, the DME will read 5.5 miles, but the GPS will read ZERO.

Answer 4

A DME arc flown with a GPS? While convenient it is, however, illegal.
The Approach must be annotated and predicated upon GPS (either stand alone or overlay)
The GPS must be TSO'd and certified for approaches (or en-route only)
Previous answers are correct regarding slant-range vs ground distance and someone flying , for instance, a 7nm DME arc at FL100 will be (painfully) obvious to GCA if it's being done on a GPS versus a DME

Answer 5

GPS has already replaced DME in many aircraft including general aviation planes. It's much more reliable as well!

Answer 6

Of course. GPS is way more accurate though. Ever heard of DME arc IFR approaches? Done many of them without a DME bacause I had a GPS.

Answer 7

Yes it can, if your GPS has that function available.

DME gives you the direct-line distance and direction to a fixed radio transmitter from your receiver. A GPS can do the same thing if you can program the transmitter location coordinates into it.

Answer 8

It most certainly can! GPS can do so much more too! In several years the GPS will be somewhat of a centerpiece for the ADS-B system (Automatic Dependant Surveillance Broadcast) that the FAA will replace it's current ATC system with. As far as technology in the cockpit, everything keeps getting better!

Answer 9

Already has. I have three GPS's on my airplane and I almost never use DME and would never HAVE to use it.

Answer 10

GPS includes DME, doesn't it?