2007-03-09 21:22:12 · 7 answers · asked by Anonymous in Cars & Transportation ➔ Aircraft
Several ways.
Different nav systems including GPS or radio nav systems to measure actual ground speed.
Different sensors that detect how fast plane is going through the air (pitot) help determine airspeed. Plus if you know any two of wind velocity, ground velocity and airspeed you can calculate the third.
2007-03-09 21:32:38 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Airspeed is measured by measuring the pressure and spped of wind which the aircraft is flying in that is called releative wind.
Ground speed can be measured by using radio navigational equipment such as DME but accurate readings of ground speed can be obtaind from a GPS device.
2007-03-10 10:49:45 · answer #2 · answered by TimTim 3 · 0⤊ 0⤋
It uses pitot tubes to measure the speed of the air going past, ground speed is most commonly measured nowadays with GPS, it gives you a readout with no calculation. Otherwise, you would have to use a DME or VOR and calculate your speed and even then it wouldnt always be accuarate. Airspeed is the important one, used nearly all the time when flying.
2007-03-10 10:31:45 · answer #3 · answered by ALOPILOT 5 · 0⤊ 0⤋
Air speed is measured by taking the differance between the static air pressure (from a small hole usually on the side of the airplane and at right angles to the airflow so the air flows across the opening) and the ram air pressure (using what's called a pitot tube which is positioned so the air flows straight into it). Ground speed is simply calculated by timing how long it takes to fly between two points a known distance apart. if you take 30 minutes to fly between two points that are 50 nautical miles apart, your groundspeed is 100knots! (100 nautical miles per hour)
GPS is used a lot now but it uses the same principle and you don't need it to calculate groundspeed, just a chart, a watch and something to measure the distance on the chart!
2007-03-10 17:39:03 · answer #4 · answered by bevl78 4 · 2⤊ 0⤋
One additional method of measuring ground speed not mentioned above is by Doppler radar. The military has used that system for about 50 years.
2007-03-10 12:26:39 · answer #5 · answered by Anonymous · 0⤊ 0⤋
pitot tube - airspeed
ground speed can be calculated by distance to a known radio signal beacon by a DME
2007-03-10 05:26:01 · answer #6 · answered by tom4bucs 7 · 1⤊ 0⤋
well its like a car its got a dial
2007-03-10 05:26:15 · answer #7 · answered by Adam B 2 · 0⤊ 2⤋