I'm working on flight sensors for a project and I'm supposed to model GPS device noise. I looked a lot for it online and could not get a convincing answer.

I need the uncertainties of altitude and Lat/Long measurements from an aviation grade GPS device such as a GARMIN GTN 750. By uncertainty I mean + or - certain metres for altitude and + or - certain degrees for Lat/Long.

I found just one web page mentioning the vertical uncertainty as 10m but again there was no reference attached to it and nothing for Lat/Long.

closed as too broad by user30184, Dan C, whyzar, lynxlynxlynx, tinlyx Sep 11 '17 at 17:42

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  • what receiver and corrections are you using? Positional uncertainty is going to be directly based on this. – risail Sep 11 '17 at 13:29
  • There is no real receiver. All these are for simulation purposes only and I'm in dire need of realistic values of uncertainties for the GPS altitude and GPS Lat/Long. – controlfreak Sep 11 '17 at 13:32
  • You should probably pick a unit and simulate to the manufactures specs. What your asking is going to be answered in whatever receivers manual you choice. – risail Sep 11 '17 at 13:37
  • I did check up on that and I came to know that GARMIN products are used for a lot of aviation purposes and in their website, they don't have this information in the product specification section. – controlfreak Sep 11 '17 at 13:44
  • add the unit to the question I'm sure someone here can answer it. – risail Sep 11 '17 at 13:46

According to the spec sheet of the Garmin GTN receiver the accuracy is 1m.

Since you are simulating I would use the FAA's range of 1.5 horizontal and vertical:

The WAAS message improves the accuracy, availability and integrity of GPS-derived position information. Using WAAS, GPS signal accuracy is improved from 20 meters to approximately 1.5 – 2 meters in both the horizontal and vertical dimensions



  • But is the 1m accuracy is for position or altitude? – controlfreak Sep 11 '17 at 14:31

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