Re: Roughtly converting DOP to metric error


<speleoluc@xxxxxxxxx> wrote in message
news:cf358fde-d297-4637-a04a-7054efe23e33@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi,

My cave survey freeware connects to a GPS for surface tracking. When I
connect to a Bluetooth GPS, the GGA and GSA NMEA sentences provide
various flavors of DOP values (PDOP, HDOP, VDOP). How can I provide
users with a rough error value in meters (as most GPS units do) from
these unitless numbers?


Luc Le Blanc
http://www.speleo.qc.ca/Auriga

DOP is a multiplicative factor, and is used to increase metric errors
calculated by other means; so to evaluate it's effect you would need to know
the reported metric error and whether or not the DOP was already applied to
it. This is a pretty simplistic answer; I'm sure others will weigh in with
more detailed answers :-)

John


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