[Loadstone] User Range Error
Rob Melchers
rob at loadstone-gps.com
Mon Dec 3 11:37:27 GMT 2007
Because a lot of LS users didn't know what to do with the accuracy value
that is obtained from the receiver we followed a rule of thumb that says
that multiplying that value by 8 gives sort of an accuracy reading in
meters. So, if the receiver gives an accuracy value of 1.5, this results in
an estimated accuracy of 12 meters, the range in which you can be sure your
target lies. If you increase the multiplication factor, the result
obviously becomes greater, meaning a lesser accuracy. Since in urban
canyons reception is less accurate it makes sence to 'translate' the
receivers reading into something less accurate. Another interpretation of
the accuracy values coming from the receiver can be found in the list on
the 'GPS receivers: how they work' page. It's like with miles and
kilometers, you can express the same features using different measures, the
real distance stays the same.
Rob
At 12/3/2007, you wrote:
>Hi Shawn!
>So the value I set in the User Range Error setting is the factor by
>which the accuracy value from the receiver is multiplied? I still don't
>understand of what use this is. Why should I want to multiply the
>receiver's output by anything? What's the advantage of altering the
>receiver's output to any degree?
>By the way, the info that higher values produce more accurate readings
>in urban canyons comes from the documentation.
>Cheers,
>Robbie Sandberg
>-----Original Message-----
>From: loadstone-bounces at loadstone-gps.com
>[mailto:loadstone-bounces at loadstone-gps.com] On Behalf Of Shawn
>Kirkpatrick
>Sent: 03 December 2007 10:26
>To: loadstone at loadstone-gps.com
>Subject: Re: [Loadstone] User Range Error
>
>The user range error setting is multiplied by the accuracy value from
>the
>gps receiver to give an estimated accuracy in metres. I doubt a higher
>value
>would give you better results. You can probably use the default of 8
>unless
>you know that your receiver does better or worse.
>
>On Mon, 3 Dec 2007, Sandberg, Robert wrote:
>
> > Hi folks!
> > I've read the documentation and the article on GPS receivers and I
>still
> > don't know what the accuracy setting does.
> > I understand that the accuracy of a reading can vary, depending on the
> > environment, I.e. open country or inner city. But I don't get what the
> > setting in Loadstone has to do with it, or why higher values should
> > produce more accurate readings in urban canyons. Can someone put me
>out
> > of my misery please?
> > Cheers,
> >
> > Robbie Sandberg
> >
> >
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