[Geopriv] How do you return error

From: Rosen, Brian ^lt;Brian.Rosen@neustar.biz>
Date: Thu Jul 17 2008 - 21:26:18 EDT

So far, in the discussions on error, the way it's proposed to specify
error is that the location return is a shape representing the
confidence, and uncertainty is returned as a scalar.

I'd like to question that proposal.

In every other engineering system I'm familiar with, you return the
nominal value and you express the error. So you might get a measurement
of 1.077 meters, plus or minus .03 meters.

Why are we not returning that kind of response here?

If we ask for a location, we should get a point and an error. The error
may be a shape, but 99% of applications would be satisfied with a few
scalers (circular or ellipsoidal error).

You shouldn't have to do calculations at the watcher to get the nominal
point, especially if the shape is not circular or ellipsoidal.

Most consumer systems work that way. Most real apps want data that way.

Specific proposal:

Return location normally as a point (2 or 3 space).
Return error as metadata: a shape with optional distribution & optional

It's conceivable that we need OGC to help with this. Fine.

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Received on Thu, 17 Jul 2008 21:26:18 -0400

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