Here's a thought. If all the OP wants is a measure of association (correlation), he can use a function of the form:?ÿ PDOP = a +b*(Horizontal Precisio...

Perhaps the relationship is not linear. Look carefully at your scatterplot. You may have something like the graph below, where the actual relationship...

Here are the disclaimers for two county GIS in NC. You can't get to the maps without agreeing. But not all counties have disclaimers; I think they're ...

@mlschumann?ÿ Yes, prior to 1959, there was only one conversion from meters to feet in the US. That was 1 foot = 1200/3937, which has been called the...

The international foot was defined in 1959.

@geeoddmike?ÿ Very well said.?ÿ

@geeoddmike?ÿ Yes, but when one uses NCAT to convert between NAD83 and NAD27, one should look carefully at the uncertainty numbers. Here's a simple o...

Tripod would be good for a boy dog. Can't think of one for a girl.

As long as Lucas isn't involved, it has a chance to work.