topic Re: Finding routes in ArcGIS Spatial Analyst Questions

Finding routes

ModyBuchbinder — Mon, 20 Aug 2012 12:26:22 GMT

Hi all

I need some ideas on how to perform some analysis. Here is the problem.
We have some GPS points of moving cars.
The GPS is not accurate and the delta from the real location can be 50 meters or more.
We create lines from the points. We might snap it to roads network but in some cases in city the points can snap to the wrong street.
What we are looking for is places where the person drove only once (or only twice).
Because the route is not accurate we must translate the lines into raster in some kind of Kernel Density process and then check the raster.
The problem is that if we have two lines the raster value is higher than if we have one line but when we move away from the two lines value we get similar values to the one line values.

Can anybody think about a nice way to do it?

Thanks
Mody

Re: Finding routes

JeffreySwain — Tue, 21 Aug 2012 11:03:27 GMT

Why not interpolate the line created with the horizontal position to match the existing DEM? That would avoid the snapping issue and trying to choose the correct one. The interpolated vertical would be more dependent on the horizontal accuracy provided, but should avoid the issue of trying to choose the correct vertical line to choose.

Re: Finding routes

ModyBuchbinder — Tue, 21 Aug 2012 11:45:33 GMT

Hi

I am not sure if I did not understand the answer or you did not understand the question.
Let me explain it again.
I divide the area into 50 meters boxes. I need to know who many lines crosses each box.
If I translate it to vector and I have 50X50 KM then I have 1M boxes and have to select 1M times the line layer to get the value for each one.
That is why I need a way to make it using raster.
I do not have any DEM here.

Thanks
Mody