Currently the WnDb data display consists of a pin point for each AP location. How do we display an empirical graph of the power output in order to see what area a particular node covers?

The raw data required comes from a gps receiver correlated with power output readings from a wifi card. This can be recorded by NetStumbler, Dstumbler or Kismet. Another approach would be to hack the WirelessPowerMeter) or use linux wireless-tools and gpstrans directly.

<Insert some sample data here>

The data set consists of measurements of signal to noise ratio (or some other measure of AP power output) for each GPS reading.

The next step is to use this point map data to produce a rough surface approximation of AP coverage. One way to do this is outlined at University of Kansas ITTC Wireless Network Visualization Project. The Inverse Distance Weighted (IDW) interpolation they mention can be computed by a modified Shepard's Method routine from Netlib. The beginning of the file contains a lot of test code so search for PRECISION FUNCTION CS2VAL for relevant comments. This function returns approximate values for a surface based on point map data.

Outstanding questions:

Long term ideas:

--AaronJohnson


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