I wish to plot Kernel Density Map for geo-referenced rural road crashes in ArcMap 10 (using Spatial Analyst Tools->Density->Kernel Density-Dialogue box pops up to enter data). I found that the "Output Cell size" and "Search Radius" by default the ArcGIS software is taking for plotting Kernel density Map for road crashes is very small say 0.001 metre(m) and 0.01 m respectively, which is small to conclude inferences from the plotted kernel density maps. When I change"output cell size" and "radius" in the Dialogue box to larger values say 5 m and 50 m respectively, ArcGIS does NOT plot the kernel density map and show error. Could anyone help me to diagnose the problem in plotting kernel density maps for road crashes. Secondly I also request the esteemed members to write steps or procedure to carry out Network Density Estimation using ArcGIS as Kernel Density estimation is planar based and not popular in analysing highway crashes.
Thanking you in advance.
Reply to the cited query may be posted at my email account: naqvihm@gmail.com
H. M. Naqvi
What coordinate system is your data in? Sounds like there is a mismatch between the coordinate system (geographic degrees perhaps) and you distance. 50 in degrees is a long way.
Probably need to get the data into a projected coordinate system first.