**LOS Algorithm Analysis**

To perform, right click on the LOS window and select Algorithm Analysis.

Pick number of algorithms to use and set algorithm parameters.

The computer will draw the LOS profiles in a single graph window, which can be rescaled as desired to see the individual points. They are colored visible or masked.

The top profile with the first algorithm will be drawn with the correct vertical scaling; the other profiles will be dropped down to clearly show the effects.

This analysis used three algorithms:

- Top used a radial spacing.
- Middle used a grid square sides (Yoeli/DYNTACS). Note the variable spacing, with two points close together where the profile clips a corner in the data grid.
- Bottom used a nearest grid neighbor (Bresenham). Note the occasional bumps and steps, where in steep terrain you get very different results depending on which side of the profile the nearest point occurs. Note that this is the only one of the algorithms to show masked terrain about 100 meters from the observer, because the third point out creates an artificial bench.

*Last revision 7/16/2004*