CSPM - Communication System Performance Model 

The Communication System Performance Model program creates
detailed shaded or contour plots of basic transmission loss,
field strength, power density, or signal-to-interference ratios
from a transmitter in a given geographical area.  It uses the ITS
irregular terrain model(ITM) in the point-to-point mode for
determining path loss along radials of about one degree azimuthal
intervals around the transmitter.  The ITM propagation model is
applicable to analyze mobile, broadcast, or radar coverage and
interference problems in the 20 MHz to 20 GHz band.  ITM is the
same propagation model that is used in the RAPIT program.

CSPM calculates path losses in a user-defined geographic area. 
This area is divided into a grid of up to 200 x 200 points for a
maximum number of calculated values of 40,000.  These path losses
are used in the generation of a plot and are converted to the
desired output type (field strength, power,etc) at plot time. 
This is important for the user to know because if you wish to
change an input data item and see the effect of that change on
your analysis, you may be able to perform this change without re-
running the cspm calculations.  Instead of running CSPM, you can
run CSPM_PLOT and chose item 4 (replot - edit input data).  This
program will allow you to edit your input data and will warn you
for those items that will require a rerun of the calculations. 
If you do not change any critical items, the replot will be much
less costly than rerunning the calculations.  See CSPM_PLOT for a
description of it's capabilities.

There are four basic output plot types available from CSPM.  One
plot is a text based line printer plot, the second is a pen plot
on paper, the third is a FAXed plot and the fourth is an HPGL
graphics file.  The line printer output gives the signal level at
each of the up to 200 x 200 points rounded to the nearest 4db.
The pen plot is a color plot and can show up to five contours of
signal level within the plot area along with other optional
information such as landmarks and political boundaries.  Since we
store the basic input and output data, you may retrieve the input
data at a later time and modify this data for a new analysis or
you may replot the data.  Replots may include plots on
transparency material that can overlay maps or charts of the area
of interest, plots of different sizes or contours than those
originally chosen and plots zooming in or expanding some portion
of the plot area.  Some of these options will require
intervention by the TAS staff and incur a separate charge.  Large
plots are arranged for by telephone contact.

For further information, please read the individual user's guides
for each program or call TA Services at (303) 497-5301 or FAX
(303) 497-3602.