User's Manual

12 DRAFT P440 Data Sheet / User Guide
 Display range measurements taken between other units in the area for which the connected
P440 is not a direct participant.
Fig. 3: Typical waveform as displayed by the GUI
The ability to log data also allows the user to plot performance as a function of range. This is an
excellent tool for evaluating signal propagation in a given area. For example, the information shown
in Figure 4 was collected as the distance between two units was increased. Basically, one unit was
stationary while the second unit was slowly driven away. Figure 4 shows a plot of the Signal, Noise,
and SNR as a function of separation distance. In this figure one can observe several items of note:
 There is a Fresnel cancellation at 40, 60, and 100 meters.
 There is a Fresnel enhancement at ranges greater than 120 meters.
 The noise floor is constant; therefore there are no significant interference sources in the
vicinity.