Phase II Final Report - NASA's Institute for Advanced Concepts

Planetary Exploration Using Biomimetics
An Entomopter for Flight on Mars
Table 4-2: Parameters for Altimetry Analysis (Continued)
Signal-to-noise ratio (dB) 10
Interpulse period, T (ms) 1
Pulse repetition frequency, (kpps) 1
Following the analysis procedure outlined above, the required peak and average transmitter
powers are shown in Figure 4-18 for an operating frequency of 18 GHz. The peak and average
powers for a 10-m altitude are 3.9 µW and 1.6 pW, respectively. The peak and average powers
for a 200-m altitude are 630 mW and 252 nW, respectively. Note: The required peak power has
increased significantly compared to the obstacle-detection results due to the increased range resolution.
The required peak and average powers are plotted as a function of operating frequency
in Figures 4-19 and 4-20, respectively. These plots show that by decreasing the range resolution,
and thus decreasing the pulse width (see Equation 4-16), the frequency dependence is altered
compared to the obstacle-detection results. These plots also show that a reduction in required
power can be achieved by operating below about 2 GHz. However, using the chosen pulsewidth,
physically realizable operating frequencies are limited to values greater than 1.25 GHz to maintain
a bandwidth greater than twice the operating frequency.
0.1 1 0.01
1.10 3
1.10 4
1.10
1.10 6
5
1.10 7
1.10
1.10 9
8
1.10 10
1.10 11
1.10
1.10 13
12
1.10 14
0 50 100 150 200
Range (m)
Peak
Average
Figure 4-18: Peak and Average Transmitter Power Required for Altimetry at 18 GHz
as a function of Altitude
Power (W)
Peak and average powers at 18 GHz
Phase II Final Report
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