Page 62 - Autonomous Mobile Robots

Millimeter Wave RADAR Power-Range Spectra Interpretation 45

in representing dependencies due to occlusion. Jose and Adams [15] show a
method of feature detection from MMW RADAR noisy data.

2.3 FMCW RADAR OPERATION AND RANGE NOISE
This section gives a brief introduction to the RADAR sensor used in this work
and the FMCW technique for obtaining target range. This is necessary for
RADAR signal interpretation and for understanding and quantifying the noise
in the range/power estimates. This is ultimately used in predicting range bin
observations given the predicted vehicle state, in a mobile robot navigation
framework — which is one of the goals of this chapter. By analyzing the FMCW

techniqueitwillbe shown which noise sourcesaffectboth the range and received
power estimates, and how each of these is affected.
The RADAR unit (from Navtech Electronics) is a 77-GHz FMCW system.
The transmitted power is 15 dBm and the swept bandwidth is 600 MHz [16].
The RADAR is shown in Figure 2.1, mounted on a four-wheel steerable vehicle.
Figure 2.2 shows a schematic block diagram of an FMCW RADAR transceiver.
In Figure 2.2, the input voltage to the voltage control oscillator (VCO) is

◦
FIGURE 2.1 A 360 scanning MMW RADAR mounted on a vehicle test bed for SLAM
experiments within the NTU campus.

© 2006 by Taylor & Francis Group, LLC

FRANKL: “dk6033_c002” — 2006/3/31 — 17:29 — pau