User Manual

Search Operations (Cont.)

32 RDR-1600 Pilot’s Guide TM106101(8/01) TM106101(8/01) RDR-1600 Pilot’s Guide

7.1.2Other Aircraft

Tests show that only with extremely careful observation at relatively short

ranges can other aircraft be detected by this type of radar equipment. The

character of this echo is such that this type of radar system cannot be

considered adequate for this purpose.

7.2SEARCH MODE

An advantage of this radar system is the enhancement of short range

mapping capability. This facilitates locating specific targets on land or sea

and provides a navigational map as a supplement to standard navigation

procedures.

7.1.1Looking Angle

The incident angle at which the terrain is illuminated has a direct bearing on

the detectable range and the area of illumination. A large incident angle

gives the radar system a smaller detectable range of operation (due to a

minimized reflection of direct radar energy). However, the illuminated area

“A” is larger.

Figure 7.1.1-1.A Smaller Incident Angle

A smaller incident angle gives the radar a larger detectable range of oper-

ation because of an increase of direct radar energy reflected from the

target to the antenna. The area of illumination (“A”) is smaller.

Figure 7.1.1-2.Concentration of the Beam

Concentration of the beam energy on the small area of terrain increases the

magnitude of the echo intercepted by the antenna. The resulting detectable

range is therefore increased for mountainous terrain; the maximum

distance at which this terrain can be monitored is greater because of the

more direct reflection (or radar echo) produced. Illuminating the backslope

of hills stretches the area of coverage beyond the flat terrain coverage.