Radar System Engineering

f$Ec. 614] PRECISION TRACKING OF A SINGLE TARGET 209
embodied in the design because its precision of following is, unlike the
accuracy of manual tracking, not subject to human errors arising from
combat stresses and fatigue> G r 3 t. -,, . : >.,
In order to ensure that the error signals are ~easured with respect
to the desired radar echo only, and also to provide a continuous measurement
of range, two type J displays are presented to the range operator
of the radar. These are circular range sweeps (Sec. 6.4) with radial
signal deflection. The coarse range scope shows all ranges out to a maximum
of 32,OOOyd. and the fine scope shows a magnified trace of a 2000-yd
FIG. 6.37.—SCR-584 in operating position.
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interval which can be chosen anywhere \vithin the 32,000 yd. Markers
geared together at 1 to 16 and driven by the range handwheel are in front
of these tubes. W-hen the marker on the 32jO00-yd tube is put over the
signal echo to be tracked, the 2000-yd tube displays a range interval 1000
yd on either side of the target range. The marker on the 2000-yd tube
can then be set exactly on the leading edge of the target signal. When
this adjustment is made the marker is kept in register with the desired
signal, and continuous target-range information is sent to the computer.
Further, only those signals which come in a range interval of about 50 yd
immediately following the range for which the marker is set are sent to
the input of the angle-error measuring circ~lits.