NARDA IDA, Operating Manual, Page: 276 / 292

18 Annex
268
IDA - 3106 Narda
18.1.2 Panning speed
To ensure that reliable results are obtained for a Horizontal Scan, the
antenna must be slowly and steadily panned as well as being kept
horizontal. As a general rule,
panning through 360° should take at least
20 seconds
(AVG of 0.48 s). If you pan the antenna too quickly, the bearing
will be falsified by the averaging time and deviations between the signal
level and the corresponding compass data. Ideally, panning should be in a
smooth line without interruptions. In the same way as when the elevation
and polarization angles are exceeded,
Azimuth uncertain
is displayed to
indicate that the result is too inaccurate if you pan the antenna too quickly.
Figure 60: Panning was too fast. There are large gaps between the blue
measurement points, so the display shows Azimuth uncertain.
Figure 61: Panning was slow and steady. The blue measurement points are close
together over the entire measurement curve.
NOTE:
A new measured value is recorded and displayed on the polar diagram
every 120 ms in Horizontal Scan Continuous mode. This represents 167
values spaced less than 0.5° apart in a full rotation (360°) taking
20 seconds.