NARDA IDA, Operating Manual, Page: 143 / 292

7.4 Horizontal Scan
Narda IDA - 3106
135
7.4.1 Continuous Horizontal Scan (Continuous)
Direction Finding (Horizontal Scan: On)
The IDA - 3106 continuously measures the signal level and saves the values
as the antenna is panned horizontally. The measurement is stopped
manually after a sufficient number of measured values has been obtained.
The actual alignment of the antenna, the field strengths measured during the
scan, and the calculated transmitter bearing are shown in the polar diagram.
Warning messages indicate if the antenna is not held correctly or if no
meaningful results could be obtained.
NOTE:
Further information on using polar diagrams and interpreting the results is
found under
Horizontal Scan in practice
on page 269.
To make a Continuous Horizontal Scan:
1.
Set the measurement parameters as desired. Above all, select a short
averaging time (max. 0.48 s), since longer averaging times require the
antenna to be panned more slowly.
2.
Check the polarization (horizontal / vertical):
– Tip the antenna by 90°: The maximum signal strength is displayed
when the polarization is correct.
– If necessary, change the position of the antenna module in the holder.
3.
Press the
Scan Type
softkey and select
Continuous
.
4.
To start the measurement, press the button on the antenna handle or
press the
Start Continuous
softkey.
5.
Pan the antenna horizontally through 360°, taking about 20 seconds to
do this (pan more slowly if you are using an averaging time > 0.48 s).
Keep the antenna as horizontal as possible while you do this.
6.
When you have finished the scan, press the button on the antenna
handle or press the
Stop
softkey.

If the scan is successful, the red arrow in the polar diagram indicates
the direction of the signal source that was determined. The result is
also shown numerically.
7.
Press the
SAVE
key on the Basic Unit to save the measurement results.

A window shows the save process.
8.
To start a new measurement, repeat the steps from step 4 onwards.
(Starting a new measurement automatically resets the instrument.)
NOTE:
If you pan the antenna too quickly or tilt it by more than 15° horizontally or
vertically (elevation: ±15°, polarization: ±15°)
Azimuth uncertain
will be
displayed in red to indicate that deviations can occur in the bearing that is
determined.