Numeric Measurement Modes
R&S
®
EVSG1000
57
User Manual 1178.6227.02 ─ 06
formed to obtain an initial overview of the input signal and determine the basic signal
characteristics. The displayed measurement results depend on the selected channel
and frequency configuration.
Autotune function
An autotune function is available to determine the precise frequencies of the signal
components automatically. Thus, the demodulation bandwidth can be selected very
precisely. Automatic mode is indicated by "Autotune" in the measurement settings
area, followed by the current processing status.
The autotune process consists of the following steps:
1. "Search": the R&S
EVSG1000 searches the input signal for peaks. You can define
a power threshold that the carrier must exceed to be detected (
2. "Check": the R&S
EVSG1000 checks whether the detected peak is a valid ILS sig-
nal, based on the measured DDM value.
3. "Lock": the R&S
EVSG1000 determines a valid ILS signal and remains tuned to
that frequency.
A valid signal is also indicated by a green DDM measurement result, see
on page 67. In the recorded dataset, the STIOCPM status indicates a
The frequency remains locked until:
● You switch measurement modes
● You change the channel or frequency settings
● You select the
function.
In this case, a new search starts.
Adapting the frequency in autotune mode
The autotune function sets the measurement filter position such that the detected fre-
quency is in the center of the filter bandwidth. While the frequency is locked, the filter
position remains unchanged. If the bandwidth is narrow and the signal frequency
changes, e.g. due to changes of the transmitter, the signal may no longer be covered
completely by the measurement filter. In this case, the measurement results are distor-
ted. If you assume the ILS signal frequency might have changed, we recommend per-
forming a new search using the
Measurement result views
Due to the large amount of different signal parameters, the ILS Localizer and Glidepath
measurements provide multiple views for the measurement results.
ILS Localizer and ILS Glidepath (GP) Modes
