User manual

Code: ENIGMA III User Manual
Edition: 1 Revision: 4
Date: 19/12/2008
Page: 17/97
2.1.7 Adjusting velocity thresholds
Open an A-Scope or a PPI for radial velocity (V) and observe the effects of the following parameter.
2.1.7.1 SQI Threshold Parameter
The SQI threshold parameter can be adjusted from 0 to 1. 0 is a signal, containing only noise, whereas 1
is a „pure“ tone signal. Typically this threshold is set to 0.4..0.5, depending on the signal quality.
The figure above shows the calculated signal quality index SQI over time. The data where acquired from
a radar receiver I/Q baseband output (only noise). When setting a SQI threshold of 0.5 and enabling V
threshold flag for SQI, most velocity speckles will be removed.
● Select 0.0 for SQI threshold parameter.
GAMIC Proprietary
Illustration 10: SQI A-Scope