The Signal Filter parameter GPS, within the Advanced Settings, configures the use of the software through which the system GeoNave decides whether the GNSS whether or not he is fit for the job, based on his current quality. When the filter is Able, if the value of HDOP is less than 2.0, the signal is considered OK; otherwise, the GNSS will be cut. With the filter Disabled, the value of HDOP is not considered.
The Signal Filter GPS should be used when the user does not want the system to operate with poor quality reception of the GNSS, for example in the vicinity of riparian forest, so as not to affect the accuracy of the application.

The Signal Filter configuration screen GPS is shown in the figure below.