User manual

U-See User Manual - View Menu: Real time information windows

• EXCESS: Excessive correction detected. If variation since reference was

established surpass a threshold correction is discarded as invalid. This may

be indicative of ground sensor failure. Please, contact Airelectronics for

support in this case.

• NOTSET: Barometric altimetry has been never been crossed against GPS

measurement in the current autopilot uptime. This is a typical situation

encountered when the system has been powered-on recently and has never

had a valid GPS fix. This implies that current static pressure indication may

be off by several dozen of meters until an altimeter 'set' command is

performed. For this, go to Settings → Air Data system and press the ' Sync GPS

& Altimeter' button. Valid GPS fix is necessary for this to work and the

autopilot will perform automatically a set command when it has GPS fix

calculated with at least 6 satellites.

• FILT: The Ground Control station indication of pressure have changed too fast

in a very short time and the autopilot is introducing this correction in a

filtered way to avoid sudden changes of altitude. This situation can occur

when recovering contact with an UAV after a long period of communications

blackout. Special attention is required in case this occurs.

• Position: shows data on GPS solution for current position in the UAV

• State: shows quality information regarding the fix:

◦ Mode shows what kind of solution the GPS is offering.

Possible modes are: 2D, 3D, DGPS and 'No Fix'.

◦ Satellites show the number of satellites used to produce current navigation fix

◦ Diff Age: Shows how old is the data used for Differential correction

• U-Ground Position: GPS solution for the position of the Ground Control Station.

• GPS Channel Info: you will have access to the signal status of the tracking channels

the GPS modules has. Informing you of which satellite the autopilot is tracking to

compute its GPS position and what signal level is receiving from every satellite.

The chart shows the identification of the Space Vehicle being tracked (SV ID). Those

SV identified with numbers above 120 correspond to SBAS

systems such as WAAS

or EGNOS.

The chart displays also the signal level. Acceptable signal levels would be over 30

dbHz.

2.8.2

Relative GPS Status (Optional)

This window will be only displayed on moving base operations enabled versions of U-See.

So this section may not apply to your U-See version

10 Do not mistake this number with the number of visible satellites over the horizon.

11 Satellite Based Augmentation Systems

Document Version 1.25 21