RoyalTek RBT-1000 User Manual
Page 46
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Degraded Mode:
It is the operation mode that uses 2 SVs or 1 SV for positioning output. The
effect of degraded mode in GPS receiver is to have more position fix than none
of it. It would sometimes have the situation of position drifting when this mode
is enabled.
Elevation Mask:
GPS satellites that are low on the horizon are subject to noise due to the amount of
atmosphere that the signal must travel through. Better position accuracy is often
achieved if lower elevation satellites are not used in the position solution. The
elevation mask is used to exclude the use of satellites in the position solution that
are below a defined elevation mask.
DOP Mask:
DOP is the abbreviation of “dilution of precision”. To achieve a positioning
accuracy of 10m, it must combine the ranging accuracy and geometry to be
acceptable values. GDOP is geometric dilution of precision which contains the
effect of position (x, y, z) and time. PDOP is the position dilution of precision
which contains the effect of position (x, y, z). HDOP is the horizontal dilution
of precision which contains the effect of horizontal plane (x, y). Better position
accuracy is often achieved with smaller DOP value. The DOP Mask is used to
exclude the output of position that DOP value is higher than the DOP Mask.
SBAS Mode:
SBAS is abbreviation of
Satellite-Based Augmentation Systems. It is WAAS in US,
European Geostationary Navigation Overlay Service (EGNOS) in Europe and
Multi-functional Transport Satellite (MTSAT) Satellite -based Augmentation System
(MSAS) in Japan. It provides additional ranging capability, integrity information, and
differential corrections at L1 frequency, which is broadcast from geostationary
satellites.