Specifications
Operation 23
Operation
in the ideal correlation function, so it is usually almost impossible for the correlator-
base multipath integration to completely compensate for this error.
In order to completely compensate for close-in multipath, we suggest to use Choke-
ring antennas along with the Enhanced Strobe Correlation technique.
Far multipath can cause very large errors if a good multipath mitigation technique is
not used.
Far multipath occurs when there is a reflecting surface at some distance from the
antenna, such as a building, a mast, a mountain, etc. Metal surfaces cause the
strongest reflections. Far multipath signals can be very nearly eliminated by good
correlator-based multipath mitigation techniques.
Signal to Noise Ratio
The Signal to Noise ratio or C/No. as given by the receiver is the ratio of the total
signal power to the noise power in a 1 Hz bandwidth otherwise known as the Carrier
to Noise Ratio or C/No. The reference point of the reading is the antenna connector
located on the receiver’s back-panel. It is expressed in units of dB.Hz.
It is important to realize that the receiver displayed C/No. includes the degradation
caused by many factors before reaching the receiver, including: antenna gain, antenna
temperature, and LNA noise figure. The C/No. at the output of the antenna element
will be degraded by the noise produced by the first amplifier, known as the low noise
Figure 2.6: Detailed View of Multipath Mitigation Performance
0 10 20 30 40 50
-10
-8
-6
-4
-2
0
2
4
6
8
10
Multipath Delay (meters)
Tracking Error (meters)
Multipath Code Error Envelopes
Narrow Standard Correlator
Ashtech
Enhanced Strobe
Correlator