Novatel Software Version 4.45 OM-20000026 Rev 1 Marine GPS System User Manual


 
E Comparison Of RT-2 And RT-20
MiLLennium Command Descriptions Manual 207
RT-2 Performance
The RT-2 software provides the accuracies shown in Table E-3 & Figure E-1 (static mode) and Table E-4 &
Figure E-2 (kinematic mode) for “typical” multipath, ionospheric, tropospheric, and ephemeris errors, where
“typical” is described as follows:
A typical multipath environment would provide no carrier-phase double-difference multipath errors
greater than 2 cm or pseudorange double-difference multipath errors greater than 2 m on satellites at 11°
elevation or greater. For environments where there is greater multipath, please consult NovAtel Customer
Service.
Typical unmodeled ionospheric, tropospheric and ephemeris errors must be within 2σ of their average
values, at a given elevation angle and baseline length. It is assumed that the tropospheric correction is
computed with standard atmospheric parameters. All performance specifications assume that at least 6
satellites above the mask angle (varies between 11 and 14 degrees) are being tracked on both L1 and L2.
All accuracy values refer to horizontal RMS error, and are based on matched positions. The level of position
accuracy at any time will be reflected in the standard deviations output with the position.
Table E-3 RT-2 Performance: Static Mode
Table E-4 RT-2 Performance: Kinematic Mode
Baseline
length
Time since L2 lock-on with at least
6 satellites above mask angle
Horizontal accuracy at
the stated time
Runs meeting the stated
accuracy at the stated time
< 10 km 70 seconds + 1.5 sec/km 2 cm + 0.5 ppm 75.0%
< 10 km 5 minutes 1 cm + 1 ppm 75.0%
< 15 km 4 minutes 5 cm 66.7%
< 25 km 7 minutes 7 cm 66.7%
< 35 km 10 minutes 35 cm 66.7%
< 35 km 30 minutes 25 cm 66.7%
Baseline
length
Time since L2 lock-on with at least
6 satellites above mask angle
Horizontal accuracy at
the stated time
Runs meeting the stated
accuracy at the stated time
< 10 km 120 seconds + 1.5 sec/km 2 cm + 0.5 ppm 75.0%
< 15 km 8 minutes 8 cm 66.7%
< 25 km 14 minutes 10 cm 66.7%
< 35 km 20 minutes 40 cm 66.7%
< 35 km 60 minutes 25 cm 66.7%