Advantages of GNSS inertial integrated navigation NovAtel's SPAN technology integrates two different but complementary technologies: GNSS positioning technology and inertial navigation technology. The absolute accuracy of the GNSS positioning plus the stability of the IMU gyroscope and accelerometer measurements provides a 3D position, velocity, and attitude solution. Unlike a single GNSS navigation system, even when the GNSS signal is occluded, the result of the solution is stable and continuous.
Why Use NovAtel SPAN Technology The foundation of SPAN technology is its tightly coupled design, which provides exceptional performance and superior continuous performance when GNSS reception is limited. Tight coupling means that satellite data can still be used when GNSS positioning is invalid.
In addition, SPAN technology provides GNSS with faster signal reacquisition capabilities, with the result that more GNSS measurements are available to assist with inertial solutions. The advantage of this GNSS capture is to improve RTK performance by maintaining high-precision inertial navigation as the number of satellites decreases. The OEMV receiver itself handles all GNSS and inertial navigation data. The IMU is housed separately in a package and separated from the GNSS board to ensure a modular design. Current ProPak-V3 (RS-422) users can have their receivers process INS data performance by purchasing upgrade firmware.
Through the standard serial port, and then use a simple command and data logging interface, you can complete all settings and data collection. Once the installation of the hardware is complete, the system operation settings can be completed within minutes.
Unique advantages of the iIMAR-FSAS SPAN system The FSAS-EI-SN IMU is manufactured by the ilMAR company in Germany. The IMU employs a closed-loop technology with a gyro deviation of less than 0.75 degrees/hour and an accelerometer deviation of less than 1 mg. The IMU is triggered by the NovAtel receiver to ensure that all IMU measurements and GNSS measurements are synchronized. For commercial applications, the IMU can provide 2 months of ARO and must comply with German export regulations.
Product performance:
SPAN system performance 1
Positioning accuracy Single point L1Single point L1/L2
WAAS L1
WAAS L1/L2
DGPS
OmniSTAR
VBS
XP
HP
RT-202
RT-2
1.8 meters RMS
1.5 meters RMS
1.2 meters RMS
0.9 meter RMS
0.45 mRMS
0.7 meters
0.15 meters
0.1 meter
0.2 meters
1cm + 1ppm RMS
Speed ​​accuracy 0.02 m/s RMS
Measurement accuracy 3 Pitch roll azimuth
0.015o RMS
0.015o RMS
0.041 o RMS Acceleration Accuracy 0.03 m/s2 RMS Maximum Speed ​​4 514 m/s Maximum Height 4 18,288 m Data Refresh Rate 5 IMU Observing 200 Hz
200 Hz INS position
INS speed 200 Hz
INS Attitude 200 Hz IMU Performance IMU-FSAS-EI-SN Gyro Input Range Gyro Partial Rate Gyro Partial Speed ​​Proportional Factor Angle Random Walk Acceleration Measurement Range Accelerometer Linearity/Scale Factor Accelerometer Deviation ±500 deg/sec
< 0.75 deg/hr
300 ppm
0.1 deg/√hr
6 ±5g
400 ppm
1.0 mg IMU Physical Electrical Characteristics Volume Weight 128 x 128 x 104 mm
2.1 kg Power Consumption Power Consumption Input Voltage Input/Output Connector
16 W (maximum)
+11 to 34V
MIL-C-38999-lll, 22-pin Environmental Adaptability Index Temperature Operating Storage Humidity
MTBF (balanced no-failure time)
-40°C to +71°C
-40°C to +85°C
95% non-condensing
35,000 hours
Accuracy after GPS signal interruption Table 7
Interruption period
Positioning mode
Position error (m)
Speed ​​error (m/s)
Measurement error (degrees)
Level
vertical
Level
vertical
Roll
Pitch
course
10s
RTK
0.013
0.03
0.018
0.008
0.006
0.007
0.009
DGPS
0.30
0.28
0.026
0.006
0.007
0.009
0.024
SP
1.24
1.51
0.028
0.008
0.008
0.010
0.025
30s
RTK
0.83
0.16
0.055
0.008
0.009
0.010
0.017
DGPS
1.01
0.41
0.059
0.007
0.010
0.012
0.026
SP
1.60
1.55
0.062
0.010
0.010
0.016
0.028
60s
RTK
3.42
0.44
0.129
0.013
0.012
0.014
0.023
DGPS
3.62
0.69
0.128
0.013
0.012
0.015
0.030
SP
3.95
1.65
0.131
0.014
0.012
0.015
0.032
SPAN working principle diagram
annotation:
1. Typical value. Performance indicators may be aggravated by GPS system performance, US DOD anthropogenic interference, ionospheric and tropospheric states, satellite geometry, baseline length, multipath effects, and the presence of natural or unnatural sources of interference.
2. Expected accuracy after static convergence
3. When SPAN works in RTK mode
4. Output permission limit: height 18288 meters, speed 514 meters/second
5. If the original IMU measurement (200Hz) is recorded, the required maximum position, velocity, and attitude can be recorded at 50Hz.
6. GNSS receiver can continuously track up to 4g
7. These RMS values ​​are calculated with reference to the GPS RTK mode