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APN-078: Configuring SPAN for
Hydrographic Applications in OEM7
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Table of Contents
1 Overview ....................................................................................................................... 3
2 ALIGN Calibration ......................................................................................................... 4
2.1 ALIGN Calibration Procedure ........................................................................................ 5
4. SPAN Configuration for Hydrographic Acquisition ................................................................... 7
4.1 MBES Configuration ........................................................................................................... 7
4.2 SPAN integration with Hydrographic Acquisition Systems .................................................. 7
4.2.1 Recommended SPAN Configuration for HYPACK/HYSWEEP .........................................................7
4.2.2 Recommended SPAN Configuration for QPS QINSy: .....................................................................8
4.2.3 Recommended SPAN Configuration for Kongsberg SIS .................................................................9
4.2.4. Recommended SPAN Configuration for EIVA NaviScan ...............................................................9
4.2.5 Recommended SPAN Configuration for PDS2000 ...................................................................... 10
5. Post-processed Data from Waypoint Inertial Explorer ............................................................ 10
Final Points ............................................................................................................................... 11
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Marine SPAN
1 Overview
This application note provides an overview of NovAtel’s SPAN Marine functionality for use in the
hydrographic industry. It is part of the SPAN released firmware in OEM7.
- ALIGN calibration: calibrates heading offset between SPAN computation frame and the dual
antenna baseline
- EM3000 message output: for SPAN use with Kongsberg SIS
- Remote Heave: Remote heave applied when offsetting INS through the INSOFFSET command
- Added Heave field to PASHR: PASHR log now includes heave in field 7
- KVH1750 pulse width adjustment and accelerometer offset: Takes into consideration latest KVH
hardware updates to KVH IMUs
- Improved bias estimation during initialization
The application note will also go through what SPAN configuration is required for use with the following
hydrographic acquisition software:
- HYPACK/HYSWEEP
- QPS QINSy
- Kongsberg SIS
- Eiva NaviScan
- Reson PDS2000
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2 ALIGN Calibration
A dual antenna SPAN solution is required to have the best possible INS solution in a
hydrographic/marine (i.e: low dynamics) environment. The dual antenna baseline can be pointing
anywhere with respect to the IMU body frame as long as the angular misalignment between the GNSS
baseline and the IMU body frame is accurately known. The ALIGN (boresight) calibration computes
this fixed offset, greatly reducing the initial kinematics that are normally required to converge INS
attitude.
Please note the ALIGN calibration should only have to be done once per installation. Even though the
values are going to be stored in NVM, it is good survey practice to write the value in case it is cleared
by mistake.
Also, please note the angular misalignment between the sonar head and the IMU body frame is taken
into account through a patch test.
A
Figure 2-1: BORESIGHT calibration
- The two red circles represent the master and rover antennas, with the GNSS heading being
computed from the master to the rover.
- The blue box represents the IMU with the axes representing the SPAN computation frame. Note
that if the Z-axis of the IMU enclosure isn`t pointing towards zenith, there will be a mismatch
between the IMU enclosure frame and the SPAN computation frame. See SPAN on OEM7 User
Manual for further information.
- The brown line represents the keel.
- β is the heading offset between the SPAN computation frame and the dual antenna baseline. This
value is computed in the ALIGN calibration.
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2.1 ALIGN Calibration Procedure
1. Create a text files with commands that specify IMU orientation, IMU type, and lever arms
between the IMU centre of navigation and both antennas.
NOTE: only the primary antenna is required to be known with high accuracy. The secondary
antenna lever arm is only used to compute an initial boresight angle which will be further
calibrated in this procedure.
In the following example, the IMU is an LN200 setup in the default way (z-axis pointing upwards,
Y-axis pointing forward) with the lever arms measuring the distance separation between the IMU
centre of navigation and each antenna. Modify the values shown in red accordingly to match your
setup.
CONNECTIMU COM1 LN200
SETINSROTATION RBV 0 0 0
SETINSTRANSLATION ANT1 0.8 -0.30 1.45 0.05 0.05 0.05
SETNINSTRANSLATION ANT2 -0.8 -0.30 1.45 0.05 0.05 0.05
2. Once you have a clear view of the sky and the SPAN system is powered on, copy/paste each of the
commands from step 1 into the Console Window in NovAtel Connect. The INS should align within
a few seconds through the aided-transfer INS alignment method (i.e: dual GNSS antenna).
3. Apply motion in order to converge INS error estimates
Apply figure 8 motion until the INS solution status has changed from
INS_ALIGNMENT_COMPLETE to INS_SOLUTION_GOOD.
4. Send the following command: LOG INSCALSTATUS ONCHANGED
The command above will output the INSOFFSETS message which can be used to monitor the
status of the ALIGN (boresight) calibration.
5. Send the following command to start the ALIGN calibration:
INSCALIBRATE ALIGN NEW < StdDev>
Where < StdDev> represents the standard deviation (in degrees) at which the ALIGN calibration
can stop. Suggested value is 0.3 degrees. The smaller the standard deviation value, the longer the
calibration. Recall the boresight calibration computes the angle between the SPAN computation
frame and the dual antenna baseline.
6. You should now notice the INSCALSTATUS message is output indicating the start of the ALIGN
calibration. If the INS hasn’t been converged enough (i.e: more initial kinematics are required),
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the INSCALSTATUS would read INS_CONVERGING. This status means the calibration process
is on hold until the INS solution is fully converged. Otherwise, the status will read
CALIBRATING.
7. Move forward in a straight line while the boresight calibration is monitored through the
INSCALSTATUS message.
The direction of the waves does not matter. The ALIGN calibration compares ALIGN and the INS
heading to calibrate the best possible offset between both.
8. The INSCALSTATUS should report CALIBRATED once the ALIGN calibration is complete.
NOTE: The standard deviation threshold input during the ALIGN calibration initialization is not the
only condition used to assess the completion of the calibration. Residuals of the corrections are also
monitored which might lead to final values that have better standard deviation values than what was
specified via command.
9. Write down the rotations (along with their respective standard deviations) around X, Y, Z reported
at the end of INSCALSTATUS. In the following example, the values are shown in bold:
[COM1]INSCALSTATUS COM1 0 80.0 FINESTEERING 1880 317815.012 02000000 a4f2 32768
< ALIGN 90.2516 0.0000 0.0000 0.2561 0.0000 0.0000 CALIBRATED 0
10. Comment out the secondary lever arm (SETINSTRANSLATION ANT2) from the batch file from
step 1. This can be done by adding a ‘;’ character at the start of the line in the batch file.
11. Add the following line to the batch file used for unit configuration.
SETINSROTATION ALIGN <xRotALIGNCal> <yRotALIGNCal> <zRotALIGNCal>
<xStdDev> <yStdDev> <zStdDev>
where:
- xRotALIGNCal = INSCALSTATUS calibration about IMU body’s x-axis
- yRotALIGNCal = INSCALSTATUS calibration about IMU body’s y-axis
- zRotALIGNCal = INSCALSTATUS calibration about IMU body’s z-axis
- xStdDev = INSCALSTATUS calibration standard deviation about IMU body’s x-axis
- yStdDev = INSCALSTATUS calibration standard deviation about IMU body’s y-axis
- zStdDev = INSCALSTATUS calibration standard deviation about IMU body’s z-axis
12. Reset receiver and send the modified batch file.
13. Send SAVECONFIG to the receiver to save the SPAN configuration in NVM.
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4. SPAN Configuration for Hydrographic Acquisition
SPAN requires to send data to:
MBES: for timing and motion stabilization/compensation
Hydrographic acquisition system: Only EIVA and HYPACK support NovAtel binary messages.
All other acquisition systems require NMEA or NovAtel ASCII logs.
4.1 MBES Configuration
Attitude has to be sent to multibeam transducers able to apply real-time motion stabilization/compensation
(e.g. R2Sonic). Depending on the setup, it might also be required to send timing messages such as GPZDA
although this is usually handled in the acquisition software side of things.
4.2 SPAN integration with Hydrographic Acquisition Systems
The following are the suggested messages to be output for each of the following hydrographic acquisition
software:
4.2.1 Recommended SPAN Configuration for HYPACK/HYSWEEP
NovAtel Log
Recommended Input
Reason
TSS1
ONTIME 0.02
For real-time motion
stabilization and
compensation
GPZDA
ONTIME 1
For accurate timing
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The following messages need to be logged in both HYPACK and HYSWEEP. HYPACK supports the
binary version of the command (`B` appended at end) whereas HYSWEEP only supports the ASCII
version of the commands (`A` appended at end).
It is suggested to use one ICOM port for HYPACK and a different one for HYSWEEP. This way you have
two ports over one physical connection (e.g: ICOM1 for HYPACK, ICOM2 for HYSWEEP).
NovAtel Log for
HYSWEEP
Recommended Input
Description
INSPVAA
ONTIME 0.02
Lat, long, ellipsoidal height, roll, pitch,
heading
HEAVEA
ONNEW
Heave
BESTPOSA
ONTIME 0.2
Best Position (lat, long, ellipsoidal
height, geoidal height)
TIMEA
ONTIME 1
UTC time
4.2.2 Recommended SPAN Configuration for QPS QINSy:
NovAtel Log
Recommended Input
Description
INSPVAA
ONTIME 0.02
Lat, long, ellipsoidal height, roll, pitch, heading
HEAVEA
ONNEW
Heave
BESTPOSA
ONTIME 1
Best Position (lat, long, ellipsoidal height, geoidal
height)
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TIMEA
ONTIME 1
UTC time
INSCOVA
ONTIME 1
Roll, pitch, heading covariance matrix
QINSY supports post-processed navigation and attitude in user defined ASCII formats
4.2.3 Recommended SPAN Configuration for Kongsberg SIS
NovAtel Log
Recommended Input
Description
EM3000
ONTIME 0.02
Roll, pitch, heading, heave
GPGGA
ONTIME 0.01
Lat, long, ellipsoidal height
GPZDA
ONTIME 1
For accurate timing
4.2.4. Recommended SPAN Configuration for EIVA NaviScan
NovAtel Log
Recommended Input
Description
INSPVASB
ONTIME 0.02
Lat, long, ellipsoidal height, roll, pitch,
heading
HEAVEB
ONNEW
Heave
BESTPOSB
ONTIME 0.2
Best Position (lat, long, ellipsoidal
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height, geoidal height)
TIMEB
ONTIME 1
UTC time
4.2.5 Recommended SPAN Configuration for PDS2000
NovAtel Log
Recommended Input
Description
INSATTA
ONTIME 0.01
Roll, pitch, heading
HEAVEA
ONNEW
Heave
INSPOSA
ONTIME 0.01
Lat, long, ellipsoidal height
5. Post-processed Data from Waypoint Inertial Explorer
Post-processed inertial data from Inertial Explorer can be imported into the following hydrographic
processing acquisition systems:
- CARIS HIPS/SIPS
- HYSWEEP
- QPS Qimera
- Eiva NaviEdit
The *.sbtc file is what is used in every case. This is a smoothed tightly coupled binary file containing the
post-processed position, velocity, and attitude (including heave) that gets generated when post-processing
data in Inertial Explorer. Please contact the corresponding vendor of the hydrographic post-processing
software for further information as to how to import *.sbtc files.
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Final Points
If you require any further information regarding the topics covered within this application, contact:
NovAtel Customer Service
1120 68 Ave. N.E.
Calgary, Alberta, Canada, T2E 8S5
Phone: 1-800-NOVATEL (in Canada or the U.S.) or +1-403-295-4500
Fax: 403-295-4501
E-mail: support@novatel.com
Website: www.novatel.com