Chapter 4 SPAN Operation
CPT7 and CPT7700 Installation and Operation User Manual v12
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RANGEB ONTIME 1
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RAWEPHEMB ONCHANGED
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GLOEPHEMERISB ONCHANGED (if using GLONASS)
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GALFNAVEPHEMERIS ONCHANGED (if using Galileo)
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GALINAVEPHEMERIS ONCHANGED (if using Galileo)
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BDSEPHEMERIS ONCHANGED (if using BeiDou)
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QZSSEPHEMERISB ONCHANGED (is using QZSS)
From a rover:
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RANGEB ONTIME 1
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RAWEPHEMB ONCHANGED
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GLOEPHEMERISB ONCHANGED (if using GLONASS)
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GALFNAVEPHEMERIS ONCHANGED (if using Galileo)
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GALINAVEPHEMERIS ONCHANGED (if using Galileo)
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BDSEPHEMERIS ONCHANGED (if using BeiDou)
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QZSSEPHEMERISB ONCHANGED (is using QZSS)
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INSCONFIGB ONCHANGED
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RAWIMUSXB ONNEW
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HEADING2B ONNEW (if using ALIGN dual antenna solution)
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DMICONFIGB ONCHANGED (if using a DMI sensor)
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RAWDMI ONNEW (if using a DMI sensor)
Post processing is performed using Waypoint Inertial Explorer. Visit our web site at
novatel.com/products/waypoint-software
for details.
The highest rate that you should request GNSS logs (RANGE, BESTPOS, RTKPOS, PSRPOS, and
so on) while in INS operation is 5 Hz. If the receiver is not running INS (no IMU is attached), GNSS
logs can be requested at rates up to 20 Hz.
4.10 Variable Lever Arm
The variable lever arm concept arose to support applications in which the IMU is no longer rigidly fixed to the
vehicle, but rather on a gimballed mount. This creates an issue where the input lever arm offsets to the GNSS
antenna are no longer correct, because the IMU can rotate on its mount, while the antenna remains fixed.
The use of the variable lever arm functionality requires that the device to which the IMU is attached be able to
send its gimbal rotation angles back to SPAN. These angles are used to recalculate the lever arm at the rate
that they are received. SPAN will also be able to output a gimballed solution at the rate the gimbal angles are
received.
4.10.1 Reference Frame Description
There are several frames of reference involved when dealing with a gimballed mount. The frames are all very
similar, but can be quite confusing due to small differences. Below are all frames applicable to the
implementation of the variable lever arm:
