The SHOALS-1000T includes an embedded Applanix POS AV 410, which
measures orientation (roll, pitch and heading). The system consists
of a POS AV computer with a NovAtel Millennium GPS card, an Inertial
Measuring Unit (IMU), and one NovAtel 512 airborne L1/L2 GPS antenna.
The IMU is permanently mounted within the SHOALS-1000T
sensor. It uses a series of linear accelerometers and angular
rate sensors that work in tandem to determine orientation.
The orientation information is used in post-processing
to determine position of the laser spots. However, analog data from
the POS AV are also used during acquisition to maintain a consistent
laser scan pattern.
Applanix POS AV 410 specification sheet