SLAM

The SLAM window is used to initiate SLAM processing, as well as to optimize a SLAM cloud:

Manage SLAM

The Manage SLAM menu contains tools to start SLAM processing, as well as to quit, save, or re-open an existing SLAM cloud.

• Start SLAM: Used to start SLAM. The SLAM Processing Profile dialog will open upon clicking Start SLAM.

• Restore SLAM session: Used to restore a previous SLAM session (PBSTREAM file).

• Finalize and save SLAM session: Used to save a SLAM session to a PBSTREAM file. This will also create a PLP and CLOUD file associated with the SLAM session.

• Write trajectory: Writes SLAM trajectory to a POF file.

• Write positions to PVA: Writes the positions from the SLAM trajectory to a PVA update file, used in InertialExplorer.

• Quit SLAM: Quits SLAM processing. If the SLAM session has not yet been saved, it will discard the session and the SLAM cloud.

Optimization Weights

Certain parameters that control the SLAM filter are configurable on the fly, meaning that these parameters can be adjusted and the SLAM trajectory and SLAM cloud will be recomputed immediately. Restored SLAM sessions can also be recomputed and re-optimized by adjusting these settings.

• Georef. weight: This is the weight of GNSS updates in the SLAM filter. GNSS updates can come from a NAV, CG, or CTS file loaded into the project

• Georef inlier scale: The georeferencing inlier scale specifies the distance from trajectory at which GNSS measurement start having diminishing effect. This parameter can be set to a smaller distance at the very end in order to eliminate the effect of outlier measurements.

• Gravity alignment weight 1: Performs global gravity (i.e. pitch/roll) alignment of the trajectory according to the IMU measurements, while also having a "smoothing" effect on the trajectory positions. In our testing, a moderate (10-200) weight on the gravity alignment 1 has proven to work.

• Gravity alignment 2: An alternative implementation of gravity alignment 1 (albeit it should not have the "smoothing" effect).

• Corrections: This is the weight applied to user-select corrections.