Processing Settings

Select a workflow then click Processing Settings to access advanced customization settings. In addition to the General and Output tabs, an additional tab specific to the selected workflow may be available.

General

General Processing Settings

Field	Data
Advanced feature matching	Enabling this stage of SLAM processing can improve results in most environments, but disabling it may provide better results in complex or repeating environments.
Exclusion Zones	You can use this setting to exclude points close to Hovermap that may interfere with the SLAM algorithm or add noise to the point cloud (for example, those created by Hovermap itself, a drone, vehicle, or operator). We recommend that you use the default setting. Mode: Bounding Box: This option allows you to configure the minimum and maximum distance on each axis. X Min / Forward: Points within this minimum distance at the front of Hovermap are not processed. Default setting: 1.5 m X Max / Backwards: Points within this maximum distance at the back of Hovermap are not processed. Default setting: 1.5 m Y Min / Left: Points within this minimum distance to the left of Hovermap are not processed. Default setting: 1.5 m Y Max / Right: Points within this maximum distance to the right of Hovermap are not processed. Default setting: 1.5 m Z Min / Down: Points within this minimum distance underneath Hovermap are not processed. Default setting: 1.5 m Z Max / UP: Points within this maximum distance on top of Hovermap are not processed. Default setting: 1.5 m
Trim Data	Use this setting to specify the time (in seconds) to ignore data from either end of your dataset. This can be useful, for example, if your scan gets off to a difficult start. Start Delay: The number of seconds to be dismissed from the beginning of the scan. End Cutoff: The number of seconds to be dismissed from the end of the scan (working backward).
Georeferencing	Georeferencing Mode: Select the method used to obtain location data for accurately referencing the point cloud in real-world coordinates. Drone RTK / Vehicle RTK / Backpack RTK: Select the device used to capture the scan data. GPS: Use standard GPS data without real-time correction through RTK. This could still provide reasonably accurate georeferencing but might not achieve the same level of precision as RTK.
	OGC WKT Standard: Select the Well-Known Text (WKT) format, which is used to represent coordinate reference systems and transformations. WKT provides a standardized way to describe spatial reference systems in a textual format. WKT1: The original version of the Well-Known Text format. It describes coordinate reference systems and coordinate transformations in a textual representation and is widely used in various geospatial applications. WKT2.2018: An updated version of the Well-Known Text standard released in 2018. This version includes improvements, additional functionalities, and other updates. GNSS receiver type: The GNSS receiver used to capture the RTK data. For optimal results, ensure that the Georeferencing mode and GNSS receiver type match the hardware used during data collection. While the resulting point cloud remains usable, the accuracy may be compromised.
Base coordinate reference system	Select the CRS in which the data was originally collected. This information is essential for accurate transformations and reprojections to the target CRS.
Reprojection	Toggle on to reproject the point cloud being processed. Horizontal: Reproject to a different map projection or coordinate system. Vertical: Convert from ellipsoidal height to orthometric height using a GEOID model.
Point Filtering	You can integrate automated filtering into the processing workflow by enabling any of the following noise filters. This may eliminate the need for a separate filtering step after processing. Note that only default settings are used, there are no options to adjust the filtering parameters. STX Noise Filtering: Filters out stray points by analyzing the range, intensity, and number of LiDAR points returned. Keep in mind that this process only applies to data collected from a Hovermap ST-X and will not have any effect on point cloud data gathered from other Hovermaps. Adaptive SOR: Removes points that seem fuzzier than nearby points such as noise thickness from walls and floors. Nearest neighbor: The number of point neighbors used for evaluation. A lower setting will result in quicker processing times but removes less sparse noise. Alpha: Threshold for noise filtering. A lower setting will result in more aggressive filtering. Denoise SOR: : Removes outlier point which are less likely to be real such as reflections. Nearest neighbor: The number of point neighbors used for evaluation. A lower setting will result in quicker processing times but removes less sparse noise. Log scale: Threshold for noise filtering. A lower setting will result in more aggressive filtering.
	Moving object filtering: Removes moving points over 5 second intervals and keeps fixed point in the environment. Motion level: Detects movement over 5 second intervals. The higher the value, the lesser moving points are selected. Distance: The maximum distance for recovering fixed points. The higher the value, the more points are selected. A value of 1 to 2 cm are recommended for most scans.
	Surface Noise Reduction: Applies a smoothing filter to the point cloud, reducing noise and increasing point cloud precision. Processing time will vary per selection level. Low: Best for dense scans (for example indoors). Results in fast processing and low corner rounding. Medium: Ideal for semi dense scans. May improve results in areas with lower point density. High: Best for sparse scans (for example outdoors). Results in slower processing and higher corner rounding.
	Limit Corner Rounding: Reduces rounding of corners when point noise reduction is applied. Corners may have more noise when limit corner rounding is turned on.
	Intensity: Set the minimum and maximum intensity values of points to be written to the output point cloud. Range: Set the minimum and maximum range values of points to be written to the output point cloud.
Reset to Default	Reset all settings to the default.
Advanced The advanced settings contain additional processing parameters that can be adjusted to improve the output of the SLAM algorithm in certain circumstances. You should only use these settings when you are unable to achieve a quality output using the standard processing profiles. We recommend that you only use these settings after talking to Customer Support.
Local mapping
Time Window (Auto SLAM)	Time Window Sliding Size in Seconds: The length of the sliding window when running the optimization part of the SLAM process. Increase this value to improve the chance of a good output when there are a low number of geometric features in the scan. Increasing this number comes at the cost of increasing the processing time. Default setting: 5 seconds Time Window Sliding Shift in Seconds: Indicates how far the above window is shifted in each optimization loop. Decrease this value to improve the chance of a good output when there are a low number of geometric features in the scan. Decreasing this number comes at the cost of increasing the processing time. Default setting: 1 second Auto SLAM dynamically adjusts the Time Window processing parameters in real time when encountering challenging environments, such as tunnels, culverts, or expansive open areas with minimal geometric features. The parameter values configured in the user interface serve as optimal-case constraints; Auto SLAM will only exceed these thresholds when required to maintain tracking performance. This feature eliminates the need for manual intervention in most cases, such as switching to the "Low Feature" profile or modifying time window settings.
Point Filtering	Intensity: Set the minimum and maximum intensity values of points to be written to the output point cloud. The defaults have been chosen to ensure that noise points from the sun are excluded. We recommend that you use the default settings. Min default setting: 0 Max default setting: 255 Range: Set the minimum and maximum range values of points to be written to the output point cloud. The default values include all points out to the maximum range of the LiDAR. Min default setting: 0 Max default setting: 300
Iterations	Local Iterations: The maximum number of iterations that the main optimization loop performs during local mapping. Use this when you want to reduce local slips. Increasing this number will cause processing to take longer. Default setting: 5 Local Iterations Internal: The maximum number of iterations that the internal optimization loop performs during local mapping. Use this when you want to reduce local slips. Increasing this number will cause processing to take longer. Default setting: 5
Voxels	Voxels Size: The lowest size of voxel used to generate surfels in SLAM. Use this inside smooth tunnels/bores, as most of the information within the points will be in the subtle variations in the surface direction that occur in relatively small dimensions. Increasing this number can significantly increase processing time. Default setting: 0.4 m Voxel Levels: The number of levels used to generate surfels in SLAM. Each level is twice the size of the previous level. Use this inside tunnels/bores, as most of the information within the points will be in subtle variations in the surface direction that occur in relatively small dimensions. Default setting: 5 Voxel Minimum Points: The minimum number of points in a voxel to use for SLAM. Use this to reduce the impact of noisy data on SLAM, or to ensure that features with a low number of points are included in environments with few geometric features. Default setting: 8
Global registration
Point Filtering	Intensity: Set the minimum and maximum intensity values of points to be written to the output point cloud. The defaults have been chosen to ensure that noise points from the sun are excluded. To include all points, use the default settings. Min default setting: 0 Max default setting: 255 Range: Set the minimum and maximum range values of points to be written to the output point cloud. The default values include all points out to the maximum range of the LiDAR. Min default setting: 0 Max default setting: 300
Iterations	Global Iterations: The number of loops performed as part of the global registration process. Use this to reduce global slips. Increasing this number increases the likelihood of a quality output, but it will significantly increase processing time. Default setting: 10 Global Iterations Internal: The minimum number of iterations required to complete SLAM.
Voxels	Voxel Size: The lowest size of voxel used to generate surfels in SLAM. Use this inside smooth tunnels/bores, as most of the information within the points will be in the subtle variations in the surface direction that occur in relatively small dimensions. Increasing this number can significantly increase processing time. Default setting: 0.4 m Voxel Levels: The number of levels used to generate surfels in SLAM. Each level is twice the size of the previous level. Use this inside tunnels/bores, as most of the information within the points will be in subtle variations in the surface direction that occur in relatively small dimensions. Default setting: 5 Voxel Minimum Points: The minimum number of points in a voxel to use for SLAM. Use this to reduce the impact of noisy data on SLAM, or to ensure that features with a low number of points are included in environments with few geometric features. Default setting: 100
Velocity	Local Linear Velocity Confidence: Allows you to decide how much confidence the global registration stage should place in the linear velocity results of the local mapping stage. The number is measured in standard deviation/error, so the higher the number, the lower the confidence. This is useful, for example, for long driving scans (over 500 m), where the start and end of the scan should overlap, but do not do so cleanly, or where there are sharp changes in the trajectory that are inconsistent with the actual scan. Significantly decreasing these values can help to keep the trajectory from being snapped to the correct global slips. Default setting: 0.5
	Local Angular Velocity Confidence: Allows you to decide how much confidence the global registration stage should place in the angular velocity results of the local mapping stage. The number is measured in standard deviation/error, so the higher the number, the lower the confidence. Default setting: 0.8
Matching	Number of Matches: Set the number of voxel matches that the SLAM algorithm will search for within the given restrictions. Increase this value to make the global registration more aggressive in searching for matching voxels and then adjusting the trajectory to make similar areas overlap. This is useful for long driving scans, where increasing the number of global iterations fails to get the start and end of the scan to align. Increasing these values usually requires decreasing the Local linear Velocity Confidence and the Local Angular Velocity Confidence values. Default setting: 5 Max Distance: The maximum distance (in voxel units) that the SLAM algorithm will search for voxel matches. Increase this value to make the global registration more aggressive in searching for matching voxels and then adjusting the trajectory to make similar areas overlap. Default setting: 10

GCP

GCP Processing Settings

Field	Data
Wait for GCP Target Manual Review	Select this checkbox to pause the software while the targets are confirmed. If unselected, Emesent Aura will assume that the constellation of detected targets has been successfully matched to the survey points provided.
Point Filtering	Intensity: The filter intensities should be between 150 and 255, assuming no change to the target material.
Detection	These parameters help to identify a target. Number of Points: The minimum number of points required before a cluster (in the global and local stage) can be considered a target. Target Thickness: The maximum thickness of the cluster of points representing the target. Target Standard Deviation: Specifies target thickness. It helps to detect and identify targets more accurately. As this number increases, GCPs will be more easily detected. Default setting: 0.003 m (3 mm)
Reset to Default	Reset all settings to the default.

Merge

Merge Processing Settings

Field	Data
Voxels	Voxels Size: The lowest size of voxel used to generate surfels in SLAM. Use this inside smooth tunnels/bores, as most of the information within the points will be in the subtle variations in the surface direction that occur in relatively small dimensions. Increasing this number can significantly increase processing time. Default setting: 0.4 m Voxel Levels: The number of levels used to generate surfels in SLAM. Each level is twice the size of the previous level. Use this inside tunnels/bores, as most of the information within the points will be in subtle variations in the surface direction that occur in relatively small dimensions. Default setting: 5 Voxel Minimum Points: The minimum number of points in a voxel to use for SLAM. Use this to reduce the impact of noisy data on SLAM, or to ensure that features with a low number of points are included in environments with few geometric features. Default setting: 8
Matching	Number of Matches: Number of surfels to look for matches during SLAM. Max Distance: Maximum distance (in voxels) to search for surfel matches.
Georeferencing	Georeferencing Mode: Select the method used to obtain location data for accurately referencing the point cloud in real-world coordinates. Drone RTK / Vehicle RTK: A satellite navigation technique used to enhance the precision of position data obtained from GPS (Global Positioning System). It relies on a fixed base station and a mobile receiver. The base station precisely knows its location and communicates correction signals to the mobile receiver. Select this mode to allow the point cloud data to be aligned and referenced using highly accurate, real-time corrected GPS signals obtained through RTK technology. GPS: A satellite-based navigation system that provides location and time information anywhere on Earth. Choosing GPS as the Georeferencing Mode might mean that the software will use standard GPS data without real-time correction through RTK. This could still provide reasonably accurate georeferencing but might not achieve the same level of precision as RTK. OGC WKT Standard: Select the Well-Known Text (WKT) format, which is used to represent coordinate reference systems and transformations. WKT provides a standardized way to describe spatial reference systems in a textual format. WKT1 is recommended for best compatibility. WKT1: The original version of the Well-Known Text format. It describes coordinate reference systems and coordinate transformations in a textual representation and is widely used in various geospatial applications. WKT2.2018: An updated version of the Well-Known Text standard released in 2018. This version includes improvements, additional functionalities, and other updates.
	For PLY and trajectory files in UTM or WGS84 coordinates, an additional PRJ file containing the projection information in OGC WKT format is written. LAS files contain the projection information in the file header. If there is no GPS data recorded by Hovermap in the dataset, the output will only be in local coordinates, with the origin at the start of the scan.
Reset to Default	Reset all settings to the default.

Colorize

Colorize Process Settings

Field	Data
Video Time Range	Sets the start and end time when frames are extracted from the video. The time represents the elapsed video time, not the number of seconds to trim from the end of the total video duration. Setting the Video end time to 0 will include everything after the start time.
Frame extract interval	Uses the maximum time, distance, and angle to determine the number of video frames to skip between image extractions, keeping only the necessary images. Time: We recommended this setting is turned off to avoid repetitive extractions when the camera is not moving. The recommended range is between 1 to 20. Distance: Extracts images based on the distance the camera travels to avoid repetitive images when standing still. The recommended settings are 1 to 2 for small, confined spaces and 5 to 10 for moving capture in open spaces. Angle: Extracts images based on changes to the camera angle. The recommended settings are 10 to 15 degrees when using a perspective camera and 45 to 90 degrees when using a 360 camera.
Processing Quality	Point Color Radius: Adjusts the occlusion size of the points for colorization. A smaller value may cause color of foreground objects to bleed onto background points, larger values may result in background points that are near foreground points not to get colored. The recommended range is between 0.01 and 0.03. Visibility Voxel Size: Determines the resolution of 3D pixels (in meters). A lower setting results in finer colorization quality and increased processing time. The recommended range is between 0.01 and 0.1. Colorization Distance: Adjusts the maximum distance of points from the GoPro camera to be colorized. A higher setting results in more points being colorized and increased processing time. The recommended range is between 10 and 300.
Reduce blue sky bleeding	Allows you to reduce and mask out the color bleed or the blending of blue or gray sky on buildings and other objects. Strength: Adjust the intensity of the filter to mask the blue or gray sky. Use the Low setting for clear blue skies. For gray overcast conditions or scenes with complex features like trees, varying colors, or cloud patterns, a Medium to High setting is recommended. Note that higher strength settings may increase the likelihood of masking light-colored buildings. Alternatively, toggle on the Advanced option and configure the following: RGB blue: Set the minimum value of the blue channel to detect blue sky. A value of 200 is recommended for most sky types, 120 for blue skies with light-colored buildings, and 150 for low-light conditions such as dawn and dusk. Gray intensity: Used to detect gray sky. A value of 0 is ideal for blue skies, 20 for overcast (gray skies), and 50 for darker gray clouds. Higher values may result in unintentional masking of gray or light-colored buildings. Color detection: Identifies and masks colors with the specified RGB values. Use a setting of 25 for detecting gray skies, 35 for blue or light blue skies, 50 for blue skies with trees, and 75 for gray clouds with trees. Note that higher values may lead to unintentional masking of gray or light-colored buildings.
	When reviewing the frames between extraction and colorization, you should see the sky effectively masked in most frames. Some frames might still show minor visible patches of sky or unintended masking of building parts, but this should not impact the final colorized point cloud significantly if these issues occur only occasionally. In cases like these, it is generally better to increase the filter strength rather than decrease it, as remaining bits of visible sky are more likely to be noticeable in the final point cloud than a few mistakenly masked building parts, especially if the building is clearly visible in other frames.
Image Masking	This allows you to hide unwanted features from all your extracted frames. Choose from the available mask templates depending on the accessory/platform you are using. To create your own, Refer to the Creating a custom masksection for instructions.
Output	Remove Uncolored Points: This allows you to include or exclude points from the original scan that could not be colorized. Default setting: Unselected Keep Frame Images: This allows you to keep or remove the GoPro image frames from the colorization output folder. Select this option to use image frames and pose data in third-party software. De-select this option to save hard drive space. Default setting: Selected
Advanced	Ignore Validation Errors: Ignore any errors that are detected during input data validation. Only use this if you are sure that your inputs are correct as it may lead to failed or unusable results.
Reset to Default	Reset all settings to the default.

Extract 360 Images

Extract 360 Images Processing Settings

Field	Data
Video Time Range	Sets the start and end time when frames are extracted from the video. The time represents the actual elapsed video time, not the number of seconds to trim from the end of the total video duration. Setting the Video end time to 0 will include everything after the start time.
Frame extract interval	Uses the maximum time, distance, and angle to determine the number of video frames to skip between image extractions, keeping only the necessary images. Time: It is recommended to turn this setting off to avoid repetitive extractions when the camera is not moving. The recommended range is between 1 to 20. Distance: Extracts images based on the distance the camera travels to avoid repetitive images when standing still. The recommended settings are 1 to 2 for small, confined spaces and 5 to 10 for moving capture in open spaces. Angle: Extracts images based on changes to the camera angle. The recommended settings are 10 to 15 degrees when using a perspective camera and 45 to 90 degrees when using a 360 camera.
Camera orientation override	Allows you to configure the camera’s orientation settings manually. Roll: Configure the rotation around the front-to-back axis. Pitch: Configure the rotation around the side-to-side axis. Yaw: Configure the rotation around the side axis.
Image Masking	This allows you to hide unwanted features from all your extracted frames. Choose from the available mask templates depending on the accessory/platform you are using. To create your own, Refer to the Creating a Custom Mask section for instructions.

Output

Output Processing Settings

Field	Data
Point Cloud - output file types	PointCloud LAZ (1.4): Output a point cloud in compressed LAS 1.4 format Default: On PointCloud LAS (1.4): Output a point cloud in uncompressed LAS 1.4 format. Default: Off E57: Output a point cloud in an E57 format. Default: Off PointCloud LAZ (1.2): Output a point cloud in compressed LAS 1.2 format. Default: Off PointCloud LAS (1.2): Output a point cloud in uncompressed LAS 1.2 format. Default: Off PLY: Output a point cloud in PLY format. You can select more than one option.
Subsampling	Subsample Point Clouds: Generate a subsampled point cloud for each of the selected options above. Default: On Subsample Factor: The fraction of the points in the point cloud to sample. For example, 0.10 will output 10% of the points. Default: 0.10
Reset to Default	Reset all settings to the default.