MultiSpectral Processing Tutorial

Description

Processing of multispectral photos of single flight is supported in LiMapper, which is widely applied to geological disaster monitoring, surveying and mapping, forestry analysis, environmental protection, etc. Multiple bands can be processed simultaneously and exported using custom combination.

Workflow

1. Preparation

(1) New Project

• Input the project name and project path in New Project Wizard;
• Edit project template.

(2) Load Data（Single flight）

Set data type as multispectral. Photos of same band should be imported as a group. Please refer to Photo Editing.

Note：Photos in the same group shouldn't have identical names. It's not recommended to process multispectral photos of multiple flights simultaneously.

(3) Import POS (Optional)

If location informations in EXIF are not available, POS files of formats TXT or CSV can be imported. Please refer to Importing POS.

Output results are in local coordinate system if project is not georeferenced.

Note：There is no need to import POS separately for each band in principle, because different bands share the same POS in general; But import per band is still supported in case of independent bands.

(4) Set Master Band (Optional)

After data import, a custom master band is also supported if needed, please refer to Master Band Setting.

2. Processing

(1) Mosaicking

In the Process GUI below, you can check/uncheck procedures depending on need. After clicking "Configure" button, you can configure related template parameters.

Note: The dense point cloud type is only editable when creating template.

3. Export

(1) Export Point Cloud

Both Sparse and dense point cloud can be exported after processing. Supported formats are PLY, LAS, and OBJ. In addition, dense point cloud can also be exported as OSGB file. Please refer to Exporting Cloud

(2) Export DEM/DSM

Users can specify coordinate system, compress method and resolution before exporting DEM/DSM. More details can be found in Exporting DEM/DSM.

(3) Export Orthomosaic

Users can specify coordinate system, compress method and resolution before exporting Orthomosaic. More details can be found in Exporting DEM/DSM.

(4) Export Byproducts

Please refer to Exporting Camera Parameters, Exporting Undistorted Photos, Exporting Stitching Lines, Exporting Reports.

Example

The data is acquired in a town using RedEdge multispectral camera with the image size 1280*960. There are 11000 photos of 5 bands in total, 2200 photos per band.

Source Data

Example of source data

Dense Point Cloud

The dense point cloud is displayed by elevation in the software LiDAR360.

DEM

The DEM is displayed by elevation in the software LiDAR360.

Orthomosaic

The product is a pseudo-color mosaic image of bands 4,3,2.