# lidar_gnss_mapping

**Repository Path**: hyyrobot/lidar_gnss_mapping

## Basic Information

- **Project Name**: lidar_gnss_mapping
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-02-19
- **Last Updated**: 2021-02-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# LiDAR GNSS mapping 
## Framework
![image](https://github.com/ZhuangYanDLUT/lidar_gnss_mapping/blob/master/lidar_gnss_mapping/imgs/framework.png)  
The overall system framework for large-scale 3D map building in partially GNSS-denied scenes, which consists of two operating modes: `LiDAR-only mode` and `GNSS-LiDAR  mode`. While working in GNSS-denied scenes, LiDAR odometry runs with high frequency and outputs estimations with local registration errors, and LiDAR mapping provides more accurate pose estimations with low frequency.  
While moving from GNSS-denied scenes to open scenes, 3D-M-Box is working in `GNSS-LiDAR mode`. The auto coordinate alignment algorithm is applied to align the coordinate system between LiDAR and GNSS by registering a group of poses obtained from LiDAR mapping and GNSS within a certain time window. Finally, GNSS-constrained LiDAR mapping outputs the pose and point clouds with high accuracy.  
## Sample map
![image](https://github.com/ZhuangYanDLUT/lidar_gnss_mapping/blob/master/lidar_gnss_mapping/imgs/Campus3.png)  
The picture shows that 3D-M-Box can accomplish online pose estimation and map building in GNSS-denied scenes.  
## Dependency  
**ROS** (tested with kinetic)  
**gtsam** (Georgia Tech Smoothing and Mapping library, 4.0.0-alpha2)  
```
wget -O ~/Downloads/gtsam.zip https://github.com/borglab/gtsam/archive/4.0.0-alpha2.zip   
cd ~/Downloads/ && unzip gtsam.zip -d ~/Downloads/    
mkdir build && cd build    
cmake ..   
sudo make install    
```
## How to build with catkin    
```
cd ~/catkin_ws/src  
git clone https://github.com/ZhuangYanDLUT/lidar_gnss_mapping.git  
cd ~/catkin_ws  
catkin_make  
```
## Running
`roslaunch lidar_gnss_mapping lidar_gnss_mapping.launch`  
In second terminal play sample data from [test.bag](https://pan.baidu.com/s/1KUwSCFyufw5symvmWUorYA) (the access code is `ri4b`)  
`rosbag play -s 35 test.bag`