Update README.md

README.md

@@ -5,4 +5,132 @@ tags:
 - Digital_elevation_map
 - DEM
 - Terrain_navigation
----
+---
+
+# UAV Trajectory Simulation Dataset for Terrain-Based Localization
+
+## Dataset Overview
+
+This dataset contains simulated UAV flight data generated using ROS2, Gazebo, and PX4 autopilot system. The dataset features a quadcopter performing autonomous flight trajectories over realistic terrain imported from satellite imagery and Digital Elevation Model (DEM) maps of the Taif region in Saudi Arabia.
+
+## Dataset Files
+
+The dataset contains:
+- **7 trajectory CSV files**: `traj_1_taif_map_data.csv` through `traj_7_taif_map_data.csv`
+- **1 Digital Elevation Model**: `taif_DEM.tif` (GeoTIFF format)
+
+### File Structure
+```
+traj_1_taif_map_data.csv
+traj_2_taif_map_data.csv
+traj_3_taif_map_data.csv
+traj_4_taif_map_data.csv
+traj_5_taif_map_data.csv
+traj_6_taif_map_data.csv
+traj_7_taif_map_data.csv
+taif_DEM.tif
+```
+
+## Data Characteristics
+
+### Flight Telemetry Data (CSV Files)
+Each CSV file contains synchronized flight measurements with the following columns:
+
+| Column | Description | Unit |
+|--------|-------------|------|
+| `timestamp` | Unix timestamp with nanosecond precision | ns |
+| `tx`, `ty`, `tz` | 3D position coordinates in local frame | m |
+| `vel_x`, `vel_y`, `vel_z` | Linear velocities | m/s |
+| `orientation_x`, `orientation_y`, `orientation_z`, `orientation_w` | Quaternion orientation | - |
+| `angular_vel_x`, `angular_vel_y`, `angular_vel_z` | Angular velocities | rad/s |
+| `linear_acc_x`, `linear_acc_y`, `linear_acc_z` | Linear accelerations | m/s² |
+| `latitude`, `longitude` | GPS coordinates | degrees |
+| `altitude` | GPS altitude | m |
+| `lidar_range` | LiDAR distance measurement | m |
+| `AMSL` | Altitude above mean sea level | m |
+
+### Digital Elevation Model (taif_DEM.tif)
+- **Format**: GeoTIFF Digital Elevation Model
+- **Coverage**: Taif region terrain corresponding to all flight trajectories
+- **Source**: Generated from real satellite imagery and DEM data
+- **Application**: Provides terrain elevation reference for localization algorithms
+
+### Data Sample
+```
+timestamp,tx,ty,tz,vel_x,vel_y,vel_z,orientation_x,orientation_y,orientation_z,orientation_w,angular_vel_x,angular_vel_y,angular_vel_z,linear_acc_x,linear_acc_y,linear_acc_z,latitude,longitude,altitude,lidar_range,AMSL
+993.128,-251.516708374023,-45.2020683288574,213.485137939453,5.11164286075962,0.045598402309674,0.220133052308578,0.023194692263158,0.003760659242595,-0.99578133623088,0.088699054215541,0.003482932690531,0.020824493840337,0.000891029543709,-0.57949709892273,0.020221803337337,9.83791255950928,21.2853756,40.2180381,1111.32048684451,213.142578125,1105.18774414063
+```
+
+## Simulation Environment
+
+- **Flight Controller**: PX4 autopilot with realistic flight dynamics
+- **Simulator**: Gazebo physics simulation
+- **Framework**: ROS2 for data collection and sensor integration
+- **Terrain Source**: Real-world satellite imagery and elevation data from Taif region
+- **Vehicle**: Simulated quadcopter with onboard sensors
+
+## Applications
+
+This dataset is designed for research in:
+- **Inertial Navigation Systems (INS)** development and testing
+- **Terrain-based UAV localization** algorithms using elevation data
+- **GPS-aided navigation** system validation
+- **Multi-modal sensor fusion** techniques (IMU, GPS, LiDAR)
+- **Flight trajectory analysis** and planning
+- **Autonomous navigation** algorithm development
+
+## Technical Specifications
+
+### Flight Characteristics
+- **7 distinct trajectories** with varying flight patterns
+- **Precise time synchronization** across all sensor modalities
+- **6DOF pose ground truth** available for algorithm benchmarking
+- **Multi-sensor data fusion** including IMU, GPS, and LiDAR
+
+### Terrain Characteristics
+- **Desert-like terrain** with challenging navigation conditions
+- **Realistic elevation profiles** from actual geographic data
+- **Elevation-based localization** opportunities using DEM data
+
+## Limitations
+
+- **Sensor Coverage**: Current version includes IMU, GPS, and LiDAR data only
+- **Terrain Type**: Limited to desert environment characteristics
+- **Single Region**: Data collected over Taif region only
+
+## Future Dataset Versions
+
+### Planned Additions
+- **Camera Images**: Complete image sequences from onboard cameras will be uploaded in the next version
+
+## Usage Notes
+
+1. **Data Alignment**: All measurements in each CSV file are time-synchronized
+2. **Coordinate Systems**: Position data (tx, ty, tz) is in local simulation frame
+3. **Terrain Context**: Use `taif_DEM.tif` for elevation reference and terrain-based localization
+4. **Multiple Trajectories**: Each CSV represents a complete autonomous flight mission
+5. **Future Updates**: Camera images will be added in a future version of this dataset
+
+## Data Quality
+
+- **Ground Truth Accuracy**: Complete 6DOF pose information for validation
+- **Realistic Physics**: PX4 autopilot provides authentic flight dynamics
+- **Synchronized Sensors**: All data streams precisely time-aligned
+- **Validated Terrain**: Elevation model derived from verified satellite sources
+
+## Citation
+
+If you use this dataset in your research, please cite:
+```
+@article{JARRAYA2025106613,
+title = {OS-RFODG: Open-source ROS2 framework for outdoor UAV dataset generation},
+journal = {Results in Engineering},
+volume = {27},
+pages = {106613},
+year = {2025},
+issn = {2590-1230},
+doi = {https://doi.org/10.1016/j.rineng.2025.106613},
+url = {https://www.sciencedirect.com/science/article/pii/S2590123025026829},
+author = {Imen Jarraya and Mohamed Abdelkader and Khaled Gabr and Muhammad Bilal Kadri and Fatimah Alahmed and Wadii Boulila and Anis Koubaa},
+keywords = {UAV localization, Dataset generation, ROS2 framework, Geospatial mapping, Sensor data synchronization},
+```