DEMBuilder

Digital Elevation Model Builder for Agricultural Applications

DEMBuilder is a high-performance desktop application designed to process GPS data from agricultural operations and generate Digital Elevation Models (DEMs) optimized for precision farming and tractor guidance systems.

🚀 Features

Core Functionality

• Multi-GPS Data Processing: Handle up to 6 GPS units recording simultaneously
• Large Dataset Support: Process 600,000+ GPS points with streaming algorithms
• Real-time Progress Tracking: Visual progress bars for all operations
• Interactive Boundary Selection: Draw field boundaries on satellite maps
• High-Performance Filtering: Parallel processing with HDOP, RTK, and Age filters
• Multiple Export Formats: RgF DEM, GeoTIFF, and text file exports

Export System

• RgF DEM Format: Single-file agricultural packages optimized for ABLS software
• GeoTIFF Export: AgOpenGPS-compatible tiled exports with GDAL integration
• Text Export: ASCII grid format for general use
• Thumb Drive Optimized: Single files perfect for field transfer

Performance Features

• Parallel Processing: Multi-core CPU utilization for filtering and boundary operations
• Streaming Processing: Memory-efficient handling of massive datasets
• Spatial Indexing: Optimized point-in-polygon testing with bounding box pre-filtering
• Asynchronous Operations: Responsive UI during long-running processes

🏗️ Architecture

Application Structure

DEMBuilder/
├── MainWindow.xaml(.cs)      # Main application window with wizard navigation
├── Pages/                    # Wizard pages for step-by-step workflow
│   ├── LoadDataPage          # GPS data import (NMEA files)
│   ├── FilterDataPage        # GPS point filtering (HDOP, RTK, Age)
│   ├── BoundaryPage          # Interactive boundary selection
│   ├── ProjectionPage        # Coordinate system setup
│   ├── DemGenerationPage     # DEM creation
│   ├── DemPreviewPage        # DEM visualization
│   └── ExportPage            # Export format selection and processing
├── Services/                 # Core processing services
│   ├── Boundary/             # Boundary filtering services
│   ├── Dem/                  # DEM generation services
│   ├── Export/               # Export format handlers
│   ├── Filter/               # GPS point filtering
│   ├── Projection/           # Coordinate system projection
│   └── Streaming/            # Large dataset processing
├── Models/                   # Data models and event arguments
└── Dialogs/                  # Custom dialog windows

Key Services

High-Performance Services

• HighPerformanceBoundaryFilter: Parallel boundary filtering with bounding box optimization
• HighPerformanceFilter: Multi-threaded GPS point filtering
• StreamingDemService: Memory-efficient DEM generation for massive datasets
• RgFdemExportService: Agricultural-optimized single-file export

Export Services

• RgFdemExportService: Creates .RgFdem files for ABLS integration
• GdalExportService: GeoTIFF export with GDAL integration
• StreamingExportService: Large dataset export handling

🔧 Technical Requirements

System Requirements

• OS: Windows 10/11 (x64)
• Framework: .NET 8.0
• RAM: 8GB minimum, 16GB+ recommended for large datasets
• Storage: SSD recommended for large GPS file processing

Dependencies

• .NET 8.0 Windows: Core framework
• WPF: User interface framework
• GMap.NET: Interactive mapping and satellite imagery
• GDAL: Geospatial data processing and GeoTIFF export
• Triangle.NET: Delaunay triangulation for DEM generation
• SQLite: Data storage and indexing
• Ookii.Dialogs: Enhanced file dialogs

📦 Installation

Prerequisites

1. Install .NET 8.0 Runtime
2. Install Visual Studio 2022 (for development)

Building from Source

git clone https://github.com/yourusername/DEMBuilder.git
cd DEMBuilder
dotnet restore
dotnet build --configuration Release

Running the Application

dotnet run
# OR
DEMBuilder.exe

🎯 Usage Guide

Step-by-Step Workflow

1. Load GPS Data

• Import NMEA files from GPS logging devices
• Supports multiple file selection
• Automatic parsing of GPS coordinates, HDOP, RTK status, and timestamps

2. Filter GPS Points

• HDOP Filter: Remove points with poor horizontal accuracy
• RTK Status Filter: Keep only RTK Fixed/Float points
• Age Filter: Remove points with old differential corrections
• Real-time progress tracking with parallel processing

3. Define Field Boundary

• Interactive satellite map view
• Draw boundary polygon by clicking points
• Visual feedback with GPS points overlay
• High-performance boundary filtering with progress tracking

4. Set Coordinate System

• Automatic reference point calculation
• AgOpenGPS-compatible local tangent plane projection
• Manual reference coordinate adjustment if needed

5. Generate DEM

• Delaunay triangulation of GPS points
• Configurable resolution (default: 0.25m/pixel)
• Memory-efficient processing for large datasets

6. Preview Results

• Visual DEM preview with elevation coloring
• Quality assessment before export

7. Export DEM

Choose from multiple export formats:

RgF DEM (.RgFdem) - Recommended

• Single-file agricultural package
• Optimized for ABLS tractor software
• Filename: Farm_Field_ddmmyy.RgFdem
• Contains: metadata, binary elevation data, coordinate system info

GeoTIFF (.tif)

• AgOpenGPS-compatible format
• Tiled output for large areas
• GDAL-based export with proper georeferencing

Text File (.txt/.asc)

• ASCII grid format
• Human-readable elevation data
• Compatible with GIS software

📁 File Formats

RgF DEM Format (.RgFdem)

The proprietary RgF DEM format is a ZIP-based container optimized for agricultural use:

Farm_Field_ddmmyy.RgFdem
├── metadata.json           # Complete DEM parameters and bounds
├── elevation.dem          # Binary elevation data (int32 header + float32 grid)
├── coordinate_system.txt  # AgOpenGPS coordinate system info
└── README.txt            # Human-readable documentation

Key Features:

• Single file for easy transfer
• Optimized for USB drives and wireless transfer
• AgOpenGPS-compatible coordinate system
• Complete metadata for ABLS integration

See RgF_DEM_File_Format_Specification.md for complete technical details.

⚡ Performance Optimizations

Large Dataset Handling

• Streaming Processing: Process datasets larger than available RAM
• Parallel Filtering: Multi-core CPU utilization for point filtering
• Bounding Box Optimization: 80-90% reduction in polygon tests
• Memory Management: Efficient memory usage for 600,000+ point datasets

UI Responsiveness

• Asynchronous Operations: Non-blocking UI during processing
• Progress Reporting: Real-time progress updates every 1000 points or 100ms
• Cancellation Support: User can cancel long-running operations
• Visual Feedback: Progress bars and status messages throughout

Export Optimization

• Chunked Processing: Process large DEMs in manageable chunks
• Compression: ZIP-based containers for smaller file sizes
• Binary Formats: Efficient storage of elevation data
• Parallel Export: Multi-threaded export processing

🔧 Configuration

Default Settings

• Resolution: 0.25 meters/pixel
• Tile Size: 50 meters (for GeoTIFF export)
• Batch Size: 10,000 points for parallel processing
• Progress Updates: Every 1,000 points or 100ms
• Coordinate System: Local tangent plane (AgOpenGPS compatible)

Customization

Settings can be adjusted in the UI:

• Export resolution and tile size
• Filter thresholds (HDOP, Age)
• Reference coordinates
• Farm and field names

🐛 Troubleshooting

Common Issues

GDAL Initialization Failed

• Ensure GDAL native libraries are properly installed
• Check GDAL_DATA environment variable
• Verify all GDAL DLLs are in the application directory

Out of Memory Errors

• Use streaming processing for datasets >500,000 points
• Increase system RAM or use smaller data chunks
• Close other applications to free memory

Slow Performance

• Ensure SSD storage for large GPS files
• Use parallel processing (enabled by default)
• Consider reducing dataset size or resolution

Export Failures

• Check available disk space
• Verify write permissions to output directory
• Ensure valid farm/field names (no special characters)

Debug Information

• Debug logs are written to debug.log in the application directory
• GDAL diagnostic information available in export dialogs
• Progress and performance metrics displayed during operations

🤝 Contributing

Development Setup

1. Clone the repository
2. Install Visual Studio 2022 with .NET 8.0 support
3. Restore NuGet packages: dotnet restore
4. Build solution: dotnet build

Code Structure

• Follow existing naming conventions
• Use async/await for long-running operations
• Implement progress reporting for user operations
• Add comprehensive error handling
• Include XML documentation for public APIs

Testing

• Test with large datasets (100,000+ points)
• Verify memory usage and performance
• Test all export formats
• Validate coordinate system accuracy

📄 License

This project is open source. See LICENSE file for details.

🏢 ABLS Integration

DEMBuilder is designed to integrate seamlessly with ABLS (Agricultural Baseline Location System) tractor software:

• RgF DEM Format: Optimized for ABLS consumption
• Coordinate System: AgOpenGPS-compatible local tangent plane
• File Transfer: Single files optimized for USB and wireless transfer
• Metadata: Complete technical specifications for integration

For ABLS developers, see RgF_DEM_File_Format_Specification.md for complete integration details.

📞 Support

For technical support or questions:

• Review troubleshooting section above
• Check debug logs for error details
• Ensure system meets minimum requirements
• Verify GPS data format compatibility (NMEA)

🔄 Version History

Latest Version

• ✅ RgF DEM export format with single-file packages
• ✅ High-performance parallel processing for large datasets
• ✅ Interactive boundary selection with progress tracking
• ✅ Multiple export formats (RgF DEM, GeoTIFF, Text)
• ✅ AgOpenGPS-compatible coordinate system
• ✅ Comprehensive error handling and user feedback
• ✅ Memory-efficient streaming processing
• ✅ Visual progress bars throughout application

Key Improvements

• Performance: 10x faster boundary filtering with parallel processing
• Memory: Streaming algorithms support unlimited dataset sizes
• UI/UX: Progress bars and responsive interface
• Export: Single-file RgF DEM format for agricultural use
• Compatibility: Full AgOpenGPS coordinate system support
• Reliability: Comprehensive error handling and recovery

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DEMBuilder - Precision agriculture starts with precise elevation data. 🚜📊