87 lines
2.6 KiB
Markdown
87 lines
2.6 KiB
Markdown
# Sentinel-1 SAR Download for Aura Fields
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This folder contains scripts to download and preprocess Sentinel-1 SAR data for crop monitoring.
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## Quick Start
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### 1. Setup Environment
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```powershell
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# Navigate to the python_scripts directory
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cd "c:\Users\timon\Resilience BV\4020 SCane ESA DEMO - Documenten\General\4020 SCDEMO Team\4020 TechnicalData\WP3\smartcane\python_scripts"
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# Run setup script
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python setup_sar_environment.py
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```
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### 2. Get SentinelHub Credentials
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- Go to https://apps.sentinel-hub.com/
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- Create account (free tier available)
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- Get your Client ID and Client Secret
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- The script will prompt for these when you first run it
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### 3. Prepare Field Boundaries
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- Make sure you have your field boundaries in GeoJSON format
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- The script will look for files like:
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- `pivot.geojson` (current directory)
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- `pivot_20210625.geojson` (current directory)
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- `data/aura/field_boundaries/aura_fields.geojson`
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### 4. Download SAR Data
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```powershell
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python download_s1_aura.py
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```
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## What the Script Does
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1. **Downloads last 8 weeks** of Sentinel-1 data
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2. **Downloads both VV and VH polarizations**
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3. **Provides both linear and dB scales** for analysis
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4. **Applies basic speckle filtering**
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5. **Organizes by week** (week_XX_YYYY_BAND.tif format)
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## Output Structure
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```
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data/aura/weekly_SAR_mosaic/
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├── week_24_2025_VV.tif
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├── week_24_2025_VH.tif
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├── week_24_2025_VV_dB.tif
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├── week_24_2025_VH_dB.tif
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├── week_24_2025_VV_dB_filtered.tif
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├── week_24_2025_VH_dB_filtered.tif
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└── ... (for each week)
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```
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## Files Created
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- **`download_s1_aura.py`** - Main download script
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- **`requirements_sar.txt`** - Python dependencies
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- **`setup_sar_environment.py`** - Environment setup helper
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- **`sar_download.log`** - Download log file
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## Troubleshooting
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### Common Issues:
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1. **Import errors**: Run `python setup_sar_environment.py` first
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2. **Credential errors**: Make sure SentinelHub credentials are correct
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3. **No data found**: Check if field boundaries are loaded correctly
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4. **Large downloads**: SAR data can be large, ensure good internet connection
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### Check Log File:
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```powershell
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Get-Content sar_download.log -Tail 20
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```
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## Next Steps
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After successful download:
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1. Check the output files in `data/aura/weekly_SAR_mosaic/`
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2. Move to R for analysis and visualization
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3. Create SAR analysis scripts in R
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## Notes
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- **Free Tier Limits**: SentinelHub free tier has processing unit limits
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- **Data Size**: Each weekly mosaic can be 50-200MB depending on area
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- **Processing Time**: Downloads can take 5-15 minutes per week
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- **Format**: All outputs are GeoTIFF with proper CRS information
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