Calculation Panel
Select an index and input reflectance values (0.0 to 1.0) or DNs.
Result
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Spectral Index Library
Browse available remote sensing indices. Click 'Use' to load them into the calculator.
Spectral Band Guide
General overview of typical multispectral bands used in calculations.
Note: Wavelength ranges and band numbers vary significantly between sensors (Landsat, Sentinel-2, MODIS). Always check sensor-specific metadata.
| Band Name | Typical Wavelength (nm) | Primary Remote Sensing Applications |
|---|---|---|
| Blue | 450 - 510 | Coastal mapping, soil/vegetation differentiation, atmospheric correction. |
| Green | 530 - 590 | Assessing plant vigor, mapping healthy vegetation, water body penetration. |
| Red | 630 - 690 | Vegetation discrimination (chlorophyll absorption), soil boundary mapping. |
| Red Edge | 700 - 740 | Plant stress, chlorophyll content estimation (often found on Sentinel-2). |
| NIR (Near Infrared) | 770 - 895 | Biomass content, coastline mapping, water body delineation, plant health. |
| SWIR 1 (Shortwave IR) | 1550 - 1750 | Moisture content in soil and vegetation, snow/cloud differentiation. |
| SWIR 2 (Shortwave IR) | 2080 - 2350 | Mineral mapping, burn severity mapping, geology. |
| Thermal | 10400 - 12500 | Land surface temperature, soil moisture estimation. |
How It Works
- Select an Index: Choose from the library based on your analysis goal (e.g., vegetation, water).
- Enter Band Values: Input reflectance values (usually 0.0 to 1.0) derived from atmospherically corrected satellite imagery (Surface Reflectance).
- Calculate: The tool computes the mathematical formula instantly.
- Interpret: Use the indicative ranges to understand the pixel's physical properties.
Scientific Note
Spectral indices are indicators, not absolute measurements. Interpretation thresholds vary by sensor, atmospheric conditions, land cover type, and season. Data preprocessing (e.g., Top-of-Atmosphere to Surface Reflectance correction) is highly recommended for accurate multitemporal analysis.
Example Calculation: NDVI
Scenario: Healthy Vegetation
Values: Red = 0.08, NIR = 0.72
Formula: (NIR - Red) / (NIR + Red)
Step 1: (0.72 - 0.08) = 0.64
Step 2: (0.72 + 0.08) = 0.80
Step 3: 0.64 / 0.80 = 0.8000
Result: High value indicates dense, healthy vegetation.
Frequently Asked Questions
A spectral index is a mathematical equation applied to different spectral bands of a satellite image. It highlights specific features like vegetation health, water bodies, or burn scars by exploiting the unique reflectance signatures of these materials across different wavelengths of light.
NDVI (Normalized Difference Vegetation Index) requires the Red band (visible light absorbed by chlorophyll) and the Near-Infrared (NIR) band (strongly reflected by leaf cell structure).
Yes, this calculator works with values from any multispectral sensor (Sentinel-2, Landsat 8/9, MODIS, PlanetScope) as long as you input the correct reflectance values corresponding to the required physical band (e.g., put Sentinel-2 Band 8 or Landsat 8 Band 5 into the "NIR" input field).
Absolutely. For accurate and comparable results, especially over time (time-series analysis), you should use Surface Reflectance (SR) data (atmospherically corrected) rather than Digital Numbers (DN) or Top-Of-Atmosphere (TOA) reflectance.
Yes, it is 100% free. All calculations are performed directly in your web browser (client-side). No data is uploaded to any server. Your calculation history is saved only in your browser's local storage.