Vogelmann Red Edge Index 2
A vegetation index that uses specific red edge wavelengths to assess vegetation health and chlorophyll content. It is sensitive to changes in leaf internal structure and chlorophyll concentration.
Used in crop monitoring, forest monitoring, and mineral exploration.
When to use
- Time-series monitoring of crop health, growth stages, and stress detection
- Land cover classification and vegetation type discrimination
- Biomass estimation and net primary productivity studies
- Drought impact assessment over agricultural and forest areas
- Phenology tracking — green-up, peak season, and senescence
- Vegetation stress detection
- Chlorophyll content assessment
Limitations
- Saturates in dense canopies (LAI > 3) — values plateau and lose discrimination ability
- Sensitive to atmospheric scattering, especially blue-band haze
- Soil background contaminates measurements in sparsely vegetated areas
- Sun-sensor geometry (BRDF effects) introduces variability across acquisitions
- Cloud cover and shadows produce invalid pixels that need masking
- Requires four or more bands — limits portability across simpler sensors
What the values mean
| Surface type | Typical VOG2 |
|---|---|
| Open water, snow | -0.3 to -0.1 |
| Bare soil, urban | -0.1 to 0.2 |
| Sparse or stressed crops | 0.2 to 0.4 |
| Healthy crops, grassland | 0.4 to 0.7 |
| Dense forest, peak season | 0.7 to 0.9 |
General Formula
Sensor-Specific Formulas
Most-used sensors — click to show code below
| Sensor | Provider | Formula | Band Mapping |
|---|---|---|---|
| Wyvern | (Band 19 - Band 20) / (Band 17 + Band 18) | re1_715→Band 17, re1_726→Band 18, re2_734→Band 19, re2_747→Band 20 |
Spectral Band Visualization — Dragonette-1
Code Examples
Adapted for Dragonette-1 bands —
Frequently Asked Questions
What is the VOG2 (Vogelmann Red Edge Index 2) and when should I use it?
A vegetation index that uses specific red edge wavelengths to assess vegetation health and chlorophyll content. It is sensitive to changes in leaf internal structure and chlorophyll concentration. Vegetation indices quantify plant health, biomass, and photosynthetic activity by exploiting the contrast between how plants absorb visible light for photosynthesis and reflect near-infrared radiation from their cellular structure. VOG2 is particularly suited for vegetation stress detection, chlorophyll content assessment, forest health monitoring. The general formula is (re2_734 - re2_747) / (re1_715 + re1_726), which requires re1_715 and re1_726 and re2_734 and re2_747 spectral bands.
Which satellite sensors can I use to calculate VOG2?
VOG2 is supported by 2 satellite sensors in our database, including Dragonette-1, Dragonette-2/3. Each sensor uses different band designations — for example, Dragonette-1 uses the formula (Band 19 - Band 20) / (Band 17 + Band 18), while Dragonette-2/3 uses (Band23 - Band24) / (Band21 + Band22). Select a sensor above to see its specific band mapping.
What spectral bands does VOG2 require and why?
VOG2 requires re1_715 (715), re1_726 (726), re2_734 (734), re2_747 (747). Vegetation strongly absorbs red light for photosynthesis while reflecting near-infrared light from its mesophyll cell structure, making this contrast a reliable indicator of plant vigour.
How do I calculate VOG2 in Python or R?
Both Python and R code samples are provided above. In Python, use rasterio to load individual band GeoTIFF files and numpy for the arithmetic. In R, the terra package handles raster operations efficiently. The key is to load bands as floating-point arrays to avoid integer division, and to handle division-by-zero cases where the denominator equals zero. For production use, consider applying a valid data mask to exclude no-data pixels before calculation.
How does VOG2 compare to NDVI and other vegetation indices?
While NDVI is the most common vegetation index, VOG2 provides complementary information that NDVI cannot capture on its own. The choice of index depends on your application, sensor availability, and atmospheric conditions.
VOG2 vs other vegetation indices
| Index | Name | How it differs |
|---|---|---|
| ARI | Anthocyanin Reflectance Index | Alternative vegetation index — different band combination |
| mARI | Modified Anthocyanin Reflectance Index | Refined formulation for specific conditions |
| ARVI | Atmospherically Resistant Vegetation Index | Atmospherically corrected version |
| ARVI2 | Atmospherically Resistant Vegetation Index 2 | Atmospherically corrected version |
Related Vegetation Indices
References
Need help choosing?
Ask our AI assistant for sensor recommendations, code examples, or how VOG2 compares to other indices for your specific use case.