NDVI Surveys
Traditionally, true aerial NDVI was used to survey and evaluate crop or forest health, incorporating cameras with at least a red and near-infrared (NIR) filter to collect aerial imagery that would then be processed using the equation NDVI = (NIR – Red) / (NIR + Red).
AGRICULTURAL SURVEILLANCE USING OPTICAL FILTERS
Scientific advances have found that modifying traditional NDVI calculations (above) can provide even more detail about plant health. In addition to reflecting NIR light, healthy plants will also reflect some green light. Thus multispectral imagery can sometimes be used to make more precise, better informed decisions regarding water, fertilizer or pesticide applications.
SINGLE AND MULTI-BANDPASS FILTERS
MidOpt has designed innovative Single Band, Dual band and Triple band filters, which allow one camera to gather data results at multiple wavelengths, making them an affordable, lightweight alternative to aerial surveillance applications that otherwise might require three or more cameras or sensors.
PROTECTIVE WINDOWS
These Protective Windows are ideal for use in Aerial plant surveillance. They can be combined with a Bandpass filters to help protect the lens. Protective Windows are available in various substrates such as industrial glass, acrylic and sapphire, and are also available with A/R (anti-reflection) Oleophobic (anti-oil, water and smudge) coatings.
MIDOPT FILTERS FOR NDVI
Single Bandpass Filters
| Description: | Useful Range: | StablEDGE® | |
 | Bi650 Red Interference Bandpass Filter | 643-665nm | |
 | Bi725 Red Edge Bandpass Filter | 717-732nm | |
| Bi850 Near-IR Interference Bandpass Filter | 845-860nm |
Multi Bandpass Filters
| Description: | Useful Range: | StablEDGE®: | |
 | DB550/850 Dual Bandpass Green + 850nm NIR | 535-565nm, 830-870nm | |
 | TB475/550/850 Triple Bandpass Blue+Green+850nm NIR | 468-483nm, 543-558nm, 835-865nm | |
 | TB550/660/850 Triple Bandpass Green+Red+850nm NIR | 543-558nm, 653-668nm, 835-865nm |
Protective Windows
| Description: | Useful Range: | StablEDGE: | |
 | AC370 Acrylic Oleophobic A/R Protective Window | 380-850nm | √ |
| AC400 Acrylic Oleophobic-Coated UV-Block Protective Window | 415-1100nm | √ |
| LP286 Borofloat® Oleophobic A/R Coated Protective Window | 350-1100nm | √ |
| LP190 Sapphire Protective Window | 250-2300nm |
Neutral Density
| Description: | Useful Range: | Optical Density: | |
 | ND030 Neutral Density Filter - Absorptive 50% Transmission | 425-675nm | 0.3 |
 | ND060 Neutral Density Filter - Absorptive 25% Transmission | 425-675nm | 0.6 |
 | ND090 Neutral Density Filter - Absorptive 12.5% Transmission | 425-675nm | 0.9 |
 | ND120 Neutral Density Filter - Absorptive 6.25% Transmission | 425-675nm | 1.2 |
 | ND200 Neutral Density Filter - Absorptive 1.0% Transmission | 425-675nm | 2.0 |
 | ND300 Neutral Density Filter - Absorptive 0.1% Transmission | 425-675nm | 3.0 |
 | ND400 Neutral Density Filter - Absorptive 0.01% Transmission | 425-675nm | 4.0 |