The power of the near-infrared channel in UltraCam sensors
6 February 2025
Vegetation monitoring and analysis have become increasingly important tools for understanding global climate change and addressing food insecurity. All UltraCam aerial sensors have the ability to capture near-infrared (NIR) data, which plays a crucial role in these applications. Let’s explore some key facts about the near-infrared channel and its benefits.
Vexcel’s UltraCam sensors capture near-infrared data in the range of approximately 680 to 1,000 nm—just beyond the visible spectrum. This capability enhances vegetation analysis and supports applications that require spectral data beyond standard RGB imagery.
All UltraCam sensors include a monochrome infrared channel. During Level 3 processing, a 3-band color infrared (CIR) image can be generated using the infrared, red, and green channels. CIR imagery is particularly useful for analyzing plant health and classifying land cover and land use.
Spectral sensitivity curve of an UltraCam Eagle 4.1
Light spectrum from ultraviolet to near-infrared
How near-infrared helps in vegetation analysis
Vegetation detection: The infrared channel plays a crucial role in identifying and analyzing vegetation.
Light reflection and plant health: Healthy plants reflect very little red and blue light, slightly more green light, and a significant amount of infrared light. The reflection of infrared light varies depending on the health and vigor of the vegetation. Stressed plants reflect more red and blue light but less infrared light.
Color infrared representation: These properties result in CIR images where healthy vegetation appears bright red, while stressed plants take on brownish tones, making it easier to assess plant health from aerial imagery.
Healthy vegetation reflects more infrared light. (Image courtesy of MidOpt, from the article Healthy Crop, with slight modifications.)
Expanding applications of near-infrared data
The near-infrared channel has been used in fields like forestry and agriculture, where it supports vegetation classification and the computation of vegetation indices. One of the most widely used indices is the Normalized Difference Vegetation Index (NDVI), which provides valuable insights into plant health and biomass estimation.
Beyond traditional vegetation analysis, the near-infrared channel has found new applications in recent years:
- Machine learning & AI: The inclusion of infrared data improves machine-learning algorithms, leading to more accurate food supply predictions and environmental assessments.
- Disaster mapping: Infrared imagery plays a crucial role in wildfire monitoring. Unlike standard RGB imagery, the infrared channel can "see" through smoke, providing a clearer view of fire-affected areas and damage extent.
- Insurance & risk analysis: Insurance companies use CIR images to assess fire risks. Dead trees and dry vegetation, which pose a higher fire risk, can be easily identified in infrared imagery.
- Automated object detection: Infrared images help municipalities detect features such as swimming pools in urban areas, as water appears nearly black (low reflectance) in infrared imagery.
- Water masking for land use classification: The unique spectral properties of water make it easy to identify and separate from land, aiding in land use and land cover classification.
RGB image of a wildfire with limited visibility: smoke obscures the view
CIR image for disaster mapping: revealing details through smoke
This CIR image (captured with an UltraCam Eagle 4.1) illustrates varying vegetation conditions. Stressed vegetation reflects less infrared light while reflecting more red, blue, and green light.
The future of near-infrared in aerial surveying
Aerial surveying is all about collecting actionable information. With the continuous advancement of remote sensing technologies, the near-infrared channel is set to become an even more valuable analytical tool. From precision agriculture and environmental monitoring to disaster response and urban planning, the applications of near-infrared imaging are expanding rapidly. That’s why every UltraCam sensor includes a near-infrared channel, ensuring that our users have access to the best possible data for their analysis needs.
Discover the power of near-infrared imaging with UltraCam sensors. Explore our solutions!
UltraCam portfolio
