Hyperspectral imaging is the process of photographically acquiring data from across the electromagnetic spectrum, with the aim of obtaining spectral information in each pixel of a captured image. This detailed technique uses multiple imaging methodologies to photograph a scene across the spectral range in many contiguous spectral bands.
Hyperspectral imaging spectrometers cover wavelengths beyond the visible spectrum, with a broad spectral range between 0.2 μm and up to 2.5 μm, with an outstanding spectral resolution. This allows hyperspectral instruments to capture multi-dimensional imagery to finely-tunable degrees, from an astronomical scale to microscopic one.
Delta Optical Thin Film previously explored the process of hyperspectral imaging and using continuously variable bandpass filters to optimize data acquisition, but this article will focus on the applications of hyperspectral imaging in more detail:
Hyperspectral imaging is used in astronomy to attain spatially resolved spectra relating to objects or clusters at great distances from the earth. It has enabled astronomers to map the astronomical distributions of far-off galaxies, and to remotely analyze a planet’s surface or atmospheric composition by providing spectrum data per-pixel with numerous adjacent wavelength bands.
Improved optical filters have enabled cheaper and more efficient hyperspectral imaging techniques for astronomy applications, improving telescopic equipment and informing observations and conclusions about structures within and beyond our galaxy.
Food & Drink
With extremely narrow adjacent spectral bands, hyperspectral imaging equipment can accurately detect the presence of chemicals or foreign material in products that are meant for human consumption. This process can be integrated with mechanical hardware to distinguish contaminated goods and remove them from the production line, improving inspection procedures in food and drink factory environments.
Hyperspectral sorting devices require ultra-precise instrumentation capable of determining trace materials with high degrees of accuracy, necessitating accurate optical filters to block or omit unnecessary wavelengths.
While hyperspectral imaging spectrometers for astronomy require expensive and robust telescopic equipment, the applicable instrumentation is more versatile when hyperspectral imaging is applied to our own planet. New imaging equipment is being used for crop monitoring by analyzing the light reflected from crops at various stages of growth. Researchers use satellite imagery or drones equipped with hyperspectral cameras to assess a crops’ physiological condition and react to perceived nutritional changes or diseases.
This process is known as precision agriculture. It is designed to optimize the agronomic industry with minimal invasiveness to ensure a consistent and organic food supply, and to acquire data capable of informing future agricultural best practices.
Military advancements are characterized by measures and countermeasures – for example, military personnel have learned to obscure their heat signatures from sophisticated infrared imaging systems. However, hyperspectral imaging provides such a broad range of spectra that it is difficult to counteract by conventional camouflaging methods. This improves the accuracy of target acquisition, with potential uses in determining an individual’s emotional or physiological state by analyzing their unique signatures.
Hyperspectral Imaging from Delta Optical Thin Film
Delta Optical Thin Film provide a range of products suited to established and emerging hyperspectral imaging techniques, including custom continuously variable bandpass filters to suit unique disciplines. Our standardized Bifrost filters are available with central wavelength ranges of 450 nm – 880 nm, or 796 nm – 1084 nm.