Intercepting an intercontinental ballistic missile (ICBM) in its boost phase requires imaging of the hard body as well as the rocket plumes. The scientists reported that fusing these two images increased detection capabilities. If the intensity of the blue image changes when scanning, that region is likely disturbed. The blue detector is sensitive to wavelengths of 9.3 micrometers. The red detector acts as a backdrop, verifying realms of undisturbed soil areas, as it is sensitive to the 10.4 micrometer wavelength. The US Army Research Laboratory's dual MWIR/LWIR FPA used 'red' and 'blue' detectors to search for areas with enhanced emissivity. Disturbed soil has increased emissivity in the wavelength range of 8.5 to 9.5 micrometers while demonstrating no change in wavelengths greater than 10 micrometers. Surface and sub-surface soil possess different physical and chemical properties that appear in spectral analysis. Land mine detection īy analyzing the emissivity of ground surfaces, multispectral imaging can detect the presence of underground missiles. The US Army reports that its dual band LWIR/MWIR FPA demonstrated better visualizing of tactical vehicles than MWIR alone after tracking them through both day and night. Dual band MWIR and LWIR technology resulted in better visualization during the nighttime than MWIR alone. įor nighttime target detection, thermal imaging outperformed single-band multispectral imaging. Researchers claim that dual-band technologies combine these advantages to provide more information from an image, particularly in the realm of target tracking. However, LWIR operates better in hazy environments like smoke or fog because less scattering occurs in the longer wavelengths. Imaging systems that use MWIR technology function better with solar reflections on the target's surface and produce more definitive images of hot objects, such as engines, compared to LWIR technology. This reflection may misconstrue the true reading of the objects’ inherent radiation. Sometimes the surface of the target may reflect infrared energy. These signatures are less pronounced in hyperspectral systems (which image in many more bands than multispectral systems) and when exposed to wind and, more dramatically, to rain. Every material has an infrared signature that aids in the identification of the object. The brightness of the image produced by a thermal imager depends on the objects emissivity and temperature. Because mid-wave infrared (MWIR) and long wave infrared (LWIR) technologies measure radiation inherent to the object and require no external light source, they also are referred to as thermal imaging methods.

This FPA allowed researchers to look at two infrared (IR) planes at the same time. In 2003, researchers at the United States Army Research Laboratory and the Federal Laboratory Collaborative Technology Alliance reported a dual band multispectral imaging focal plane array (FPA). Multispectral imaging measures light emission and is often used in detecting or tracking military targets. Hyperspectral imaging is a special case of spectral imaging where often hundreds of contiguous spectral bands are available. Multispectral imaging measures light in a small number (typically 3 to 15) of spectral bands. Multispectral imaging has also found use in document and painting analysis. Early space-based imaging platforms incorporated multispectral imaging technology to map details of the Earth related to coastal boundaries, vegetation, and landforms. It was originally developed for military target identification and reconnaissance. It can allow extraction of additional information the human eye fails to capture with its visible receptors for red, green and blue. The wavelengths may be separated by filters or detected with the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, i.e. Multispectral imaging captures image data within specific wavelength ranges across the electromagnetic spectrum. The bright yellow patches in other parts of the image are hollows. Video by SDO simultaneously showing sections of the Sun at various wavelengths Multispectral image of part of the Mississippi River obtained by combining three images acquired at different nominal wavelengths (800nm/infrared, 645nm/red, and 525nm/green) by Apollo 9 in 1969 Multispectral image of Bek crater and its ray system on the surface of Mercury, acquired by MESSENGER, combining images at wavelengths of 996, 748, 433 nm.

Not to be confused with spectral analysis.

Multispec color samples