A number of studies suggest that the Short Wave InfraRed (SWIR) band (0.9-1.7μm), offers a significant advantage over the visible for long-range daytime scenarios. This advantage of SWIR is due in particular to its excellent optical penetration in the presence of aerosols thanks to reduced light-scattering effects, allowing good scene contrast to be maintained over very long distances. This study reports the results of a field evaluation campaign, involving Lynred’s SNAKE TECLESS (TL) sensor (640x512@15μm, InGaAs) along size narrow field optics. This year-long campaign features a variety of atmospheric conditions, weathers and aerosol types. Those targets are at distances ranging between 10km and 84km. Finally, we compare the image obtained with SWIR sensors having a pixel pitch of 15μm and 10μm, with the same objective lenses, in order to conclude on the interest of reducing the pixel pitch for a gain in range.
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