جستجوی مقالات مرتبط با کلیدواژه « shortwave infrared » در نشریات گروه « فنی و مهندسی »

Star based navigation could be a good alternative for GPS. However there are some limitations. The most important problem is stars detection in daytime. In the near infrared region, reduction of solar radiation is noticeable, hence, radiance of sky (which is sunlight scattering in the sky) noticeably decreases in this spectral window. This region was covered by visible CCD so feasibility study of stars detection in daytime in near infrared can significantly reduce costs in comparison common shortwave infrared systems. . In this paper, sky transmittance is calculated for different wavelengths and sun zenith angles. According to a given model, the intensity of stars light is simulated in near-infrared and evaluated the components of the optical system until a model is presented about stars detection in daytime for the first time. Magnitude of some stars such as Betelgeuse, Vega and Mirach are simulated by the presented model. Also observed magnitude through three optical systems simulated and Ability to detect of the mentioned stars are confirmed. Finally, experimental data are measured by using appropriate optical equipment and servo motor (for star tracking in sky) that these data confirm result of presented model.