KEYWORDS: Temperature metrology, Data modeling, Signal to noise ratio, Black bodies, Spectroscopy, Spectral resolution, Statistical modeling, Mathematical modeling
Accurate measurement of the emissivity, temperature of distant targets has important applications in the field of infrared remote sensing, aerospace heat-resistant material development, military industry and many other fields.Based on Planck's law, the essence of multispectral radiation thermometry(MRT) is to solve nonlinear equations with more unknowns than equations.In order to solve this problem, a new calculation method based on the slow variation characteristic of emissivity is proposed in this paper to reduce the number of unknowns and simplify the calculation. Based on the theoretical radiation spectrum, this method can be used to calculate the spectral emissivity, temperature and distance under some specific emissivity models.The more steady the variation of spectral emissivity is, the smaller the spectral resolution is, the more accurate this method will be.With the development and improvement of resolution and signal-to-noise ratio of spectrographs, this method will have a broad application prospect.
Field of view is a principle parameter of the push-broom imaging spectrometer which mainly affects its working efficiency. Integration of multiple sub-modules with smaller field of view is an optional solution to gain wider field of view. An approach for field registration and test for multi-module imaging spectrometer is presented. A single beam is reflected by multiple angle-tunable mirrors into multiple beams with different directions, which then enter the multimodule imaging spectrometer. Thus, one sub-module responses to lights with multiple incident angles simultaneously. A field registration platform is designed, which includes a collimating beam simulator, a multi-field beam generator, and an instrument support frame. The collimating beam simulator is composed of a collimator, an illuminant source, and a twodimensional shift pinhole target placed in the collimator focal plane. The multi-field beam generator is composed of a rotary table and multiple angle-tunable mirrors. The postures and the numbers of the mirrors are determined by the field registration requirement of the multi-module imaging spectrometer. Field registration is operated by monitoring the pixel response of the sub-module detector, and is tested by the two-dimensional shift of the pinhole target. Field registration was implemented on the platform for an airborne multi-module imaging spectrometer. Test result showed that the field registration is less than 0.2 pixels. Flight data of the imaging spectrometer demonstrated its good field registration alignment, which verified the engineering feasibility and value of the field registration approach.
We launched into a development of a new stand-off sensing system that can detect atmospheric and hazardous gases in real atmosphere utilizing THz technology. Narrow line width, <0.1 cm-1, long-wave (mid-IR and THz) source based on difference frequency generation (DFG) in collinear configuration in GaSe0.91S0.09:Al(0.03 at. %) using seeded YAG laser and KTP OPO as pump sources was designed. The low optical loss coefficient and large hardness, together with the simplicity of the processing, make GaSe0.91S0.09:Al(0.03 at. %) as a high-reliable and effective THz-wave generator suitable for out-of-door application. We demonstrate incoherent terahertz wave detection by stand-off room temperature Schottky diodes located at over 110 m using open waveguide formed by multitude HPE lenses, mirrors and/or unpolished reflectors.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.