Spectral imaging is an imaging technique that introduces spectral filters in the imaging link to simultaneously obtain target spectral and spatial information. Among the spectral filters, liquid-crystal (LC) filters exhibit technical advantages of fast response speed, low power consumption, and large aperture. As a highly efficient electrically tunable microcavity interference filter structure, the miniaturized liquid-crystal Fabry-Pérot (LC-FP) is generally composed of a LC layer sandwiched by two highly reflective mirrors. By adjusting the applied voltage signals, the high spectral resolution spectrum selection and adjustment of transmitted beam is implemented. Generally, the birefringence difference of the LC material used determines the phase modulation capability, which in turn affects the device performance. In this paper, an electrically tunable LC-FP filter (ET LC-FP) with high-birefringence nematic LC mixture is proposed. The deviced ET LC-FP is constructed using a kind of high-birefringence nematic LC mixture (HB-45800) for achieving the typical electrically selecting and adjusting and jumping of spectral lightbeam outfrom the ET LC-FP filter. The electro-optical parameters of HB-45800 are: Δn = 0.385 at 589.3nm, the clear point is 95.1℃. The transmission spectral characteristics (1.5~15μm) of the ET LC-FP device were analyzed using a Fourier transform infrared spectrometer. Experiments demonstrate that an electrically tunable spectral resolution of better than 5nm is reached in the infrared domain of 1.5~3μm.
Silicon drift detector is widely used as X-ray spectrometer sensor. The advantage of this sensor is the ability to get the precise timing and high resolution spectrum. The dark current of the SDD was suppressed by the thermometric cooler, which cooling the detector to a nominal temperature of -52°C. The electronic circuits were made of two assemblies: the focal plane assembly and the Main Electronics Box. The outputs from the FPA were filtered by the fast and slow shaping amplifiers. Both shaping amplifiers were designed basing on a two stage Sallen-Key filters. The fast shaping amplifier, with 185 ns peaking time, was designed to get a better timing accuracy. The slow shaping amplifier, with 1.68 μs peaking timing, provided better energy resolution, along with the pile-up rejection circuits. A non-delay line constant fraction discriminator was adopted to acquire an accurate arrival time. The photon time-tag error mainly comes from two parts: time triggering and time stamping, which are 65.25 ns and 40 ns respectively. Thus the time jitter was 76.53 ns totally. The photon height was hold by the peak sample holder. The conversion relationship between the voltage and line energy was calibrated. The energy resolution was calculated from the Gaussian fitting. The fit to these values produced electronic noise of 11.38 electrons with 95% confidence level. The soft X-Ray spectrometer, as shown above, was capable of providing precise time resolution in conjunction with excellent energy resolution performance.
KEYWORDS: Infrared detectors, Signal detection, Reliability, Infrared sensors, Infrared radiation, Signal processing, Power supplies, Accelerated life testing, Control systems, Signal attenuation
In order to satisfy the reliability demand of the long-life satellite, and solve the weak link, we design an kind of the long service life integration CES (LFICES). In order to solve the problem from the late resistance increased product life, we perform the high torque motor technology research. Then we performed the accelerated life test of the rotating device. In the accelerated life test, we simulated operation of eight years, and the test results showed that the rotating device meet the design requirements of eight years. In this paper, we gives the design scheme of the LFICES. The telemetering data of the 26th remote sensing satellite in-orbit flight shows that the LFICES can stably work.
When the moon and the sun light enter into the field of view of the conical scanning earth sensor (CES), the real attitude of the spacecraft will be affected because of wrong CES measurements.To solve this problem, a new method based on the CES software can discriminate the interference effect.A series of ground are designed to verify this method effectiveness, and results indicate that this method can not only give a indication of the moon, but also can eliminate effect of the moon and the sun light on the CES’s measurements.Finally, the on-orbit flight data is presented to confirm this method validity.
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