Optical design of MWIR detection system for near-space infrared detecting

2015 ◽  
Author(s):  
Pei-pei Yan ◽  
Kai Liu ◽  
Gang Li ◽  
Qiusha Shan ◽  
Jing Duan ◽  
...  
Keyword(s):  
Detection System ◽  
Optical Design ◽  
Near Space

scholarly journals Infrared Optical Observability of an Earth Entry Orbital Test Vehicle Using Ground‐Based Remote Sensors

2019 ◽  
Vol 11 (20) ◽  
pp. 2404 ◽  
Author(s):  
Niu ◽  
Meng ◽  
He ◽  
Dong
Keyword(s):  
Detection System ◽  
Optical Design ◽  
Spectral Band ◽  
Radiative Properties ◽  
Design Parameters ◽  
Reacting Flow ◽  
Test Vehicle ◽  
Detection Range ◽  
Order Of Magnitude ◽  
The Difference

Optical design parameters for a ground-based infrared sensor rely strongly on the target’s optical radiation properties. Infrared (IR) optical observability and imaging simulations of an Earth entry vehicle were evaluated using a comprehensive numerical model. Based on a ground-based IR detection system, this model considered many physical mechanisms including thermochemical nonequilibrium reacting flow, radiative properties, optical propagation, detection range, atmospheric transmittance, and imaging processes. An orbital test vehicle (OTV) was selected as the research object for analysis of its observability using a ground-based infrared system. IR radiance contours, maximum detecting range (MDR), and thermal infrared (TIR) pixel arrangement were modeled. The results show that the distribution of IR radiance is strongly dependent on the angle of observation and the spectral band. Several special phenomena, including a strong receiving region (SRR), a characteristic attitude, a blind zone, and an equivalent zone, are all found in the varying altitude MDR distributions of mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) irradiances. In addition, the possible increase in detectivity can greatly improve the MDR at high altitudes, especially for the backward and forward views. The difference in the peak radiance of the LWIR images is within one order of magnitude, but the difference in that of the MWIR images varies greatly. Analyses and results indicate that this model can provide guidance in the design of remote ground-based detection systems.

Electron optical design of an EFTEM concerning optimum selection of imaging parameters for different sizes of detection systems

1995 ◽  
Vol 53 ◽  
pp. 308-309
Author(s):  
G. Benner ◽  
W. Probst ◽  
R. Rilk
Keyword(s):  
Detection System ◽  
Photographic Plate ◽  
Optical Design ◽  
Ccd Camera ◽  
Energy Window ◽  
Acceptance Angle ◽  
Detection Systems ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Specimen Area

The amount of information which can be gained about an object is considerably improved by the incorporation of an imaging energy filter in a TEM. Besides the conventional modes of operation elastic brightfield (EBF) and darkfield (EDF) imaging or diffraction are provided by an Energy Filtering Transmission Electron Microscope (EFTEM) as well as Electron Spectroscopic Imaging (ESI) or Electron Energy Loss Spectroscopy (EELS). Thus, the demands for carefully designed highly flexible electron optics are much more sophisticated as compared to a CTEM.One of the most important parameters for elastic imaging and ESI is the width of the energy window, which can be selected by a slit aperture of adjustable width according to the particular needs. This energy window defines the size of the transferable specimen area or diffraction pattern, respectively, as well as the acceptance angle of the spectrometer. In order to meet the optimum parameters concerning the energy window and the size of the detection system (e.g. photographic plate, image plate, Slow Scan CCD camera (SSCCD), TV camera, electron detector, etc.) the magnifications of the pre- and of the post-spectrometer projector lens systems has to be independently adjustable.

Detection Performance Analysis of Space-Based Radar to near Space Hypersonic Target

2014 ◽  
Vol 981 ◽  
pp. 730-734
Author(s):  
Song Xiao ◽  
Xian Si Tan ◽  
Hong Wang ◽  
Zhi Fang Zuo
Keyword(s):  
Performance Analysis ◽  
Detection System ◽  
Detection Performance ◽  
Flight Speed ◽  
Flight Distance ◽  
Range Searching ◽  
Detection Range ◽  
Near Space ◽  
Tracking Mode ◽  
Flight Height

Aimed at the problem that it is hard to detect near space hypersonic target for conventional radar because of its high flight speed, flight height, and flight distance and so on, the detection performance of space-based radar to near space hypersonic target was analyzed. The characteristics of near space hypersonic target and the advantages of space-based radar was introducted, and then, the detection performances of space-based radar to near space hypersonic target from detection range, searching and tracking mode were studied. It has certain guiding significance for space-based radar development and perfection of near space detection system.

scholarly journals Investigation of a metrological atomic force microscope system with a combined cantilever position, bending and torsion detection system

2021 ◽  
Vol 10 (2) ◽  
pp. 171-177
Author(s):  
Yiting Wu ◽  
Elisa Wirthmann ◽  
Ute Klöpzig ◽  
Tino Hausotte
Keyword(s):  
Atomic Force Microscope ◽  
Measurement System ◽  
Large Scale ◽  
Detection System ◽  
Optical Design ◽  
Signal Quality ◽  
Cantilever Deflection ◽  
Atomic Force ◽  
Areal Measurement

Abstract. This article presents a new metrological atomic force microscope (MAFM) head with a new beam alignment and a combined one-beam detection of the cantilever deflection. An interferometric measurement system is used for the determination of the position of the cantilever, while a quadrant photodiode measures the bending and torsion of the cantilever. To improve the signal quality and reduce disturbing interferences, the optical design was revised in comparison to the systems of others (Dorozhovets et al., 2006; Balzer et al., 2011; Hausotte et al., 2012). The integration of the MAFM head in a nanomeasuring machine (NMM-1) offers the possibility of large-scale measurements over a range of 25mm×25mm×5 mm with sub-nanometre resolution. A large number of measurements have been performed by this MAFM head in combination with the NMM-1. This paper presents examples of the measurements for the determination of step height and pitch and areal measurement.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

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