Abstract

A terahertz graphene Josephson junction detection system based on readout of a microwave resonant circuit includes a graphene Josephson junction detector, a microwave resonant readout circuit, and a microwave network analyzer. The graphene Josephson junction detector and the microwave resonant readout circuit form a microwave resonant circuit. A terahertz signal causes a change of an equivalent microwave inductance of the graphene Josephson junction detector, such that a resonant frequency and a quality factor of the microwave resonant circuit are changed. The present disclosure monitors the resonant frequency and the quality factor of the microwave resonant circuit with the microwave network analyzer, thereby realizing high-sensitivity detection on the terahertz signal. Compared with conventional direct-current (DC)-biased readout, readout of the microwave resonant circuit is not interfered by an external magnetic field, and has a strong interference resistance.

IPC Classes  ?

• G01R 33/32 - Excitation or detection systems, e.g. using radiofrequency signals
• G01R 33/035 - Measuring direction or magnitude of magnetic fields or magnetic flux using superconductive devices
• H10N 60/12 - Josephson-effect devices
• H10N 60/80 - Constructional details

Abstract

In a search and tracking method for full time-domain laser detection of space debris, a set of latest precision orbital parameters of a debris object and start and end moments of a current transit of the object are first obtained. Search-specific guidance data is generated based on the above information and in combination with estimation of a maximum along-track error of the orbital parameters of the object during the current transit. A DLR system performs multi-elevation search on the object based on the search-specific guidance data, obtains a plurality of pieces of detection data of the object after detecting the object during the search, determines an along-track error of the orbital parameters of the object based on the detection data, and corrects the orbital parameters of the object in real time based on the along-track error, so as to guide the DLR system to subsequently track and detect the object.

IPC Classes  ?

• B64G 3/00 - Observing or tracking cosmonautic vehicles
• B64G 1/24 - Guiding or controlling apparatus, e.g. for attitude control
• B64G 1/68 - Arrangements or adaptations of apparatus or instruments, not otherwise provided for of meteoroid or space debris detectors
• G01S 13/86 - Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• G01S 13/933 - Radar or analogous systems, specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft
• G01S 17/66 - Tracking systems using electromagnetic waves other than radio waves
• G01S 17/87 - Combinations of systems using electromagnetic waves other than radio waves
• G01S 17/933 - Lidar systems, specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft

Abstract

A target capturing and tracking method for full-time-domain laser detection of space debris, a storage medium, and an electronic device. In the method, firstly, a group of latest precise orbit parameters of a debris target and a starting moment and an ending moment of the target transiting this time are acquired, and the information and the estimation of the maximum along-track error of a target orbit parameter are used to generate search guide data; a DLR system performs multi-elevation search on the target on the basis of the search guide data, acquires a plurality of pieces of detection data of the target after capturing and discovering the target in the search process, determines the along-track error of the target orbit parameter by using the detection data, and corrects the target orbit parameter in real time on the basis of the along-track error; the corrected orbit parameter is used for generating a precise point forecast of the target, and the DLR system is guided to perform subsequent tracking and detection on the target. The present invention expands efficient detection resources of a DLR system, optimizes the phase distribution structure of DLR data, and greatly improves the orbit determination and forecast precision of space debris.

IPC Classes  ?

• G01S 17/50 - Systems of measurement based on relative movement of target

Abstract

An omnidirectional measurement system for a time-varying characteristic of atmospheric vapor radiation includes an antenna and calibrator assembly, a receiver assembly, a room temperature IF assembly, and a data acquisition and system control assembly. Atmospheric vapor features a wide profile and strong radiation in a frequency band of 183 GHz, and is often seen in the characteristic measurement of atmospheric vapor in high-altitude areas. The omnidirectional measurement system combines a superconductor-insulator-superconductor (SIS) mixer with high detection sensitivity in the frequency band of 183 GHz with a structure that integrates pitch scanning, omnidirectional scanning, and automatic calibration to achieve fast and high-precision omnidirectional scanning measurement of the time-varying characteristic of atmospheric vapor radiation. The omnidirectional measurement system has a pitch adjustment-based fast omnidirectional scanning function, and can measure the time-varying characteristic of atmospheric vapor radiation with higher precision and higher temporal resolution through the SIS mixer with higher sensitivity.

IPC Classes  ?

• G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
• G01J 5/00 - Radiation pyrometry, e.g. infrared or optical thermometry
• G01J 5/53 - Reference sources, e.g. standard lampsBlack bodies
• G01J 5/54 - Optical arrangements
• G01J 5/80 - Calibration
• G01J 5/20 - Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• G01N 21/3586 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared lightInvestigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using Terahertz radiation by Terahertz time domain spectroscopy [THz-TDS]
• G01W 1/06 - Instruments for indicating weather conditions by measuring two or more variables, e.g. humidity, pressure, temperature, cloud cover or wind speed giving a combined indication of weather conditions

Abstract

An omnidirectional measurement system for radiation and time-varying characteristics of atmospheric water vapor, comprising an antenna scanning and calibrating assembly, a receiver assembly, a normal-temperature intermediate-frequency assembly, and a data collection and system control assembly. Atmospheric water vapor has a wide profile and a strong radiation characteristic in the 183 GHz frequency band, which is commonly used for atmospheric water vapor characteristic measurement in high altitude areas. By using a superconducting SIS mixer having high detection sensitivity in the 183 GHz frequency band and in combination with an integrated structure of pitch scanning, omnidirectional scanning and automatic calibration, the omnidirectional measurement system for radiation and time-varying characteristics of atmospheric water vapor achieves rapid omnidirectional scanning and high-precision measurement of radiation and time-varying characteristics of atmospheric water vapor. Compared with a conventional radiometer or Fourier-transform spectrometer, the omnidirectional measurement system for radiation and time-varying characteristics of atmospheric water vapor has quick pitch adjustment and omnidirectional scanning functions, and uses a superconducting SIS detector having high sensitivity, thereby implementing high-precision and high time-resolved measurement of radiation and time-varying characteristics of atmospheric water vapor.

IPC Classes  ?

• G01N 21/3581 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared lightInvestigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using Terahertz radiation

Abstract

Provided in the present invention is a terahertz graphene Josephson junction detection system based on a microwave resonant circuit readout, which system comprises a graphene Josephson junction detector, a microwave resonant readout circuit, a microwave network analyzer, etc., wherein the graphene Josephson junction detector and the microwave resonant readout circuit jointly constitute a microwave resonant circuit. A terahertz signal results in a change in the equivalent microwave inductance of the graphene Josephson junction detector, and further results in changes in the resonant frequency and a quality factor of the microwave resonant circuit. In the present invention, the changes in the resonant frequency and the quality factor of the microwave resonant circuit are monitored by using the microwave network analyzer, such that high-sensitivity detection of the terahertz signal is realized. In comparison with a conventional direct-current bias readout, a microwave resonant circuit readout is not affected by an external magnetic field, and has a strong anti-interference capability. In addition, the graphene Josephson junction detector and the microwave resonant readout circuit can be monolithically integrated, such that the implementation of a large-scale terahertz graphene Josephson junction array detector is easier.

IPC Classes  ?

• G01J 1/42 - Photometry, e.g. photographic exposure meter using electric radiation detectors

Abstract

A space debris observation method based on alternating exposure times of a charge coupled device (CCD) camera is provided. The present disclosure controls the CCD camera to acquire consecutively and alternately short-exposure and long-exposure images based on preset exposure times. The present disclosure realizes detection and astronomical positioning of low-orbit, medium-orbit and high-orbit space debris by processing short-exposure images of odd-numbered frames. The present disclosure realizes detection of medium-orbit and high-orbit space debris by processing long-exposure images of even-numbered frames, and realizes astronomical positioning of the medium-orbit and high-orbit space debris detected in a current frame through plate constant model coefficients of adjacent odd-numbered frames. In addition, in a search mode, the present disclosure realizes precise astronomical positioning of low-orbit, medium-orbit and high-orbit space debris through a multi-point adjustment method and the plate constant model coefficients of adjacent odd-numbered frames.

IPC Classes  ?

• H04N 5/235 - Circuitry for compensating for variation in the brightness of the object
• G06T 7/70 - Determining position or orientation of objects or cameras
• G06T 7/194 - SegmentationEdge detection involving foreground-background segmentation
• G06V 20/13 - Satellite images

Abstract

A method for accurately and efficiently calculating a dense ephemeris of a high-eccentricity orbit is provided. With respect to the ephemeris calculation of the high-eccentricity orbit, the method constructs uneven interpolation nodes through time transformation and interpolates by an interpolation polynomial based on uneven interpolation nodes to obtain a dense ephemeris, which significantly improves the calculation efficiency and accuracy. Based on a large-scale numerical experiment, the method derives an optimal universal value (that is, 0.3) of a transformation parameter for all orbital eccentricities and various interpolation polynomials. In the case of using the optimal universal value of the transformation parameter δ, the method further verifies the Hermite interpolation polynomial as the preferable one among various interpolation polynomials.

IPC Classes  ?

• B64G 3/00 - Observing or tracking cosmonautic vehicles
• G06F 17/13 - Differential equations
• G01S 19/27 - Acquisition or tracking of signals transmitted by the system creating, predicting or correcting ephemeris or almanac data within the receiver

Abstract

A grating- and fiber-coupled multi-beam coherent receiving system in a mid- and far-infrared band includes a mid- and far-infrared local oscillator signal source, a phase grating, a multi-beam fiber coupling system, a 2×2 pixel mid- and far-infrared superconducting HEB mixer, a multi-channel DC bias source, a multi-channel cryogenic low-noise amplifier, and a room-temperature intermediate-frequency and high-resolution spectrum processing unit. In a 2×2 multi-beam superconducting receiving system, an echelle grating and a cryogenic optical fiber are used to distribute and couple the local oscillator signal, and the mid- and far-infrared band high-sensitivity superconducting HEB mixer is used to realize efficient local oscillator signal distribution and coupling, and ultimately achieve high-sensitivity and high-resolution multi-beam spectrum reception in the mid- and far-infrared band.

IPC Classes  ?

• H04B 10/61 - Coherent receivers

Abstract

A rapid processing method applicable to large eccentricity orbit dense ephemeris precision calculation. For large eccentricity orbit calculation, a novel method for constructing an interpolation base point by means of time transformation is provided, a constructed non-uniform interpolation base point matches an interpolating polynomial for interpolation to obtain a dense ephemeris, and the technical solution can significantly improve calculation efficiency and accuracy. According to the method, on the basis of large-scale numerical experiments, an optimal universal numerical value of time transformation parameters corresponding to different orbital eccentricities and multiple interpolation polynomials is given as 0.3. In addition, under the condition that the optimal universal numerical value is taken for the time transformation parameters, it is a good method to determine the Hermite interpolating polynomial by comparing calculation efficiency of the multiple interpolating polynomials.

IPC Classes  ?

• G06F 17/11 - Complex mathematical operations for solving equations
• G06F 17/13 - Differential equations

Abstract

A real-time celestial positioning and metering method for the space debris based on automatic pointing measurement. The method comprises: generating a theoretical star chart; obtaining the astrology of a star and the space debris; generating an actually detected star chart; matching the theoretical star chart and the actually detected star chart; measuring the pointing and image surface rotation; retrieving the star; preferably selecting a film model; calculating a metering model; and performing celestial positioning and metering of the space debris. The method can automatically preferably select the film model according to the observation field of view size, and automatically measure an image center pointing and image surface angle of rotation according to the time given on an image to automatically match the theoretical coordinate and the actually measured coordinate of the star, and automatically match the gray scale value of the star on the image and the theoretical magnitude of the star, thereby achieving real-time celestial positioning and metering of the space debris.

IPC Classes  ?

• G01C 21/02 - NavigationNavigational instruments not provided for in groups by astronomical means
• G01C 25/00 - Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass

Abstract

The present invention provides a mid-far infrared band grating and fiber coupling multi-beam coherent reception system, which is used for implementing multi-beam coherent signal detection in a mid-infrared beam. In a 2×2 multi-beam superconducting reception system, local oscillator signals are allocated and coupled by using a stepped grating and a low-temperature fiber, and a mid-far infrared band high-sensitivity hot-electronbolometer (HEB) is used to realize the high-efficiency allocation and coupling of the local oscillator signals, and finally, mid-far infrared band high-sensitivity high-resolution multi-beam spectrum reception is achieved. The present invention does not need to use a hyper-hemispherical lens of the HEB to couple the local oscillator signals, and directly aligns an output end of the fiber with one side of a chip of the HEB, thereby realizing the isolation between the local oscillator signals and detection signals, and effectively loading the local oscillator signals. In this way, the present invention reduces the loss of detection signals, improves the sensitivity of the reception system, and realizes, in conjunction with a multi-image element stepped grating, a mid-far infrared band effective and feasible multi-beam local oscillator allocation and loading system, being easy to expand to a large-scale array.

IPC Classes  ?

• H04B 10/61 - Coherent receivers

Abstract

A method for constructing a free trajectory at a specified launching elevation angle. The method comprises: firstly, sequentially calculating earth-fixed rectangular coordinate vectors of a launching point and a target point, the difference between a geodetic latitude and a geocentric latitude, a horizontal included angle, and the difference between the ratio of geocentric radial modes of point A and point B and one; in an iterative initial state and a two-body motion model, solving variables such as the launching speed of a forward trajectory or a reverse trajectory in an orbit coordinate system, the launching speed of the forward trajectory or the reverse trajectory in an earth-fixed coordinate system, a trajectory/orbit root number σ, and a time of flight, wherein the newly solved time of flight is T*; and enabling T = T*, repeatedly and iteratively calculating the launching speed, etc. of a missile, ending iteration until |T - T*t22 term of the Earth's gravitational field, and then, all trajectories from launching points to target points are obtained by means of traversing launching elevation angles.

IPC Classes  ?

• G06F 17/10 - Complex mathematical operations

Abstract

Disclosed in the present invention is a space debris observation method based on alternation of different exposure times of a CCD camera. A CCD camera is controlled to consecutively perform alternate acquisition of short exposure images and long exposure images according to given exposure times; detection and astronomical positioning of low, medium and high orbit space debris are achieved by processing odd-frame short exposure images; detection of medium and high orbit space debris is achieved by processing even-frame long exposure images, and astronomical positioning of medium and high orbit debris detected in a current frame is achieved by using negative film model coefficients of adjacent odd-frame images; moreover, in a search observation mode, precise astronomical positioning of low, medium and high orbit space debris is achieved by means of a multipoint adjustment method and the negative film model coefficients of adjacent odd frames. The present invention can achieve simultaneous detection and precise astronomical positioning of all-orbit space debris, thereby improving observation efficiency of an observation device and guaranteeing detection precision of the observation device for all-orbit space debris.

IPC Classes  ?

• G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints