Abstract

The present invention belongs to the technical field of antennas and relates to a large-scale spaceborne deployment speed-controlled truss antenna. The truss antenna consists of a new large-scale deployable truss antenna and a flexible extension arm, wherein a reflector of the truss antenna is in the structural form of a parabolic cylinder; a deployment aperture of the truss antenna is expandable; and the flexible extension arm is of a retractable and extensible flexible structure. The flexible extension arm is connected to both a speed control system and a boundary of the truss antenna, such that the motion of the speed control system can be transmitted to the truss antenna during an antenna deployment process, and the speed of the antenna deployment process is then controlled. The antenna has the inherent advantages of the truss antenna, including a high storage ratio, reliable deployment, high repeatability, etc.; moreover, a deployment process and a deployment speed are controlled by means of the speed control system, thereby effectively avoiding the disadvantages of a large deployment impact, an uncontrollable deployment process, etc., of the truss antenna; and the truss antenna has wide application prospects.

IPC Classes  ?

• H01Q 1/08 - Means for collapsing antennas or parts thereof

Abstract

A distributed centerless space-based time reference establishing and maintaining system, comprising a space-based time reference constellation consisting of at least three space-based time reference satellites; at least three satellite-borne atomic clocks in a satellite-borne atomic clock group in each satellite are started to work; a single-satellite atomic time generation unit processes a start-up work atomic clock signal to generate a single-satellite atomic time physical signal; the single-satellite atomic time physical signal is sent to a space-based time reference generation unit and an internal laser/microwave time-frequency measurement comparison unit; a time-frequency measurement comparison link is formed between the internal laser/microwave time-frequency measurement comparison unit and internal laser/microwave time-frequency measurement comparison units of other space-based time reference satellites; inter-satellite time-frequency comparison and data transmission of the link are achieved by means of time-frequency measurement comparison; inter-satellite clock error comparison data is obtained by means of the internal laser/microwave time-frequency measurement comparison unit, and transmitted to the space-based time reference generation unit; and the space-based time reference generation unit obtains a space-based time reference physical signal according to the single-satellite atomic time physical signal and the inter-satellite clock difference comparison data.

IPC Classes  ?

• G04F 5/14 - Apparatus for producing preselected time intervals for use as timing standards using atomic clocks
• G04R 20/02 - Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS

Abstract

A laser velocimetry method and system are provided. In the method, an ultrashort pulse laser is subjected to temporal broadening, beam splitting and spectrum broadening in sequence to from a three-dimensional measurement space. When an object moves in the measurement space, a first signal light s_1, a second signal light s_2, a third signal light s_3 are generated, based on which velocity components vy, vx, and vx of the target object can be obtained, respectively, so as to obtain the velocity of the object in accordance with a formula of v=vx·i+vy·j+vz·k.

IPC Classes  ?

• G01S 17/58 - Velocity or trajectory determination systemsSense-of-movement determination systems
• G01S 7/481 - Constructional features, e.g. arrangements of optical elements

Abstract

A navigation method and system employing a low-orbit broadband Internet constellation. The method comprises: receiving a satellite navigation broadcast message or an accuracy message uploaded by a ground gateway station, and generating a first navigation signal according to the navigation broadcast message or the accuracy message (S101); generating a first communication signal according to a preset communication payload, and generating a second navigation signal according to the first communication signal and the first navigation signal, wherein the second navigation signal and the first communication signal are simultaneously distributed by means of sharing a frequency spectrum resource and a transmit channel (S102); and sending, to a terminal, the second navigation signal on a preset communication resource (S103), such that the terminal performs positioning, navigation and timing on the basis of the second navigation signal. The invention solves the technical problem in the art in which a navigation signal has poor anti-interference capability.

IPC Classes  ?

• G01S 19/44 - Carrier phase ambiguity resolutionFloating ambiguityLAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method
• G01S 19/21 - Interference related issues
• G01S 19/11 - Cooperating elementsInteraction or communication between different cooperating elements or between cooperating elements and receivers providing dedicated supplementary positioning signals wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters

Abstract

A moon navigation system based on an earth GNSS and a moon navigation enhancement satellite, which belongs to the technical field of navigation. By adding a small number (one or more) of satellites at an earth-moon Lagrangian point or a lunar orbit to broadcast a navigation signal having a measurement function, the observation geometry of a lunar user is improved in combination with an earth GNSS; and by establishing a bidirectional time synchronization link between a ground deep space station or a GNSS navigation constellation and a moon navigation enhancement satellite and a bidirectional time synchronization link between the moon navigation enhancement satellite and the lunar user, the problem of a clock error and a radial distance error of a user receiver being unable to be decoupled is solved, and the real-time positioning accuracy of the lunar user is improved. In addition, a lunar surface radio beacon is added in a key area on the moon to broadcast a navigation signal having a measurement function, so as to enhance the regional navigation performance. On the basis of adding a small number of moon navigation resources, the real-time performance and the accuracy of navigation and positioning for a lunar user can be greatly improved, and low- and medium-speed bidirectional communication between the ground and the lunar user, and low- and medium-speed bidirectional communication between lunar users are provided.

IPC Classes  ?

• G01C 21/24 - NavigationNavigational instruments not provided for in groups specially adapted for cosmonautical navigation

Abstract

A "cloud-end" architecture-based PPP-RTK enhancement method. First, massive high-precision user terminals around the globe perform PPP, and once the locations thereof converge, space correction information (comprising ionospheric correction numbers, and tropospheric correction numbers) based on the precise locations thereof is generated, and is uploaded to the "cloud" by means of a communication link. Then, in the "cloud", the space correction information from the massive user terminals is uniformly and intelligently processed to generate gridded space correction parameters, and low-orbit satellites are used to broadcast the space correction information to users in corresponding regions. The user terminals use the received correction information to perform PPP again, and upload the space correction information that is based on the precise locations thereof to the "cloud", which achieves PPP-RTK service around the globe by means of the intelligent evolution of the massive user terminals. The problem in which a traditional PPP-RTK service requires that a large number of ground monitoring stations be built, which is extremely costly and cannot achieve wide-area PPP-RTK service around the globe, is solved.

IPC Classes  ?

• G01S 19/33 - Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS
• G01S 19/37 - Hardware or software details of the signal processing chain

Abstract

Disclosed are a novel optical communication system and method applicable to a rotary joint. The system comprises: a light source, an optical expanded beam lens group, a wavelength spectroscope, a focus lens group, a receiving detector, a receiving unit, a transmission unit, and a conical cavity. A light source transmitted by the light source is collimated into a beam by means of the optical expanded beam lens group; the collimated beam is transmitted by means of the wavelength spectroscope having receipt/transmission separated; the transmitted beam is reflected into a circular beam by means of the surface of the conical cavity; the receiving unit receives the circular beam; a collimated light transmitted by the transmission unit is irradiated to the surface of the conical cavity, is reflected to the wavelength spectroscope by means of the conical cavity, then is reflected onto the focus lens group by means of the wavelength spectroscope; a beam converged by means of the focus lens group is transmitted to the receiving detector. According to the present invention, the bidirectional communication between a transmitted light ring and the optical receipt is performed without being affected by a rotary mechanism. Information interaction can be made for two servomechanisms of an inner stator and an outer stator or a rotary joint.

IPC Classes  ?

• H04B 10/116 - Visible light communication

Abstract

The present invention relates to a public cavity input multiplexer that is used to divide broadband signals into multi-channel narrowband signals according to the frequency and includes a public cavity and at least two channel filters. The public cavity is a broadband resonator that is used to input broadband signals, and is coupled with each of the channel filters respectively. In the input multiplexer of the present invention, no electric cable or waveguide and circulator are used for connection. The integrated design is achieved by establishing the public cavity and the channel filter, which reduces volume and mass, avoids the errors caused by influence on the circulator due to temperature change, enhances reliability, saves cost, and improves the electric performance. The design of the public cavity makes the input coupling accurate to calculate, convenient tuning and optimizes the consistency of channels.

IPC Classes  ?

• H01P 1/213 - Frequency-selective devices, e.g. filters combining or separating two or more different frequencies
• H01P 1/205 - Comb or interdigital filtersCascaded coaxial cavities
• H01J 23/24 - Slow-wave structures

Abstract

The present invention relates to a public cavity input multiplexer that is used to divide broadband signals into multi-channel narrowband signals according to the frequency and includes a public cavity and at least two channel filters. The public cavity is a broadband resonator that is used to input broadband signals, and is coupled with each of the channel filters respectively. In the input multiplexer of the present invention, no electric cable or waveguide and circulator are used for connection. The integrated design is achieved by establishing the public cavity and the channel filter, which reduces volume and mass, avoids the errors caused by influence on the circulator due to temperature change, enhances reliability, saves cost, and improves the electric performance. The design of the public cavity makes the input coupling accurate to calculate, convenient tuning and optimizes the consistency of channels.

IPC Classes  ?

• H04B 1/66 - Details of transmission systems, not covered by a single one of groups Details of transmission systems not characterised by the medium used for transmission for reducing bandwidth of signalsDetails of transmission systems, not covered by a single one of groups Details of transmission systems not characterised by the medium used for transmission for improving efficiency of transmission

Abstract

A public cavity input multiplexer that is used to divide broadband signals into multi-path narrowband signals according to the frequency is provided. The public cavity input multiplexer includes a public cavity and channel filters of at least two paths. The public cavity is a broadband resonator that is used to input broadband signals, and is coupled with channel filters of each path respectively.

IPC Classes  ?

• H04B 1/66 - Details of transmission systems, not covered by a single one of groups Details of transmission systems not characterised by the medium used for transmission for reducing bandwidth of signalsDetails of transmission systems, not covered by a single one of groups Details of transmission systems not characterised by the medium used for transmission for improving efficiency of transmission