Abstract:
Provided are a system and method for estimating position of lost mobile terminal and a mobile terminal. The system for estimating position of lost mobile terminal includes a plurality of base stations and a computing apparatus. Each of the base stations transmits an activation signal, receives a terminal ID from the mobile terminal in response to the activation signal, and transmits a reception time of the terminal ID and the terminal ID. The computing apparatus estimates a position of the mobile terminal corresponding to the terminal ID on the basis of the reception time and a position of each of the base stations.
Abstract:
Provided are an apparatus and method for measuring an antenna gain. The apparatus includes an antenna gain-to-noise-temperature (G/T) ratio calculator for calculating a G/T ratio using a reception noise power measured while an antenna is tracking the sun, a noise temperature measurer for measuring a noise temperature when a signal is transmitted or received through the antenna, and an antenna gain calculator for calculating an antenna gain using the calculated G/T ratio and the measured noise temperature. Thus, it is possible to easily measure the antenna gain of a ground station without a reference antenna or a satellite-mounted device capable of functioning as a reference antenna.
Abstract:
Provided is an antenna aligning apparatus for near-field measurement, which can perform alignment between a measurement target antenna and a probe antenna precisely by using an antenna pattern and detecting coordinates of the least error. The antenna aligning apparatus includes: a receiving antenna, a signal dividing means, a vertical polarization port, a horizontal polarization port, a first amplitude/phase detector, a second amplitude/phase detector, a coordinate determining means for, and a position adjuster.
Abstract:
Provided are an apparatus and method for determining a diameter of a reflector antenna. The apparatus includes a setting unit for setting up electrical characteristic values of the reflector antenna upon receipt thereof from outside, a parameter input unit for receiving a frequency, an antenna diameter variable value, antenna efficiency, Edge Taper (ET), and an Edge Of Coverage (EOC) angle as parameters for each of multiple frequencies to be accommodated in the reflector antenna, a graph generator for generating, on one rectangular coordinate, a graph representing the relationship between an antenna diameter and EOC directivity with respect to the EOC angle based on the parameters for each frequency received through the parameter input unit, an antenna diameter determination unit for determining an antenna diameter that simultaneously meets the preset EOC directivities for the frequencies to be accommodated in the reflector antenna by using the graph generated by the graph generation unit, and a graph output unit for mapping and outputting the graph generated by the graph generation unit on one rectangular coordinate with an antenna diameter axis and an EOC directivity axis to thereby represent the antenna diameter determined by the antenna diameter determination unit on the graph.
Abstract:
Provided are an apparatus and method for determining a diameter of a reflector antenna. The apparatus includes a setting unit for setting up electrical characteristic values of the reflector antenna upon receipt thereof from outside, a parameter input unit for receiving a frequency, an antenna diameter variable value, antenna efficiency, Edge Taper (ET), and an Edge Of Coverage (EOC) angle as parameters for each of multiple frequencies to be accommodated in the reflector antenna, a graph generator for generating, on one rectangular coordinate, a graph representing the relationship between an antenna diameter and EOC directivity with respect to the EOC angle based on the parameters for each frequency received through the parameter input unit, an antenna diameter determination unit for determining an antenna diameter that simultaneously meets the preset EOC directivities for the frequencies to be accommodated in the reflector antenna by using the graph generated by the graph generation unit, and a graph output unit for mapping and outputting the graph generated by the graph generation unit on one rectangular coordinate with an antenna diameter axis and an EOC directivity axis to thereby represent the antenna diameter determined by the antenna diameter determination unit on the graph.
Abstract:
Provided is a satellite ground control system and method based on a communication satellite. The system includes: a communication satellite link means for monitoring and controlling a system device and transmitting remote measurement data and a process result to the central control station; an interface for analyzing the command, transmitting the command to a processing means and transmitting remote measurement data and a process result to the communication satellite link means; a satellite operating means for receiving a command from the interface, transforming the command into a remote command and transmitting remote measurement data to the interface; and a control satellite link means for transmitting the received remote command, receiving the remote measurement data, transmitting the remote measurement data to the satellite operating means, and transmitting a process result of monitor and control of a corresponding system device to the interface.
Abstract:
The present invention relates to an emergency position indicating radio beacon (EPIRB) terminal for confirming positions of ships and rescuing the ships during a marine disaster in a marine search and rescue system and an apparatus and a method for monitoring an operating state of the EPIRB terminal. The EPIRB terminal comprises: a sensor unit for sensing the sinking of a ship in which the EPIRB terminal is provided; a generation unit for generating a distress message corresponding to the sensed result of the sensor unit; and a transmission unit for broadcasting a distress signal including the distress message. The sensor unit comprises: a water-pressure sensor for outputting a water-pressure detection signal by sensing the water pressure in the inside of the ship; a moisture sensor for outputting a moisture detection signal by sensing the moisture inside the ship; and a separation sensor for outputting a separation detection signal by sensing the separation of the EPIRB terminal from the ship. The sensor unit outputs a generating request signal of the distress message to the generation unit by normally sensing the sinking of the ship when the water-pressure detection signal, the moisture detection signal, and the separation detection signal are outputted.
Abstract:
Provided is a Global Positioning System (GPS) signal repeater and a GPS receiver of a stationary orbit satellite, and a method for positioning a stationary orbit satellite using the same. The GPS signal repeater includes: a GPS receiver for receiving an L-band GPS signal transmitted from a GPS satellite; a low-noise amplifier for removing noise of the received L-band GPS signal and maximally amplifying a desired signal; a frequency transformer for transforming the amplified L-band GPS signal into an up-link frequency band; a high power amplifier for amplifying the transformed up-link frequency band GPS signal; and a transmitter for transmitting the amplified signal to a stationary orbit satellite.
Abstract:
Provided are an apparatus for searching a distress signal and a controlling method thereof. The apparatus for searching a distress signal includes: a beacon receiver receiving the distress signal transmitted from a distress beacon apparatus of a COSPAS-SARSAT system; a decoder decoding the distress signal to acquire distress information; and a display unit displaying the acquired distress information. The apparatus for searching a distress signal is used by a search and rescue team.
Abstract:
A mobile apparatus for tracking a satellite, includes: a mobile unit; a GPS receiving unit mounted on the mobile unit that generates position coordinates of the mobile unit; a level meter mounted on the mobile unit that adjusts the mobile unit in horizontal and obtains a tilt angle of the mobile unit; an antenna unit mounted on the mobile unit and being adjusted to the true north direction according to the position coordinates. Further, the mobile apparatus for tracking a satellite includes position tracking control unit mounted on the mobile unit that temporarily stops the mobile unit when tracking a position of the satellite, adjusts the mobile unit in horizontal by the level meter and aligns the position coordinates and the tile angles to correct current position information of the mobile unit.