66 results about "Passive probing" patented technology

A WLAN (108) includes a first access point (104) for providing wireless service within a first coverage area, a second access point (106) for providing wireless service within a second coverage area and programmed to transmit probe responses, and a wireless communications unit (102) located within the first coverage area and operating on the wireless service of the first access point (104). The communications unit (102) is programmed to monitor, or passively probe, for the probe responses, or is instructed by the first access point (104) on when to monitor for the probe responses, transmitted by the second access point (106). By executing such passive probing, the communications unit (102) may make handover decisions for switching between the wireless service of the first access point (104) to the wireless service of the second access point (106) based on access point data included in the probe responses.

A system and method for a request failover mechanism on a load balancing system. The method may include a load balancer selecting a node from among a plurality of nodes associated with the load balancer to handle a request. The load balancer may limit selection to those nodes not known by the load balancer to be inactive. The load balancer may then determine if the selected node is able to service the request. In response to determining the selected node is unable to handle the request, the load balancer may select another node from among the plurality of nodes not known by the load balancer to be inactive. In various embodiments, the load balancer may mark nodes which are unable to service requests as inactive. The load balancer may determine if nodes are able to service requests by various methods, including active probing, passive probing, and dummy probing.

The invention relates to a passive radar detection method by use of synergistic or asynergistic satellite signals to detect low altitude targets, belonging to the technical field of space technology, which comprises a satellite and a ground passive radar system; wherein, the system comprises a plurality of detection stations and a data processing station, and interactive communications are conducted between the detection stations and the data processing station by means of radio or optical fiber transmission method. The signals, expanded frequency measurement codes and the signals reflected on low altitude aircrafts by and of the satellite, especially high radiation power satellite, are received by the detection station receivers of the passive radar with high sensitivity. After correlation, the path difference between the direct radiation signals of the satellite and the signals from the same source reflected by the low altitude targets can be derived; then, a group of passive detection equations can be established; the solutions can be obtained simultaneously. And a three-dimensional position coordinate of the low or super low altitude targets can be thus acquired. The invention has the advantages of huge detection area, small blind area, the capability of detecting low or super low aircrafts like cruise missiles and super low altitude airplanes passively at long range, and extensive application value for military use.

The invention discloses a passive detection system for detecting a low-altitude target by using navigation radar signals and relates to the field of passive radars. The passive detection system comprises a non-cooperative navigation radar, a passive receiving system, a signal information processing module and a geographic information module used for displaying positioning results. The invention further discloses a method for passively positioning the low-altitude target by using the navigation radar. The method includes steps that: 1 the passive receiving system measures arrival angles of a direct arrival signal and a target echo; 2 direct arrival pulses are adopted to estimate the azimuth angle of a navigation radar emitting antenna scanning from a direct arrival path to a target reflection path; 3 the signal information processing module is adopted to obtain time delay of the target echo relative to the direct arrival signal; 4 measurement is obtained, a triangle formed by the navigation radar, the target and the passive receiving system is solved and three-dimensional coordinates of the target are obtained; and 5 the target position is given on an electronic map. The passive detection system and method have the capability of detecting the low-altitude target for maintaining electromagnetic silence and can achieve situation monitoring and early warning.

The invention relates to an active positioning method based on a reliable sound path and target multipath echo. For solving disadvantages of a passive detection method based on a reliable sound path, a single base active sonar is proposed to arrange under the critical depth, the reliable sound path is utilized to irradiate a target, the target multipath echo is further acquired, and the final target positioning result is acquired. The method is advantaged in that the basic principle and an enforcement scheme are verified through computer value simulation, as proved by the result, effective target positioning in the deep sea environment can be realized.

In one embodiment, during network operation, it is dynamically determined whether to change from passive probing of communication path metrics to active probing of communication path metrics.

The invention relates to a dual-waveband active-polarization target identification system for observing a sea fog environment and belongs to the technical field of optical information processing. The system comprises a light source, a first light splitting system, an active polarization transmission system, a collimating and beam-expanding system, a second light splitting system, a dual-waveband polarization detection system, a joint-transform power spectrum generation system, a related peak generation system, a receiving system I, a receiving system II and a computer processing and controlling system. The detection principle of the traditional joint transform correlator is adopted, the advantages of polarization and infrared technologies in target detection are combined, and the existing passive detection mode is converted into an active polarization detection mode, so that the probability of target detection is increased. In the transmission system, a light splitting mode is adopted, and only one light source is adopted to complete active detection and target identification; in the receiving systems, a rotary control turntable is adopted, the system light path is simplified, the number of devices used by the systems is least on the premise of guaranteeing the quality of target identification, the operation is simple and convenient, and the implementation is easy.

The invention belongs to the acoustic vector sensor array signal processing field, and more specifically relates to an acoustic vector circular array source number detection method based on characteristic value multiple threshold correction which is applied to underwater target remote passive detection. The method comprises establishing an acoustic vector circular array signal receiving model, obtaining acoustic vector circular array receiving acoustic pressure data, radial vibration velocity data and tangential vibration velocity, constructing a covariance matrix of acoustic vector circular array acoustic pressure and vibration velocity combined treatment, and decomposing characteristic values; and performing multiple threshold division treatment on a characteristic value set obtained by decomposing the covariance matrix to obtain a signal and noise corresponding characteristic value set. The method dynamically integrates an information theory detection method based on characteristic value multiple thresholds and the sound anti-noise performance of an acoustic vector circular array, obviously reduces the signal to noise ratio threshold of a detection algorithm, and overcomes the disadvantages that traditional detection methods such as MDL, diagonal loading MDL, and GDE are more sensitive to noise characteristic value change.

The invention relates to a detection warning instrument. The detection warning instrument has the advantages that a multi-channel information processing system and an intelligent early warning system are arranged, multiple detection techniques, such as ultralow-frequency electromagnetic wave, ultrawide-frequency radar, sound wave/vibration, infrared rays and terahertz radar, are integrated, and a passive detection method and an active detection method are combined, so the detection warning function on life targets and non-life targets is realized; the false target excluding capability is improved, the accuracy and positioning speed of the detected target are improved, and the requirements of complicated environment conditions and task conditions are met.

The embodiment of the invention discloses a network range asset information collection method and device based on active and passive combination, and relates to the field of network security, and themethod comprises the steps: analyzing and recording fingerprint features, and constructing an operating system fingerprint comparison sample library and a service application or component fingerprintcomparison sample library; configuring a networking host in a detection network target range environment; collecting operating system information and service application or component information of the networked host in an active detection mode to form asset information data; collecting operating system information and service application or component information of the networked host in a passivedetection mode to form asset information data; and integrating asset information data acquired by active detection and passive detection to form a complete network range asset information list.

The invention provides an underwater protection system for coastal aquaculture and an operating method therefor. The protection system comprises monitors (100) and a data center (200), wherein the monitors are fixedly arranged on underwater culture net cages (300) or directly fixed in water in a suspended manner, and wireless communication modules are correspondingly arranged on the monitors and the data center separately so as to achieve wireless communication connection between the monitors and the data center; and the data center further comprises a warning module (220) and controls the warning module to alarm when wireless signals received from the monitors by the data center are in line with alarm conditions. According to the underwater protection system and the operating method therefor, multipoint, real-time and uninterrupted offshore net cage monitoring and automatic alarming are achieved through wireless communication connection on the basis of a submarine sound signal passive detection principle, and thus, the real-time monitoring and warning of aquaculture net cages of an entire seashore is achieved; and the protective range is large, the efficiency is high, the safety and reliability are good, and the cost is low.

The invention discloses a target positioning method and system of full passive detection. The method includes co-station deploying a photoelectric detection system and a radio detection system; fusing, by the matching of an azimuth, the azimuth information and the elevation angle information of a target acquired by the photoelectric detection system of a host station and the azimuth information and the frequency point information of the target acquired by the radio detection system, so as to obtain the azimuth information, the elevation angle information and the frequency point information ofthe target; for the azimuth information, the elevation angle information and the frequency point information detected by different stations, performing target registration by the frequency point information of the target so that according to the location information of different stations, the photoelectric detection systems of different stations performs cross-positioning calculation on the azimuth information and the elevation angle information acquired by the target at the frequency point, and obtains the distance information between the photoelectric detection system of different stations and the target, thereby obtaining the azimuth information and the elevation angle information of the target and achieving target positioning.

The invention discloses an optical axis monitoring method and device for a high-precision active/ passive detection system. The device comprises a laser emission system, an optical axis separation assembly, a common telescope, an optical axis monitoring camera, a passive imaging system and a laser reception system. By utilizing a characteristic that an included angle between prism incident light and prism emergent light in an incident plane is only related to the an included angle of a prism reflecting surface, and by means of introducing an optical axis separation component and the optical axis monitoring camera and the like to the high-precision multi-optical axis active/passive composite detection system, a relative relation between a laser emission optical axis and a passive imaging system optical axis is established, so that variation conditions of each optical axis can be monitored in real time in the working process of the high-precision active/passive detection system, and on the basis of the obtained optical axis variation data, detection data can be corrected in the following data processing. The method and the device have the advantages of high optical axis monitoring sensitivity, good self optical axis stability and mature processing and adjusting technology and the like, and can be widely applied to an airborne and satellite-borne high-precision active/passive compound detection optoelectronic system.

The invention discloses a universal UUV (Unmanned Underwater Vehicle) underwater target detection simulation method and system. The method comprises the following steps that: receiving a selected detection mode, wherein the detection mode comprises active detection and passive detection; if the active detection is selected, starting the active detection, and obtaining a target detection result; and otherwise, starting the passive detection to obtain a target detection result. By use of the method and the system, the simulation research service of UUV capacity building can be provided, and through the modeling of typical underwater sound detection equipment and a detection process, a standardized and generalized underwater target detection model is provided.

Methods and apparatus are disclosed for wirelessly communicating among integrated circuits and/or functional modules within the integrated circuits. A semiconductor device fabrication operation uses a predetermined sequence of photographic and/or chemical processing steps to form one or more functional modules onto a semiconductor substrate. The functional modules are coupled to an integrated waveguide that is formed onto the semiconductor substrate and/or attached thereto to form an integrated circuit. The functional modules communicate with each other as well as to other integrated circuits using a multiple access transmission scheme via the integrated waveguide. One or more integrated circuits may be coupled to an integrated circuit carrier to form Multichip Module. The Multichip Module may be coupled to a semiconductor package to form a packaged integrated circuit.

The invention discloses a non-contact detection device and method for electric wires embedded in a wall body, and belongs to the technical field of electric wire detection. The detection device comprises an irradiation source, an optical mechanical scanning device, a millimeter wave detector, a signal processing circuit and an image display module, wherein the irradiation source comprises a noiseirradiation source and a microwave emitting antenna; the optical mechanical scanning device is used for carrying out two-dimensional beam scanning on the wall body to obtain millimeter waves emitted by the electric wires embedded in the wall body; the millimeter wave detector performs amplification and detection processing on the received millimeter waves and outputs the processed millimeter wavesto the signal processing circuit for performing processing; and a periodic maximum equiamplitude signal is obtained, so that position information and/or trend information of the electric wires is obtained and is displayed in the image display module. The invention further provides the detection method, which comprises a passive detection mode and/or an active detection mode. According to the detection device and method, the electrified and non-electrified electric wires embedded in the wall body can be detected in a non-contact mode.

The invention discloses a wireless network detection method suitable for a high-speed mobile environment, which is a method combined with an active detection technology and a passive detection technology for judging change of link quality according to a detection result and for dynamically adjusting the detection strategy self-adaptively. Operation steps of the method are as follows: initiating detection, integrating a detection result and adjusting a detection strategy. Due to the fact that the active detection technology and the passive detection technology are combined, the defect that a certain technology is used independently is overcome; the detection period is self-adaptively adjusted according to the change of the link quality, so that the characteristic that the network environment is complex and variable in a high-speed mobile environment is achieved; the problem that the real-time performance and accuracy of wireless network detection of the high-speed mobile network cannotbe guaranteed is solved; and a reliable basis for network resource scheduling in the high-speed mobile environment is provided.

The invention relates to a satellite-borne active and passive integrated detection device. The satellite-borne active and passive integrated detection device comprises a reflecting surface part, an active part, a passive part, an expansion mechanism and a data processing system, wherein the reflecting surface part is shared by the active part and the passive part, the passive part is arranged on the active part and is arranged at the top of a satellite loading cabin by the expansion mechanism, and the data processing system is arranged in a satellite. By effective combination of active detection and passive detection, satellite-borne detection and data fusion inversion are expanded, the defects of high detection accuracy while low space resolution (generally dozens of kilometers dimension)of passive detection and the defects of high space resolution (generally several meters to several kilometers dimension) while low accuracy of active detection can be overcome, and high-space resolution and high-accuracy soil humidity and freezing and thawing state detection can be achieved.

The invention relates to the fields of hydroacoustic engineering, oceanographic engineering and sonar technology, in particular to a method for increasing passive sonar operating distance by means of shallow sound field airspace characteristics. The method is suitable for shallow sea target passive detection. The method comprises the steps of placing a short vertical array in a shallow water acoustic channel, establishing conventional beamformer weight vector by means of the spatial aperture of the short vertical array, acquiring the reception directional response of the short vertical array, obtaining the vertical reception directivity to noise data and a remote sound source of the short vertical array, and reasonably adjusting the directivity of the short vertical array to obtain a higher output signal to noise ration by comparing the vertical reception directivity to noise data with the vertical reception directivity to the remote sound source. According to the method, the difference between the reception directional response to ambient sea noise and the reception directional response to a remote sound source radiator signal of the vertical array in shallow sea is fully utilized, the output signal to noise ration of a received signal is increased, and then the operating distance of a passive sonar is increased.