# US 10,310,072 B2 · Method of walk-through security inspection and system thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,072 B2 - Document ID: US10310072B2 - Status: Granted - Kind: B2 - Application number: 16/080,060 - Filed: 2017-10-26 - Published: 2019-02-28 - Granted: 2019-06-04 - Earliest claimed: 2016-10-30 - Assignees: Camero-Tech Ltd. - Applicants: Camero-Tech Ltd. - Inventors: Ron Daisy; Amir Beeri - Web page: https://patentgrep.com/patent/US10310072B2 ## CPC - G01S 13/0209: {Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband} - G01N 23/046: using tomography, e.g. computed tomography [CT] - G01S 13/887: {for detection of concealed objects, e.g. contraband or weapons} - G01V 3/12: operating with electromagnetic waves {(operating with millimetre waves G01V8/005)} - G01S 13/89: for mapping or imaging - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract There are provided a security inspection system comprising ultra-wideband transmitters (104) and receivers (103) and a method of security inspection. The method comprises scanning a walk-through inspection space (200) along with an inspected person passing there through to yield collected data informative of scattered signals in association with respective channels, wherein the ultra-wideband transmitters and receivers are arranged at both sides of the inspection space. The method further comprises dividing the inspection space into a plurality of subspaces such that each voxel in the inspection space belongs to one and only one subspace, providing image reconstruction separately for each subspace of the plurality of the subspaces, wherein image reconstruction for voxels residing in a given subspace is provided using collected data corresponding to a set of channels selected for the given subspace in accordance with predefined rules; and using image reconstruction results to detect a concealed object. ## Claims ### Claim 1 A method of security inspection by a security inspection system comprising ultra-wideband transmitters and receivers, the method comprising: scanning a walk-through inspection space along with an inspected person passing there through to yield collected data informative of scattered signals in association with respective channels, wherein the ultra-wideband transmitters and receivers are arranged at both sides of the inspection space; upon dividing the inspection space into a plurality of subspaces such that each voxel in the inspection space belongs to one and only one subspace, providing image reconstruction separately for each subspace of the plurality of the subspaces, wherein image reconstruction for voxels residing in a given subspace is provided using collected data corresponding to a set of channels selected for the given subspace in accordance with predefined rules, wherein selecting the set of channels comprises: calculating one or more parameters of specular points of channels reflected by a virtual equi-area tessellated sphere co-centric with a given subspace; identifying channels with the calculated one or more parameters matching channel-dropping criteria defined to the given subspace thereby giving rise to omitted channels; and generating a set of channels selected for the given subspace, the generating comprising excluding the omitted channels from further processing for image reconstruction; and using image reconstruction results to detect a concealed object. ### Claim 2 (depends on 1) The method of claim 1, wherein the generating further comprises matching the amount of channels remaining after excluding the omitted channels to a predefined for the given subspace number Nch of selected channels and adding dummy channels when the amount of remaining channels is less than Nch. ### Claim 3 (depends on 1) The method of claim 1, wherein the generating further comprises matching the amount of channels remaining after excluding the omitted channels to a predefined for the given subspace number Nch of selected channels and excluding a part of remaining channel from further processing for image reconstruction when the amount of remaining channels is more than Nch, wherein the part of remaining channel is excluded so as to maximize uniformity of coverage of a predefined part of the virtual sphere by specular points of non-excluded channels. ### Claim 4 (depends on 1) The method of claim 1, wherein the channel-dropping criteria comprise one or more criteria selected from a group consisting of: absence of a specular point on a respective sphere, reflection angle more than a predefined maximal reflection angle, and max bore-sight angle for a receiver and/or for a transmitter more than a predefined maximal bore-sight angle. ### Claim 5 (depends on 1) The method of claim 1, wherein the channel-dropping criteria comprise one or more criteria related to location of respective specular points on the sphere. ### Claim 6 (depends on 1) The method of claim 1, wherein the channel-dropping criteria is configured the same for each subspace. ### Claim 7 (depends on 1) The method of claim 1, wherein inspection subspaces are combined in two or more groups corresponding to location in the inspection space, and channel-dropping criteria defined to subspaces in a given group comprise at least one criteria with values being common for all subspaces in the given group and being different for subspaces in another group. ### Claim 8 (depends on 7) The method of claim 7, wherein the at least one criteria with values being common for all subspaces in the given group, is related to location of specular points on respective spheres. ### Claim 9 (depends on 7) The method of claim 7, wherein the at least one criteria with values being common for all subspaces in the given group, is indicative of transmitter and receiver of a respective channel located at different sides of inspection space with regard to a walk direction. ### Claim 10 A security inspection system comprising a signal acquisition unit operatively connected to data processing unit, wherein: the signal acquisition unit comprises a plurality of ultra-wideband transmitters and receivers arranged at both sides of a walk-through inspection space and configured to scan the inspection space along with an inspected person passing there through, to yield collected data informative of scattered signals in association with respective channels; the data processing unit is configured: upon dividing the inspection space into a plurality of subspaces such that each voxel in the inspection space belongs to one and only one subspace, to provide image reconstruction separately for each subspace of the plurality of the subspaces, wherein image reconstruction for voxels residing in a given subspace is to be provided using collected data corresponding to a set of channels selected for the given subspace in accordance with predefined rules, wherein selecting the set of channels comprises: calculating one or more parameters of specular points of channels reflected by a virtual equi-area tessellated sphere co-centric with a given subspace; identifying channels with the calculated one or more parameters matching channel-dropping criteria defined to the given subspace thereby giving rise to omitted channels; generating a set of channels selected for the given subspace, the generating comprising excluding the omitted channels from further processing for image reconstruction and; to use image reconstruction results for detecting a concealed object. ### Claim 11 (depends on 10) The security inspection system of claim 10, wherein the generating further comprises matching the amount of channels remaining after excluding the omitted channels to a predefined for the given subspace number Nch of selected channels and adding dummy channels when the amount of remaining channels is less than Nch. ### Claim 12 (depends on 10) The security inspection system of claim 10, wherein the generating further comprises matching the amount of channels remaining after excluding the omitted channels to a predefined for the given subspace number Nch of selected channels and excluding a part of remaining channel from further processing for image reconstruction when the amount of remaining channels is more than Nch, wherein the part of remaining channel is excluded so as to maximize uniformity of coverage of a predefined part of the virtual sphere by specular points of non-excluded channels. ### Claim 13 (depends on 10) The security inspection system of claim 10, wherein the channel-dropping criteria comprise one or more criteria selected from a group consisting of: absence of a specular point on a respective sphere, reflection angle more than a predefined maximal reflection angle, and max bore-sight angle for a receiver and/or for a transmitter more than a predefined maximal bore-sight angle. ### Claim 14 (depends on 10) The security inspection system of claim 10, wherein the channel-dropping criteria comprise one or more criteria related to location of respective specular points on the sphere. ### Claim 15 (depends on 10) The security inspection system of claim 10, wherein the channel-dropping criteria is configured the same for each subspace. ### Claim 16 (depends on 10) The security inspection system of claim 10, wherein inspection subspaces are combined in two or more groups corresponding to location in the inspection space, and channel-dropping criteria defined to subspaces in a given group comprise at least one criteria with values being common for all subspaces in the given group and being different for subspaces in another group. ### Claim 17 (depends on 16) The security inspection system of claim 16, wherein the at least one criteria with values being common for all subspaces in the given group, is related to location of specular points on respective spheres. ### Claim 18 (depends on 16) The security inspection system of claim 16, wherein the at least one criteria with values being common for all subspaces in the given group, is indicative of transmitter and receiver of a respective channel located at different sides of inspection space with regard to a walk direction.