# US 2013/0155807 A1 · Method for determining positions of sensor streamers during geophysical surveying > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155807 A1 - Document ID: US20130155807A1 - Status: Published application - Kind: A1 - Application number: 13/327,404 - Filed: 2011-12-15 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: PGS Geophysical AS - Inventors: Gustav Göran Mattias SÜDOW; John FALKENBERG; Bengt Richard FINNOEN - Web page: https://patentgrep.com/patent/US20130155807A1 ## CPC - G01V 1/3835: {measuring position, e.g. by GPS or acoustically} - 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 A method for determining geodetic position of at least one point on a geophysical sensor streamer towed by a vessel in a body of water includes determining geodetic positions of a plurality of locations along a first geophysical sensor streamer towed at a first depth in the body of water. A lateral offset is caused between the first geophysical sensor streamer and a second geophysical sensor streamer towed at a second depth in the body of water. A distance is measured between at least two selected points along the first geophysical sensor streamer and a selected point along the second geophysical sensor streamer. A depth is measured at at least one point along the second geophysical sensor streamer. A geodetic position is determined at a selected point along the second geophysical sensor using the depth measurement, a direction of the lateral offset and the measured distances. ## Claims ### Claim 1 A method for determining geodetic position of a point on a second geophysical sensor streamer towed in a body of water, comprising: determining geodetic positions of a plurality of locations along a first geophysical sensor streamer which is towed at a first depth in the body of water; causing a lateral offset between the first geophysical sensor streamer and the second geophysical sensor streamer; measuring a distance between the point on the second geophysical sensor streamer and each of a first and a second selected points along the first geophysical sensor streamer; measuring a second depth at the point on the second geophysical sensor streamer; calculating a depth difference from the first depth and the second depth; and determining a geodetic position at the point on the second geophysical sensor streamer using the depth difference, a direction of the lateral offset and the measured distances. ### Claim 2 (depends on 1) The method of claim 1 wherein the measuring the distances comprises measuring acoustic travel time between spaced apart acoustic range detection transceivers. ### Claim 3 (depends on 1) The method of claim 1 wherein the determining geodetic positions comprises: determining a geodetic position of at least two selected locations along the first geophysical sensor streamer; and determining a heading at the plurality of locations along the first geophysical sensor streamer. ### Claim 4 (depends on 3) The method of claim 3 wherein the heading comprises geomagnetic heading. ### Claim 5 (depends on 1) The method of claim 1 wherein the second geophysical sensor streamer comprises a plurality of electromagnetic sensors. ### Claim 6 (depends on 5) The method of claim 5 further comprising: determining a heading at selected positions along the second geophysical sensor streamer; and determining a geodetic position of at least some of the plurality of electromagnetic sensors using the determined geodetic position of the point on the second geophysical sensor streamer and the determined heading at selected positions along the second geophysical sensor streamer. ### Claim 7 (depends on 5) The method of claim 5 further comprising: measuring distances between selected pairs of positions along the first and second geophysical sensor streamers; and determining a geodetic position of at least some of the plurality of electromagnetic sensors using the determined geodetic position of the point on the second geophysical sensor streamer and the measured distances between the selected pairs of positions along the first and second geophysical sensor streamers. ### Claim 8 (depends on 1) The method of claim 1 wherein the first geophysical sensor streamer comprises a plurality of seismic sensors. ### Claim 9 (depends on 1) The method of claim 1 wherein the determining geodetic positions of a plurality of locations along the first geophysical sensor streamer further comprises detecting a geodetic position signal at an aft end of the first geophysical sensor streamer. ### Claim 10 (depends on 1) The method of claim 1 wherein the second geophysical sensor streamer and the first geophysical sensor streamer comprise seismic sensors. ### Claim 11 (depends on 1) The method of claim 1 wherein causing lateral offset between the first geophysical sensor streamer and the second geophysical sensor streamer is performed using a deflector. ### Claim 12 A method for geophysical surveying comprising: determining geodetic positions of a plurality of locations along a first geophysical sensor streamer which is towed at a first depth in the body of water; causing a lateral offset between the first geophysical sensor streamer and a second geophysical sensor streamer which is towed in the body of water; measuring a distance between a point on the second geophysical sensor streamer and each of a first and a second selected points along the first geophysical sensor streamer; measuring a second depth at the point on the second geophysical sensor streamer; calculating a depth difference from the first depth and the second depth; and determining a geodetic position at the point on the second geophysical sensor using the depth difference, a direction of the lateral offset and the measured distances; actuating at least one geophysical energy source disposed in the body of water; and detecting geophysical signals with one or more geophysical sensors disposed on at least one of the first and second geophysical sensor streamers. ### Claim 13 (depends on 12) The method of claim 12 wherein the measuring the distances comprises measuring acoustic travel time between spaced apart acoustic range detection transceivers. ### Claim 14 (depends on 12) The method of claim 12 wherein the determining geodetic positions comprises: determining a geodetic position of at least two selected locations along the first geophysical sensor streamer; and determining a heading at the plurality of locations along the first geophysical sensor streamer. ### Claim 15 (depends on 14) The method of claim 14 wherein the heading comprises geomagnetic heading. ### Claim 16 (depends on 12) The method of claim 12 wherein the second geophysical sensor streamer comprises a plurality of electromagnetic sensors. ### Claim 17 (depends on 16) The method of claim 16 wherein: the actuating at least one geophysical energy source comprises actuating an electromagnetic transmitter; and the detecting geophysical signals comprises detecting electromagnetic signals with the plurality of electromagnetic sensors. ### Claim 18 (depends on 16) The method of claim 16 further comprising: determining a heading at selected positions along the second geophysical sensor streamer; and determining a geodetic position of at least some of the plurality of electromagnetic sensors using the determined geodetic position of the point on the second geophysical sensor streamer and of the determined heading at selected positions along the second geophysical sensor streamer. ### Claim 19 (depends on 16) The method of claim 16 further comprising: Measuring distances between selected pairs of positions along the first and second geophysical sensor streamers; and determining a geodetic position of at least some of the plurality of electromagnetic sensors using the determined geodetic position of the point on the second geophysical sensor streamer and the measured distances between the selected pairs of positions along the first and second geophysical sensor streamers. ### Claim 20 (depends on 12) The method of claim 12 wherein the first geophysical sensor streamer comprises a plurality of seismic sensors. ### Claim 21 (depends on 20) The method of claim 20 wherein: the actuating at least one geophysical energy source comprises actuating a seismic energy source; and the detecting geophysical signals comprises detecting seismic signals with the plurality of seismic sensors. ### Claim 22 (depends on 12) The method of claim 12 wherein the determining geodetic positions of a plurality of locations along the first geophysical sensor streamer further comprises detecting a geodetic position signal at an aft end of the first geophysical sensor streamer. ### Claim 23 (depends on 12) The method of claim 12 wherein the second geophysical sensor streamer and the first geophysical sensor streamer comprise seismic sensors. ### Claim 24 (depends on 12) The method of claim 12 wherein causing lateral offset between the first geophysical sensor streamer and the second geophysical sensor streamer is performed using a deflector.