CA1195762A - Submerged marine streamer locator - Google Patents
Submerged marine streamer locatorInfo
- Publication number
- CA1195762A CA1195762A CA000391897A CA391897A CA1195762A CA 1195762 A CA1195762 A CA 1195762A CA 000391897 A CA000391897 A CA 000391897A CA 391897 A CA391897 A CA 391897A CA 1195762 A CA1195762 A CA 1195762A
- Authority
- CA
- Canada
- Prior art keywords
- vessel
- streamer
- transponders
- acoustic
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
- G01V1/38—Seismology; Seismic or acoustic prospecting or detecting specially adapted for water-covered areas
- G01V1/3817—Positioning of seismic devices
- G01V1/3835—Positioning of seismic devices measuring position, e.g. by GPS or acoustically
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/87—Combinations of sonar systems
- G01S15/874—Combination of several spaced transponders or reflectors of known location for determining the position of a receiver
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Environmental & Geological Engineering (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Oceanography (AREA)
- Geophysics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Method and means are provided for determining the position of a submerged marine streamer towed behind an exploration vessel. An array of at least three trans-ponders secured to the ocean floor generate distinguish-able acoustic pulses upon a command signal from the ship.
These signals are received by hydrophones housed in the streamer and by the ship. The distance to each hydrophone may be triangulated from the data generated.
Method and means are provided for determining the position of a submerged marine streamer towed behind an exploration vessel. An array of at least three trans-ponders secured to the ocean floor generate distinguish-able acoustic pulses upon a command signal from the ship.
These signals are received by hydrophones housed in the streamer and by the ship. The distance to each hydrophone may be triangulated from the data generated.
Description
~s~
BACKGROUND OF THE INVENTION
Field of the Invention os The present invention finds principal applica-tion within the field of marine seismic exploration. More particularly, the invention is concerned with means for accurately determining the position of a towed marine seismic streamer.
Prior Art In marine seismic prospecting, an exploration vessel tows a seismic streamer having a plurality of pressure sensitive detectors, commonly referred to as hydrophones. A source of seismic energy, such as an air gun or an explosive charge, is used to propagate pressure waves through the water into the underlying sea floorO
Part of the energy will be reflected by subfloor geolog~
ical discontinuities and subsequently detected by the hydrophones as pressure variations in the surrounding water. The mechanical energy of these pressure variations is transformed into an electrical signal by ~he hydro-phones and transmitted through the streamer to recording apparatus aboard the vessel. The collected data may then be interpreted by those skilled in the art to reveal information about the subsea geological formations.
For the signals to be meaningful, it is neces-sary to know the placement of the individual hydrophones at the time the pressure waves are detected. As the vessel is continuously movlng and as the streamer may extend for thousands of feet behind the vessel, accurate location of the streamer hydrophones is difficult~
~ arious systems have been developed to provide accurate information as to the location of the vessel. In a common application a plurality of underwater trans-ponders generate unique output frequency signals in ~ 2 01 response to an interrogation signal from the ship. Thetransit time for the interrogation signal and the trans-ponder's response signal is measured and the distance or range from each transponder is calculated. The vessel's 05 position with respect to the transponders may then be triangulated if the location of the transponders are known.
However, it is rare for the streamer to trail directly along the path of the vessel. While the streamer is attached to the stern of the vessel, the bulk of the streamer is submerged below the water surface through the action of depth controllers along the length of the streamer. As a result, the cross-track current velocity at the streamer depth may differ from the cross-track current affecting the vessel, thereby causing the streamer to trail at an angle to the vessel's course. Other factors, which are not necessary to enumerate, may also create a variance in the path of the streamer when compared to the vessel track.
One method of estimating the location of the streamer disclosed in the prior art relies upon the addi-tion of a tail buoy radar reflector located at the end of the streamer. On-board radar systems may then be used under optimal sea conditions to find the end of the streamer and the location of the individual hydrophones interpolated. Such systems are generally unreliable however, and render the required data suspect.
A second method taught by the art relies upon very sensitive and expensive apparatus to measure the yaw and pitch angles of the skreamer end adjacent the vessel.
These data, coupled with magnetic compass headings taken along the streamer and the known depth o~ the streamer, permits one to empirically calculate the hydrophone locations.
It is an object of this invention to provide an accurate, alternative means for locating the submerged streamer which overcomes the c~eEiciencies of the prior art.
SUMMARY OF THE INVENTIO
The present invention provides apparatus for use in 0 1~
determining~/relative to a known geographic location on a sea floor of a submerged marine streamer being towed through the sea by an exploration vessel, which comprises: means for initiating an coustic command signal from the vessel while moving through the sea; at least three transponders spatially located in known positions on the sea floor so as to provide distinct acoustic paths to said vessel and to a streamer towed by said vessel, each of said transponders capable of respond-ing to a single command signal from said vessel by emitting acousti.c signals of a distinctly different frequency from each of other said transponders; a plurality of spaced apart receivers carried by said streamer capable of receiving said different frequencies of acoustic signals emitted by each transponder and indïvidually relaying a distinct signal along 2Q the streamer to the vessel responsIve to each of said received signals; a vessel receiver capable of receiving and distinguish-ing said distinctly different acoustic frequencies emitted from - said transponders; and means for recording the time interval from initiation of a command signal from said vessel to receip.t of each signal relayed from said spaced receivers along said streamer and recording the time interval from initiation of said command signal to receipt of a signal from each of said transponders by said vessel receiver, whereby the distance of each of said streamer receivers from each of said known 3Q positions of said transponders may be calculated.
5~,~æ
-3a-The present invention also provides a method for determining the location of a submerged marine seismic streamer while being towed by an exploration vessel, which comprises:
posit.ioning at least three transponders at known spaced apart locations on a sea floor; towing a marine seismic from an exploration vessel in the sea generally above said trans-ponders; generating an acoustic command signal from said vessel on a periodic basis; receiving said acoustic command signal by said at least three transponders and in response to said acoustic command signal emitting a distinctly different acoustic signal from each of said transducers; detecting each of the transponder acoustic response signals at a plurality of receivers spaced along said streamer; relaying a distinct signal along said streamer in response to each of said detected signals for recording thereof at said vessel and recording each of said transponder acoustic signals at said vessel; and measurin~ the time intervals from generation of said acoustic command signal to receipt of each of said response signals relayed from said spaced receivers along said streamer and the time intervals from generation of said command signal to receipt of each of said transducer signals recorded at said vessel, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
Preferably, the transponders are placed in a non-colinear relationship and each streamer receiver is serviced ~ya separate channel housed in the streamer for relaying signals to the vessel. The receivers may be either active or passive~
but are preferably passive to minimize weight and expense. The apparatus may further comprise means for measuring the vessel's velocity ~lith respect to the array of transponders situated on the ocean æ
01 floor. Said means for measuring the vessel's velocity may include apparatus for measuring the Doppler shift in the frequency of the pulses generated by the transponders.
BRIEF DESCRIPTION OF THE DRAWING~
05 FTG. 1 of the drawings illustrates a transponder array shown in relationship to a surface exploration vessel towing a marine streamer.
FIG. 2 of the drawings diagrammatically illus-trates the effect of shipment movement on the acoustic paths between vessel and transponder.
DET~ILED DESCRIPTION OF T~E PREFERRED EMBODIMENTS
The present invention requires the placement of a plurality of acoustic transponders on, or adjacent, the ocean bottom. Preferably, the transponders will be positioned on the sea floor in non-colinear arrays of at least three transponders per array. Each transponder in a given triplet is preferably placed at a sufficient dis~
tance apart to give adequate range to the ship and streamer receivers in a given water depth. ~hile the present lnvention is concerned wi~h location of the vessel and streamer with respect to a given array and not with respect to the actual geographical location, the latter relationship may be established from knowledge of the transpander placement. Well known methods are described in the art for determination of the transponder placement and calibration and are therefore not to be considered here.
Referring to FIG. l of the drawings, there is sho~m a single array of three acoustic transponders, indicated generally by reference numerals 10, 12 and 14, positioned on the sea floor 16. An exploration vessel 18 is shown on the surface towing a streamer 20.
rrransponders of the type required are commer-cially available and normally comprise a base plate 22, resting on the sea floor, and a cable 24 attached between ~L~95~62 01 the base plate 22 and the transponder body 26. A float 28 connected to the transponder body 26 by means of a cable 30 maintains the transponder body 26 at an attitude above the sea floor determined by the length of cable 24. Float - ~ OS 28 also provides a means of retrieval if cable ~ is severed.
Vessel 18 is equipped with an acoustic trans-ceiver 32 for sending command or interrogation acoustic signals through the water to the transponders and, in turn, receiving responsive signals therefrom. Preferably, all transponders in the array will respond to a single frequency signal emitted by the vessel's transceiver, however, coded signals may be generated to actuate the individual transponders from the vessel, if desired.
The marine streamer 20 is submerged belo~ the water surface by a plurality of conventional depth controllers (not shown) and will normally house hydro-phones (n~t shown), and depth sensors (not shown) which may be interrogated from the vessel for information.
In addition, the streamer will also house a plurality of ~coustic receivers 34 spaced along the length of the streamer. Receivers 34 are capable of de~ecting the signals generated by the transponders and relaying identifiable responses along the streamer to the vessel~
Normally the streamer will have individual channels leading from each receiver to the vessel for transmitting the information. Although the receivers may be active, or powered, it is preferred that the receivers be passive.
To determine the location o~ receivers 34 and thus the streamer position, the vessel 15 acoustic trans-ceiver 32 is triggered to send an acoustic command signal.
Upon receipt of the signal, after the delay in trans-mission time through the water, each transponder transmits an acoustic pulse of a distin~uishable frequency. These pulses are detected by transceiver 32 and by the acoustic 01 receivers 34 housed in the streamer. For`the sake of clarity, acoustic travel paths are only shown in FIG. 1 of the drawing as dashed lines for the vessel transceiver, transponders, and a single receiver in the streamer. It ns should be understood, however, that similar paths could be drawn for each of the receivers housed in the streamer.
Arrows Il, I2 and I3 represent the command pulse travel-; ling alon~ the dashed lines from the ship to the trans-ponders, arrows R1, R2, and R3 represent the responsive pulses from the transponders to the vessel and arrows R'l, R'2 and R'3 indicate the pulse lines of travel to the receiver housed in the streamer. Since the spatial posi-tions of the transponders on the sea floor and the speed o~ sound through the water are known, the receiver posi~
tion may be triangulated from knowledge of the travel time for each pulse from their respective transponders.
Suitable means aboard the vessel are provided to measure the time interval between the sending of th`e com-mand signal and the receipt of the pulses from the trans-ponders and the receivers.
In FIG. 2 of the drawings, there is illustrateda single vessel moving along the water's surface at time To and at a subsequent time Tl. As shown therein, the vessel's transceiver initiates a pulse at time To which travels in a straight line along the indicated path to the transponder. Upon receipt of the signal at time Td the transponder transmits a pulse which is detected by the vessel transceiver at time Tl. From the figure it may be derived that the time, Td~ is given by the formula-Td = To + (Tl - To) (1 v)
BACKGROUND OF THE INVENTION
Field of the Invention os The present invention finds principal applica-tion within the field of marine seismic exploration. More particularly, the invention is concerned with means for accurately determining the position of a towed marine seismic streamer.
Prior Art In marine seismic prospecting, an exploration vessel tows a seismic streamer having a plurality of pressure sensitive detectors, commonly referred to as hydrophones. A source of seismic energy, such as an air gun or an explosive charge, is used to propagate pressure waves through the water into the underlying sea floorO
Part of the energy will be reflected by subfloor geolog~
ical discontinuities and subsequently detected by the hydrophones as pressure variations in the surrounding water. The mechanical energy of these pressure variations is transformed into an electrical signal by ~he hydro-phones and transmitted through the streamer to recording apparatus aboard the vessel. The collected data may then be interpreted by those skilled in the art to reveal information about the subsea geological formations.
For the signals to be meaningful, it is neces-sary to know the placement of the individual hydrophones at the time the pressure waves are detected. As the vessel is continuously movlng and as the streamer may extend for thousands of feet behind the vessel, accurate location of the streamer hydrophones is difficult~
~ arious systems have been developed to provide accurate information as to the location of the vessel. In a common application a plurality of underwater trans-ponders generate unique output frequency signals in ~ 2 01 response to an interrogation signal from the ship. Thetransit time for the interrogation signal and the trans-ponder's response signal is measured and the distance or range from each transponder is calculated. The vessel's 05 position with respect to the transponders may then be triangulated if the location of the transponders are known.
However, it is rare for the streamer to trail directly along the path of the vessel. While the streamer is attached to the stern of the vessel, the bulk of the streamer is submerged below the water surface through the action of depth controllers along the length of the streamer. As a result, the cross-track current velocity at the streamer depth may differ from the cross-track current affecting the vessel, thereby causing the streamer to trail at an angle to the vessel's course. Other factors, which are not necessary to enumerate, may also create a variance in the path of the streamer when compared to the vessel track.
One method of estimating the location of the streamer disclosed in the prior art relies upon the addi-tion of a tail buoy radar reflector located at the end of the streamer. On-board radar systems may then be used under optimal sea conditions to find the end of the streamer and the location of the individual hydrophones interpolated. Such systems are generally unreliable however, and render the required data suspect.
A second method taught by the art relies upon very sensitive and expensive apparatus to measure the yaw and pitch angles of the skreamer end adjacent the vessel.
These data, coupled with magnetic compass headings taken along the streamer and the known depth o~ the streamer, permits one to empirically calculate the hydrophone locations.
It is an object of this invention to provide an accurate, alternative means for locating the submerged streamer which overcomes the c~eEiciencies of the prior art.
SUMMARY OF THE INVENTIO
The present invention provides apparatus for use in 0 1~
determining~/relative to a known geographic location on a sea floor of a submerged marine streamer being towed through the sea by an exploration vessel, which comprises: means for initiating an coustic command signal from the vessel while moving through the sea; at least three transponders spatially located in known positions on the sea floor so as to provide distinct acoustic paths to said vessel and to a streamer towed by said vessel, each of said transponders capable of respond-ing to a single command signal from said vessel by emitting acousti.c signals of a distinctly different frequency from each of other said transponders; a plurality of spaced apart receivers carried by said streamer capable of receiving said different frequencies of acoustic signals emitted by each transponder and indïvidually relaying a distinct signal along 2Q the streamer to the vessel responsIve to each of said received signals; a vessel receiver capable of receiving and distinguish-ing said distinctly different acoustic frequencies emitted from - said transponders; and means for recording the time interval from initiation of a command signal from said vessel to receip.t of each signal relayed from said spaced receivers along said streamer and recording the time interval from initiation of said command signal to receipt of a signal from each of said transponders by said vessel receiver, whereby the distance of each of said streamer receivers from each of said known 3Q positions of said transponders may be calculated.
5~,~æ
-3a-The present invention also provides a method for determining the location of a submerged marine seismic streamer while being towed by an exploration vessel, which comprises:
posit.ioning at least three transponders at known spaced apart locations on a sea floor; towing a marine seismic from an exploration vessel in the sea generally above said trans-ponders; generating an acoustic command signal from said vessel on a periodic basis; receiving said acoustic command signal by said at least three transponders and in response to said acoustic command signal emitting a distinctly different acoustic signal from each of said transducers; detecting each of the transponder acoustic response signals at a plurality of receivers spaced along said streamer; relaying a distinct signal along said streamer in response to each of said detected signals for recording thereof at said vessel and recording each of said transponder acoustic signals at said vessel; and measurin~ the time intervals from generation of said acoustic command signal to receipt of each of said response signals relayed from said spaced receivers along said streamer and the time intervals from generation of said command signal to receipt of each of said transducer signals recorded at said vessel, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
Preferably, the transponders are placed in a non-colinear relationship and each streamer receiver is serviced ~ya separate channel housed in the streamer for relaying signals to the vessel. The receivers may be either active or passive~
but are preferably passive to minimize weight and expense. The apparatus may further comprise means for measuring the vessel's velocity ~lith respect to the array of transponders situated on the ocean æ
01 floor. Said means for measuring the vessel's velocity may include apparatus for measuring the Doppler shift in the frequency of the pulses generated by the transponders.
BRIEF DESCRIPTION OF THE DRAWING~
05 FTG. 1 of the drawings illustrates a transponder array shown in relationship to a surface exploration vessel towing a marine streamer.
FIG. 2 of the drawings diagrammatically illus-trates the effect of shipment movement on the acoustic paths between vessel and transponder.
DET~ILED DESCRIPTION OF T~E PREFERRED EMBODIMENTS
The present invention requires the placement of a plurality of acoustic transponders on, or adjacent, the ocean bottom. Preferably, the transponders will be positioned on the sea floor in non-colinear arrays of at least three transponders per array. Each transponder in a given triplet is preferably placed at a sufficient dis~
tance apart to give adequate range to the ship and streamer receivers in a given water depth. ~hile the present lnvention is concerned wi~h location of the vessel and streamer with respect to a given array and not with respect to the actual geographical location, the latter relationship may be established from knowledge of the transpander placement. Well known methods are described in the art for determination of the transponder placement and calibration and are therefore not to be considered here.
Referring to FIG. l of the drawings, there is sho~m a single array of three acoustic transponders, indicated generally by reference numerals 10, 12 and 14, positioned on the sea floor 16. An exploration vessel 18 is shown on the surface towing a streamer 20.
rrransponders of the type required are commer-cially available and normally comprise a base plate 22, resting on the sea floor, and a cable 24 attached between ~L~95~62 01 the base plate 22 and the transponder body 26. A float 28 connected to the transponder body 26 by means of a cable 30 maintains the transponder body 26 at an attitude above the sea floor determined by the length of cable 24. Float - ~ OS 28 also provides a means of retrieval if cable ~ is severed.
Vessel 18 is equipped with an acoustic trans-ceiver 32 for sending command or interrogation acoustic signals through the water to the transponders and, in turn, receiving responsive signals therefrom. Preferably, all transponders in the array will respond to a single frequency signal emitted by the vessel's transceiver, however, coded signals may be generated to actuate the individual transponders from the vessel, if desired.
The marine streamer 20 is submerged belo~ the water surface by a plurality of conventional depth controllers (not shown) and will normally house hydro-phones (n~t shown), and depth sensors (not shown) which may be interrogated from the vessel for information.
In addition, the streamer will also house a plurality of ~coustic receivers 34 spaced along the length of the streamer. Receivers 34 are capable of de~ecting the signals generated by the transponders and relaying identifiable responses along the streamer to the vessel~
Normally the streamer will have individual channels leading from each receiver to the vessel for transmitting the information. Although the receivers may be active, or powered, it is preferred that the receivers be passive.
To determine the location o~ receivers 34 and thus the streamer position, the vessel 15 acoustic trans-ceiver 32 is triggered to send an acoustic command signal.
Upon receipt of the signal, after the delay in trans-mission time through the water, each transponder transmits an acoustic pulse of a distin~uishable frequency. These pulses are detected by transceiver 32 and by the acoustic 01 receivers 34 housed in the streamer. For`the sake of clarity, acoustic travel paths are only shown in FIG. 1 of the drawing as dashed lines for the vessel transceiver, transponders, and a single receiver in the streamer. It ns should be understood, however, that similar paths could be drawn for each of the receivers housed in the streamer.
Arrows Il, I2 and I3 represent the command pulse travel-; ling alon~ the dashed lines from the ship to the trans-ponders, arrows R1, R2, and R3 represent the responsive pulses from the transponders to the vessel and arrows R'l, R'2 and R'3 indicate the pulse lines of travel to the receiver housed in the streamer. Since the spatial posi-tions of the transponders on the sea floor and the speed o~ sound through the water are known, the receiver posi~
tion may be triangulated from knowledge of the travel time for each pulse from their respective transponders.
Suitable means aboard the vessel are provided to measure the time interval between the sending of th`e com-mand signal and the receipt of the pulses from the trans-ponders and the receivers.
In FIG. 2 of the drawings, there is illustrateda single vessel moving along the water's surface at time To and at a subsequent time Tl. As shown therein, the vessel's transceiver initiates a pulse at time To which travels in a straight line along the indicated path to the transponder. Upon receipt of the signal at time Td the transponder transmits a pulse which is detected by the vessel transceiver at time Tl. From the figure it may be derived that the time, Td~ is given by the formula-Td = To + (Tl - To) (1 v)
2 c 01 wherein v is the vessel's velocity with rèspect to the transponder and c is the propagation speed of the acoustic pulses.
The v ratio may be determined in a number of 05 c ways. A preferred method, however, relies upon the measurement of the Doppler shift in the received frequency from the transponder. Naturally, in order to determine the velocity in this manner, the transponders must be capable of generating pulses of very stable frequencies and the vessel receiver must be capable of measuring the apparent change in the frequency.
The ratio may also be calculated from the rate of change of range in the direction of the transponders lS and the vessel. This range rate may be determined readily from knowledge of the vessel's position and speed with respect to the transponders.
The ratio v for normal ship speeds during seismic operations will usually be less -than .002, since v is about 3 meters per second and c is about 1,500 meters per second. If the v term is dropped then:
c Td = To + (Tl To) with an error of less 0.2%. An error of this magnitude may be acceptable for the ocean depths encountered in oil industry for some types of seismic operations.
Knowledge of the time, Td, for the initiation of the pulses from the transponders and the measured time of pulse detection by the receivers in the streamer as trans-mitted to the vessel permits the calculation of the dis-tance from each transponder to each receiver. These dis-tances may then be triangulated to give the location of ~s~7~æ
01 each receiver in a streamer in real time by a shipboard computer or from the recorded data in post missionanalysis.
The v ratio may be determined in a number of 05 c ways. A preferred method, however, relies upon the measurement of the Doppler shift in the received frequency from the transponder. Naturally, in order to determine the velocity in this manner, the transponders must be capable of generating pulses of very stable frequencies and the vessel receiver must be capable of measuring the apparent change in the frequency.
The ratio may also be calculated from the rate of change of range in the direction of the transponders lS and the vessel. This range rate may be determined readily from knowledge of the vessel's position and speed with respect to the transponders.
The ratio v for normal ship speeds during seismic operations will usually be less -than .002, since v is about 3 meters per second and c is about 1,500 meters per second. If the v term is dropped then:
c Td = To + (Tl To) with an error of less 0.2%. An error of this magnitude may be acceptable for the ocean depths encountered in oil industry for some types of seismic operations.
Knowledge of the time, Td, for the initiation of the pulses from the transponders and the measured time of pulse detection by the receivers in the streamer as trans-mitted to the vessel permits the calculation of the dis-tance from each transponder to each receiver. These dis-tances may then be triangulated to give the location of ~s~7~æ
01 each receiver in a streamer in real time by a shipboard computer or from the recorded data in post missionanalysis.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for use in determining the location relative to a known geographic location on a sea floor of a submerged marine streamer being towed through the sea by an exploration vessel, which comprises:
means for initiating an acoustic command signal from the vessel while moving through the sea; at least three trans-ponders spatially located in known positions on the sea floor so as to provide distinct acoustic paths to said vessel and to a streamer towed by said vessel, each of said trans-ponders capable of responding to a single command signal from said vessel by emitting acoustic signals of a distinctly different frequency from each of other said transponders;
a plurality of spaced apart receivers carried by said streamer capable of receiving said different frequencies of acoustic signals emitted by each transponder and individually relaying a distinct signal along the streamer to the vessel responsive to each of said received signals; a vessel receiver capable of receiving and distinguishing said distinctly different acoustic frequencies emitted from said transponders; and means for recording the time interval from initiation of a command signal from said vessel to receipt of each signal relayed from said spaced receivers along said streamer and recording the time interval from initiation of said command signal to receipt of a signal from each of said transponders by said vessel receiver, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
means for initiating an acoustic command signal from the vessel while moving through the sea; at least three trans-ponders spatially located in known positions on the sea floor so as to provide distinct acoustic paths to said vessel and to a streamer towed by said vessel, each of said trans-ponders capable of responding to a single command signal from said vessel by emitting acoustic signals of a distinctly different frequency from each of other said transponders;
a plurality of spaced apart receivers carried by said streamer capable of receiving said different frequencies of acoustic signals emitted by each transponder and individually relaying a distinct signal along the streamer to the vessel responsive to each of said received signals; a vessel receiver capable of receiving and distinguishing said distinctly different acoustic frequencies emitted from said transponders; and means for recording the time interval from initiation of a command signal from said vessel to receipt of each signal relayed from said spaced receivers along said streamer and recording the time interval from initiation of said command signal to receipt of a signal from each of said transponders by said vessel receiver, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
2. Apparatus for use in determining the location of a marine streamer as recited to Claim 1, wherein said transponders are in a non-colinear relationship.
3. Apparatus for use in determining the location of a marine streamer as recited in Claim 1, wherein each of said streamer receivers is passive.
4. Apparatus for use in determining the location of a marine streamer as recited in Claim 1, wherein each streamer receiver is serviced by a separate transmission channel in said streamer for relaying transducer signals to the vessel.
5. Apparatus for use in determining the location of a marine streamer as recited in Claim 1, further comprising:
means for measuring the vessels rate of change in velocity with respect to each of said transponders.
means for measuring the vessels rate of change in velocity with respect to each of said transponders.
6. Apparatus for use in determining the location of a marine streamer as recited in Claim 5, wherein said means for measuring the vessel's velocity includes means for measuring the Doppler shift in the frequency of the received acoustic signal generated by each of said transponders and the known frequency of each of said acoustic signals transmitted by said transducers.
7. A method for determining the location of a submerged marine seismic streamer while being towed by an exploration vessel, which comprises:
positioning at least three transponders at known spaced apart locations on a sea floor;
towing a marine seismic from an exploration vessel in the sea generally above said transponders;
generating an acoustic command signal from said vessel on a periodic basis;
receiving said acoustic command signal by said at least three transponders and in response to said acoustic command signal emitting a distinctly different acoustic signal from each of said transducers;
detecting each of the transponder acoustic response signals at a plurality of receivers spaced along said streamer;
relaying a distinct signal along said streamer in response to each of said detected signals for recording thereof at said vessel and recording each of said transponder acoustic signals at said vessel; and measuring the time intervals from generation of said acoustic command signal to receipt of each of said response signals relayed from said spaced receivers along said streamer and the time intervals from generation of said command signal to receipt of each of said transducer signals recorded at said vessel, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
positioning at least three transponders at known spaced apart locations on a sea floor;
towing a marine seismic from an exploration vessel in the sea generally above said transponders;
generating an acoustic command signal from said vessel on a periodic basis;
receiving said acoustic command signal by said at least three transponders and in response to said acoustic command signal emitting a distinctly different acoustic signal from each of said transducers;
detecting each of the transponder acoustic response signals at a plurality of receivers spaced along said streamer;
relaying a distinct signal along said streamer in response to each of said detected signals for recording thereof at said vessel and recording each of said transponder acoustic signals at said vessel; and measuring the time intervals from generation of said acoustic command signal to receipt of each of said response signals relayed from said spaced receivers along said streamer and the time intervals from generation of said command signal to receipt of each of said transducer signals recorded at said vessel, whereby the distance of each of said streamer receivers from each of said known positions of said transponders may be calculated.
8. A method as recited in Claim 7, further comprising:
measuring the Doppler shifts in the known frequency of each of said signals emitted by one of said transponders and the frequency of the corresponding acoustic signal detected at said vessel.
measuring the Doppler shifts in the known frequency of each of said signals emitted by one of said transponders and the frequency of the corresponding acoustic signal detected at said vessel.
9. A method as recited in Claim 7, further comprising:
measuring the average rate of change in range of said vessel with respect to each of said transponders from changes in the measured time for signal travel from each of said transponders to said vessel in response to said acoustic command signal during a plurality of successive generations of said acoustic command signals.
measuring the average rate of change in range of said vessel with respect to each of said transponders from changes in the measured time for signal travel from each of said transponders to said vessel in response to said acoustic command signal during a plurality of successive generations of said acoustic command signals.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21519580A | 1980-12-10 | 1980-12-10 | |
| US215,195 | 1980-12-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1195762A true CA1195762A (en) | 1985-10-22 |
Family
ID=22802047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000391897A Expired CA1195762A (en) | 1980-12-10 | 1981-12-09 | Submerged marine streamer locator |
Country Status (15)
| Country | Link |
|---|---|
| JP (2) | JPS57141571A (en) |
| AU (1) | AU545131B2 (en) |
| BR (1) | BR8107971A (en) |
| CA (1) | CA1195762A (en) |
| DE (1) | DE3149162A1 (en) |
| DK (1) | DK161266C (en) |
| ES (1) | ES8301032A1 (en) |
| FR (1) | FR2495783B1 (en) |
| GB (1) | GB2089043B (en) |
| IT (1) | IT1139931B (en) |
| NL (1) | NL8105493A (en) |
| NO (1) | NO156627C (en) |
| NZ (1) | NZ199066A (en) |
| YU (1) | YU42748B (en) |
| ZA (1) | ZA818225B (en) |
Families Citing this family (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2530823B1 (en) * | 1982-07-21 | 1985-12-06 | Sintra Alcatel Sa | ACOUSTIC ECARTOMETRY MEASURING DEVICE AND METHOD FOR ITS IMPLEMENTATION |
| US4532617A (en) * | 1982-09-29 | 1985-07-30 | Baecker Donald Ray | System for locating a towed marine object |
| NO161090C (en) * | 1983-04-29 | 1989-06-28 | Norske Stats Oljeselskap | PROCEDURE FOR POSITION DETERMINATION OF MARINE SEISMIC RECEIVER CABLE. |
| US4641287A (en) * | 1984-04-30 | 1987-02-03 | Mobil Oil Corporation | Method for locating an on-bottom seismic cable |
| JPS61228371A (en) * | 1985-04-01 | 1986-10-11 | Unyusho Daiyon Kowan Kensetsu Kyokucho | Apparatus for detecting position in water |
| USH549H (en) * | 1985-04-22 | 1988-12-06 | Shell Oil Company | Apparatus and method for locating towed seismic apparatus |
| GB8531952D0 (en) * | 1985-12-31 | 1986-02-05 | Sar Plc | Stereo balance adjuster |
| FR2601143B1 (en) * | 1986-07-01 | 1988-12-02 | Geophysique Cie Gle | METHOD AND SYSTEM FOR LOCATING AND CORRECTING ORIENTATION OF A SELF-CONTAINED MOBILE OBJECT AND OF A NON-SELF-CONTAINED MOBILE OBJECT |
| GB2209602A (en) * | 1987-09-09 | 1989-05-17 | Michael Owen | Phased arrays of ultrasonic emitters used with a mobile receiver |
| FR2643463B1 (en) * | 1989-02-17 | 1991-09-27 | Software Based Systems | METHOD AND DEVICE FOR POSITIONING AN UNDERWATER OBJECT IN RELATION TO AN ABSOLUTE REFERENTIAL, AND USING A SURFACE RELAY REFERENTIAL |
| DE9108370U1 (en) * | 1991-07-02 | 1992-11-05 | Stiftung Alfred-Wegener-Institut Fuer Polar- Und Meeresforschung, 2850 Bremerhaven, De | |
| EP1379895B1 (en) | 2001-03-22 | 2017-03-22 | Nautronix (Holdings) Limited | Improved underwater station |
| AU2002238304B2 (en) * | 2001-03-22 | 2004-11-11 | Nautronix (Holdings) Plc | Improved underwater station |
| AU2002238303B2 (en) * | 2001-03-22 | 2004-11-11 | Nautronix (Holdings) Plc | Positioning system |
| JP2003019999A (en) * | 2001-07-09 | 2003-01-21 | Mitsui Eng & Shipbuild Co Ltd | Sea bottom stratum exploration system |
| GB2394045B (en) * | 2002-10-11 | 2006-07-26 | Westerngeco Seismic Holdings | Method and apparatus for positioning of seismic sensing cables |
| GB2409900B (en) | 2004-01-09 | 2006-05-24 | Statoil Asa | Processing seismic data representing a physical system |
| GB2435693A (en) | 2006-02-09 | 2007-09-05 | Electromagnetic Geoservices As | Seabed electromagnetic surveying |
| GB2439378B (en) | 2006-06-09 | 2011-03-16 | Electromagnetic Geoservices As | Instrument for measuring electromagnetic signals |
| GB2442749B (en) | 2006-10-12 | 2010-05-19 | Electromagnetic Geoservices As | Positioning system |
| GB2445582A (en) | 2007-01-09 | 2008-07-16 | Statoil Asa | Method for analysing data from an electromagnetic survey |
| CN102854217B (en) * | 2012-09-11 | 2014-07-16 | 西安近代化学研究所 | Assembling and disassembling device of calorimetric cover used in explosion heat measurement |
| US20190339414A1 (en) * | 2017-02-15 | 2019-11-07 | Halliburton Energy Services, Inc. | Evaluating subsea geodetic data |
| CN106990431B (en) * | 2017-05-18 | 2023-08-15 | 国家海洋局第一海洋研究所 | Offshore bottom hydrate detection system |
| CN112433218B (en) * | 2020-11-17 | 2024-02-13 | 海鹰企业集团有限责任公司 | Method for realizing ship conformal array virtual baffle |
| DE102022205472A1 (en) | 2022-05-31 | 2023-11-30 | Atlas Elektronik Gmbh | Hydroacoustic sound transmitter array |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2123049B1 (en) * | 1970-08-07 | 1974-02-01 | Electronique Appliquee | |
| US3860900A (en) * | 1973-02-21 | 1975-01-14 | Western Electric Co | Method of monitoring the position of towed underwater apparatus |
| FR2218571B1 (en) * | 1973-02-21 | 1976-05-14 | Erap | |
| JPS5646110B2 (en) * | 1973-07-07 | 1981-10-30 | ||
| US4037189A (en) * | 1975-10-20 | 1977-07-19 | Western Gear Corporation | Method and apparatus for determining the profile of an underwater pipeline |
| JPS52140357A (en) * | 1976-05-15 | 1977-11-22 | Sanders Associates Inc | Selffdriven array system |
| NO147618L (en) * | 1976-11-18 | |||
| DE2750942A1 (en) * | 1977-11-15 | 1979-05-17 | Texaco Development Corp | Offshore marine seismic source tow system - maintain a predetermined distance between a paravane and a geophone streamer cable |
| US4229809A (en) * | 1979-01-29 | 1980-10-21 | Sperry Corporation | Acoustic under sea position measurement system |
-
1981
- 1981-11-25 NZ NZ199066A patent/NZ199066A/en unknown
- 1981-11-26 ZA ZA818225A patent/ZA818225B/en unknown
- 1981-12-02 FR FR8122573A patent/FR2495783B1/en not_active Expired
- 1981-12-04 IT IT25479/81A patent/IT1139931B/en active
- 1981-12-07 NL NL8105493A patent/NL8105493A/en not_active Application Discontinuation
- 1981-12-08 DE DE19813149162 patent/DE3149162A1/en active Granted
- 1981-12-08 BR BR8107971A patent/BR8107971A/en unknown
- 1981-12-08 GB GB8136899A patent/GB2089043B/en not_active Expired
- 1981-12-09 AU AU78415/81A patent/AU545131B2/en not_active Ceased
- 1981-12-09 CA CA000391897A patent/CA1195762A/en not_active Expired
- 1981-12-09 DK DK545781A patent/DK161266C/en not_active IP Right Cessation
- 1981-12-09 YU YU2893/81A patent/YU42748B/en unknown
- 1981-12-09 NO NO814197A patent/NO156627C/en unknown
- 1981-12-10 ES ES507851A patent/ES8301032A1/en not_active Expired
- 1981-12-10 JP JP56199459A patent/JPS57141571A/en active Pending
-
1990
- 1990-01-22 JP JP1990004561U patent/JPH0339742Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| AU545131B2 (en) | 1985-07-04 |
| DK161266C (en) | 1991-12-02 |
| DE3149162C2 (en) | 1990-02-15 |
| GB2089043A (en) | 1982-06-16 |
| ES507851A0 (en) | 1982-11-01 |
| FR2495783A1 (en) | 1982-06-11 |
| NZ199066A (en) | 1985-08-30 |
| NO156627C (en) | 1987-10-21 |
| JPH0339742Y2 (en) | 1991-08-21 |
| JPH02105176U (en) | 1990-08-21 |
| YU289381A (en) | 1983-12-31 |
| DK161266B (en) | 1991-06-17 |
| IT1139931B (en) | 1986-09-24 |
| FR2495783B1 (en) | 1986-05-23 |
| NO156627B (en) | 1987-07-13 |
| ZA818225B (en) | 1982-10-27 |
| NL8105493A (en) | 1982-07-01 |
| NO814197L (en) | 1982-06-11 |
| AU7841581A (en) | 1982-09-23 |
| YU42748B (en) | 1988-12-31 |
| IT8125479A0 (en) | 1981-12-04 |
| DK545781A (en) | 1982-06-11 |
| BR8107971A (en) | 1982-09-14 |
| GB2089043B (en) | 1984-05-31 |
| JPS57141571A (en) | 1982-09-01 |
| DE3149162A1 (en) | 1982-08-12 |
| ES8301032A1 (en) | 1982-11-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1195762A (en) | Submerged marine streamer locator | |
| US4635236A (en) | Submerged marine streamer locator | |
| US4669067A (en) | Method and apparatus for locating a submerged marine streamer | |
| US4532617A (en) | System for locating a towed marine object | |
| US4376301A (en) | Seismic streamer locator | |
| EP0680615B1 (en) | Methods for determining the position of seismic equipment, and applications of the methods | |
| US7660189B2 (en) | Apparatus, systems and methods for determining position of marine seismic acoustic receivers | |
| US4555779A (en) | Submerged marine streamer locator | |
| US5128904A (en) | Method for estimating the location of a sensor relative to a seismic energy source | |
| US4446538A (en) | Marine cable location system | |
| US3906352A (en) | Method of making a three-dimensional seismic profile of ocean floor | |
| CA1240782A (en) | Method for locating an on-bottom seismic cable | |
| JPS60500383A (en) | Device in hydrophone cable for marine seismic exploration | |
| US4513401A (en) | Marine cable location system | |
| US4709356A (en) | Seismic array positioning | |
| Boegeman et al. | Precise positioning for near-bottom equipment using a relay transponder | |
| US20100102985A1 (en) | Receiver orientation in an electromagnetic survey | |
| USH549H (en) | Apparatus and method for locating towed seismic apparatus | |
| US20130077435A1 (en) | Methods and apparatus for streamer positioning during marine seismic exploration | |
| CN101469982A (en) | Depth measurement for sound impulse emitter by utilization of seismic spread | |
| AU688825C (en) | Methods for determining the position of seismic equipment, and applications of the methods | |
| Court | Applications of acoustics to streamer/source positioning |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |