Exhibit A
`
`Exhibit A
`(PGS 1002)
`(PGS 1002)
`
`
`
`
`
`
`
`

`
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`PETROLEUM GEO-SERVICES INC.
`Petitioner
`v.
`
`WESTERNGECO LLC
`Patent Owner
`
`
`
`CASE IPR: Unassigned
`Patent 7,080,607 B2
`
`
`DECLARATION OF DR. BRIAN J. EVANS, PhD.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`

`
`
`
`INTRODUCTION ............................................................................................... 2
`I.
`QUALIFICATIONS ........................................................................................ 3
`II.
`III. COMPENSATION AND RELATIONSHIP TO THE PARTIES .................. 8
`IV. LEGAL STANDARDS ................................................................................... 9
`A.
`Claim Construction ...................................................................................... 9
`B.
`Anticipation .................................................................................................. 9
`C.
`Obviousness ............................................................................................... 10
`D.
`Person of Ordinary Skill in the Art ............................................................ 10
`V.
`SUMMARY OF OPINION ........................................................................... 11
`VI. TECHNICAL BACKGROUND ................................................................... 12
`B.
`Streamer Steering Overview ...................................................................... 20
`C.
`The Workman Patent .................................................................................. 44
`VII. THE ’607 PATENT ....................................................................................... 46
`A.
`Brief Description of the Relevant File History .......................................... 46
`B.
`Relevant Time Frame for Analysis of the ’607 Patent .............................. 48
`C.
`The Specification of the ’607 Patent .......................................................... 48
`VIII. DETAILED OPINION ............................................................................... 50
`A.
`The Challenged Claims – Claims 1 and 15 of the ’607 Patent .................. 50
`B.
`Construction of Relevant Claim Terms ..................................................... 51
`C.
`Admitted Prior Art in the ’607 Patent ........................................................ 57
`D.
`Claims 1 and 15 are Anticipated by Workman .......................................... 59
`E.
` Claims 1 and 15 are Obvious over Workman ............................................ 74
`F.
` Claims 1 and 15 are Obvious over Workman in view of Elholm .............. 77
`G.
`Claims 1 and 15 are Obvious over Gikas in view of the ’636 PCT ........... 81
`H.
`Claims 1 and 15 are Obvious over Gikas in view of Elholm .................... 94
`
`
`
`
`
`1
`
`

`
`
`
`I, Dr. Brian Evans, hereby state the following:
`
`
`I. INTRODUCTION
`1.
`I have been retained by Petroleum Geo-Services, Inc. (“PGS”) to
`
`provide technical assistance related to the filing of a Petition for Inter Partes
`
`Review of U.S. Patent No. 7,080,607 B2 (“the ’607 Patent”) (Ex. 1001). I am
`
`working as a private consultant on this matter and the opinions presented here are
`
`my own.
`
`2.
`
`I have been asked to prepare a written report, including comments
`
`related to whether Claims 1 and 15 of the ’607 Patent are unpatentable because
`
`they are anticipated or would have been obvious to one of ordinary skill in view of
`
`the prior art. I have reviewed the documents set forth in the attached Appendix of
`
`Exhibits below and relied on my decades of knowledge and experience in the field
`
`of seismic marine surveys (detailed in Section II) in reaching my opinions
`
`regarding validity. This report sets forth the bases and reasons for my opinions,
`
`including the materials and information relied upon in forming those opinions and
`
`conclusions.
`
`3.
`
`This report is based on information currently available to me. I reserve
`
`the right to continue my investigation and analysis, which may include a review of
`
`documents and information not yet produced. I further reserve the right to expand
`
`or otherwise modify my opinions and conclusions as my investigation and study
`
`
`
`2
`
`

`
`
`
`continues, and to supplement my opinions and conclusions in response to any
`
`additional information that becomes available to me.
`
`II. QUALIFICATIONS
`4.
`I am a Professor of Geophysics in the Department of Petroleum
`
`Engineering at Curtin University located in Bentley, Western Australia. I have
`
`worked continuously in the field of marine seismic surveying for over 44 years,
`
`since the 1970s. I have been involved in the design of dozens of marine seismic
`
`surveys, and have been onboard seismic vessels as they were conducting a marine
`
`seismic survey over one-hundred times.
`
`5.
`
`I authored a textbook devoted to marine seismic surveying and data
`
`acquisition, entitled “A Handbook for Seismic Data Acquisition in Exploration.” I
`
`began writing the textbook in 1985 for use in my “Seismic Acquisition” class, and
`
`continued to update it over the years. It was first published in 1997 by the Society
`
`of Exploration Geophysicists (SEG), the premier international organization for
`
`seismic professionals and researchers, including marine seismic professionals. At
`
`the time of its publication, it was considered the authoritative textbook in the field
`
`of seismic data acquisition. Over the past 15 years, it has been used throughout the
`
`world in seismic surveying courses and on seismic survey vessels.
`
`6.
`
`I obtained my Diploma of Electrical Engineering, the equivalent of a
`
`bachelor’s degree, at the J.M. University of Liverpool in the United Kingdom in
`
`
`
`3
`
`

`
`
`
`1969. I took my first job in the marine seismic industry in 1971, working as an
`
`instrument engineer for Geophysical Service, Inc. In that role, I monitored and
`
`repaired the seismic recording and navigation instruments, including the equipment
`
`that positioned marine seismic streamers and source arrays. As a qualified
`
`electrical engineer, I also repaired electronic equipment on seismic vessels,
`
`including on-board computers, and navigation/positioning systems. While with
`
`Geophysical Services, Inc., I traveled the world working offshore West Africa,
`
`South America, India, Vietnam, the Persian Gulf, Indonesia, the Philippines, the
`
`South China Sea, and the Gulf of Thailand—all offshore oil exploration areas.
`
`7.
`
`After leaving Geophysical Service, Inc. in 1974, I joined Aquatronics,
`
`a London-based seismic company, where I managed seismic survey ships used in
`
`seismic surveys. In 1975, I joined Southern Geophysical Consultants of London as
`
`a Seismic Acquisition and Surveying Consultant. In that capacity, I represented
`
`many oil companies while onboard seismic survey ships to ensure the quality of
`
`the acquired seismic data and that the seismic data was within the oil company’s
`
`specifications. I was also involved in deep water operations and rig relocations for
`
`different oil companies during my time at Aquatronics.
`
`8.
`
`In 1976, I established my own seismic-acquisition consulting
`
`company in Perth, Australia, called “Offshore-Onshore Exploration Consultants
`
`PTY LTD.” As an independent consultant, I participated in seismic surveys on
`
`
`
`4
`
`

`
`
`
`behalf of my oil company clients to ensure the quality of the seismic data acquired
`
`and that the seismic data was within the oil company’s specifications. My
`
`consulting company, which employed four other employees, was the only
`
`company that did this type of work in Southeast Asia at the time. From 1980 to
`
`1983, while at the peak of my consultancy operations, I also worked at Shell
`
`Development Australia in Perth, Australia, as a Senior Operations Geophysicist.
`
`My responsibilities at Shell Development included managing three marine-
`
`seismic-survey ships and two land-seismic-survey crews.
`
`9.
`
`In 1983, I enrolled at Curtin University (known then as West
`
`Australian Institute of Technology). From 1983 to 1985, as part of a Masters
`
`program in Applied Physics, I wrote a thesis entitled “The Establishment of a
`
`Digital Seismic Acquisition System and its Subsequent Application in the Field.” I
`
`also designed and built a seismic recording system.
`
`10. After receiving my Masters in Applied Physics in 1985, I enrolled in a
`
`Geophysics Ph.D. program at Curtin University, focusing on 3D Seismic
`
`Surveying Data Processing. As part of the Ph.D program, I taught seismic
`
`acquisition, processing, and interpretation and lectured short-courses for industry
`
`(including marine seismic companies) on conventional and 3D seismic acquisition
`
`methods. While working on my Ph.D, I continued to consult on marine seismic
`
`data acquisition. I also established the Department of Exploration Geophysics at
`
`
`
`5
`
`

`
`
`
`Curtin University. In 1997, I completed my Ph.D. program, and produced a Ph.D
`
`thesis titled, “Advancements in the Techniques of Low-fold Three Dimensional
`
`Seismic Reflection Surveying.”
`
`11. After completing my Ph.D. in Geophysics in 1997, I continued to
`
`teach seismic data acquisition, processing, and interpretation as an Associate
`
`Professor at Curtin University. I also continued to teach short-courses to the
`
`industry on marine seismic data acquisition. Over the years, I have supervised
`
`twenty Master’s and Ph.D. students, many of whom have written theses pertinent
`
`to the marine seismic industry. I continue to supervise four Ph.D. students today.
`
`12.
`
`I became a tenured Professor of Geophysics in 2002. I served as
`
`Chair of the Department of Petroleum Engineering from 2007 to 2012. I then
`
`became the Director of Curtin University’s Faculty of Science and Engineering’s
`
`Oil and Gas Training and Research Project Initiatives in 2013. In that role, I
`
`establish research projects with industry, establish teams to run projects, and
`
`consult with industry and the research staff to ensure the projects stay on track.
`
`13. Much of my research over the years has involved numerical and
`
`physical modeling of the seismic data acquisition process, including in the context
`
`of 3D and 4D seismic marine surveys. This has entailed both field and laboratory
`
`research, in which I would frequently work onboard seismic survey ships during
`
`marine seismic surveys; and later attempt to improve on marine seismic data
`
`
`
`6
`
`

`
`
`
`acquisition techniques by testing in the laboratory. Building on my research to
`
`optimize 3D and 4D data acquisition, I have built three seismic physical
`
`acquisition simulation labs in Houston, Dhahran, and Rio de Janeiro. These labs
`
`involved the use of physical models to simulate 3D marine seismic surveys. The
`
`Houston lab was built in 1991 and later moved and reconstructed at Curtin
`
`University; the other labs were built in 2005 and are presently operated in Dhahran
`
`and Rio de Janeiro. All of these labs are still in use today. I have also developed a
`
`seismic numerical modeling lab at Curtin University, and a landmark seismic
`
`interpretation lab, which oil companies use to train their employees and to interpret
`
`3D marine seismic data.
`
`14. Throughout the 1990s and 2000s, I have continued to consult in the
`
`marine seismic survey field while working at Curtin University. I have consulted
`
`with various marine seismic survey companies as part of my job representing oil
`
`companies and in my independent consulting company. In this role, I am typically
`
`asked to evaluate seismic survey plans and to advise companies on their plans’
`
`suitability for an optimal survey. This often requires me to determine whether the
`
`seismic data acquisition and processing plans are adequate to produce quality
`
`seismic data considering the survey area’s 3D geology. To fulfill this role, I
`
`closely follow the literature and other available information regarding the latest
`
`marine seismic acquisition technologies. I continue to do this consulting work to
`
`
`
`7
`
`

`
`
`
`this day. I have also consulted on a wide range of other issues relating to marine
`
`seismic data acquisition, processing, and interpretation. For instance, I have had
`
`an Independent Advisory Group since 2004 to review and evaluate oil companies’
`
`seismic data, drilling plans and proposed operations.
`
`15.
`
`I am currently a member of several professional organizations related
`
`to the marine seismic industry, and the oil and gas industry in general. I have been
`
`a member of the Australian Society of Exploration Geophysics since 1983 and the
`
`Society of Exploration Geophysicists (“SEG”)—widely recognized as the principal
`
`international society in the field—since 1993. I was President of the Australian
`
`state chapter of the SEG twice, in 1986 and 1993. In addition to SEG, I have also
`
`been a member of the Society of Petroleum Engineers (SPE) since 1994 and the
`
`Petroleum Club of Western Australia since 2009, of which I am currently a Board
`
`Member. From 2006 to 2012, I was a Board Member and Education Scholarship
`
`Committee Chair of the West Australian State Government Minerals and Energy
`
`Research Institute (MERIWA).
`
`III.
`16.
`
`COMPENSATION AND RELATIONSHIP TO THE PARTIES
`
`I am being compensated at an hourly rate of three hundred and fifty
`
`dollars ($350), plus expenses, for the time I spend in Australia studying materials
`
`and issues associated with this matter and providing testimony, and six hundred
`
`twenty five dollars ($625) for the time I spend on this matter outside Australia.
`
`
`
`8
`
`

`
`
`
`This is my standard consulting rate. I am an independent party and my
`
`compensation is not contingent upon the outcome of this matter.
`
`17.
`
`It is my understanding that WesternGeco L.L.C. (“WesternGeco”), is
`
`the assignee of the ’607 Patent. Prior to this matter, I have not been employed or
`
`retained by WesternGeco or PGS. I own no stock in WesternGeco or PGS, and am
`
`aware of no other financial interest I have with those companies.
`
`IV.
`
`LEGAL STANDARDS
`18. Although I am not an attorney and do not expect to offer any
`
`opinions regarding the law, I have been informed of certain legal principles that I
`
`relied on in forming the opinions set forth in this report.
`
`A. Claim Construction
`19.
`I understand that for purposes of this matter the terms in patent
`
`claims are to be given their broadest reasonable interpretation in light of the
`
`specification of the ’607 Patent, as understood by one of ordinary skill in the art as
`
`of the priority date of the ’607 Patent.
`
`B. Anticipation
`20.
`I understand that for a claim to be anticipated, a single prior art
`
`reference must disclose to a person of ordinary skill in the art, either expressly or
`
`inherently, each and every limitation set forth in the claim. I understand that
`
`claims are unpatentable if they are anticipated by the prior art.
`
`
`
`9
`
`

`
`
`
`C. Obviousness
`21.
`I understand that even if a claim is not anticipated, an invention that
`
`would have been obvious to a person of ordinary skill at the time of the invention
`
`is not patentable. I understand that obviousness is determined by considering
`
`several factors, including: the state of the art at the time the invention was made;
`
`the level of ordinary skill in the art; differences between what is described in the
`
`art and the claims at issue; and objective evidence of nonobviousness (such as
`
`commercial success, long-felt but unsolved needs, failure of others, and
`
`unexpected results). I understand that claims are unpatentable if they would have
`
`been obvious in view of the prior art.
`
`D.
`
`Person of Ordinary Skill in the Art
`22.
`
`I have been informed that a person of ordinary skill in the art is a
`
`hypothetical person who is presumed to have known all of the relevant art at the
`
`time of the invention. I have been informed that a person of ordinary skill in the
`
`art may possess the education, skills, and experience of multiple actual people who
`
`would work together as a team to solve a problem in the field. I have been
`
`informed that factors that may be considered in determining the level of ordinary
`
`skill in the art may include: (1) the educational level of the inventor; (2) type of
`
`problems encountered in the art; (3) prior art solutions to those problems; (4)
`
`
`
`10
`
`

`
`
`
`rapidity with which innovations are made; (5) sophistication of the technology; and
`
`(6) educational level of active workers in the field.
`
`23. On the basis of my consideration of these factors and my
`
`experience in solving problems in the area of marine seismic surveys for decades,
`
`including my familiarity with the education, expertise, and experience of the teams
`
`that devise solutions to those problems, I have been asked to opine as to the person
`
`of ordinary skill in the art to which Claims 1 and 15 of the ’607 Patent are directed.
`
`In my opinion, such a person of ordinary skill in the art should have a Master’s
`
`degree or Ph.D. in ocean engineering, mechanical engineering, geophysics, applied
`
`physics, or a related area, who has preferably taken coursework in hydrodynamics,
`
`advanced control systems, and other related fields. Additionally, the person should
`
`have at least three years of experience designing and/or operating marine seismic
`
`surveys, as well as significant experience aboard marine seismic survey vessels
`
`during the course of several marine seismic surveys.
`
`V. SUMMARY OF OPINION
`24.
` It is my understanding that PGS requests Inter Partes review of
`
`Claims 1 and 15 of the ‘607 Patent, titled “Seismic Data Acquisition Equipment
`
`Control System,” which was issued to Oyvind Hillesund and Simon Hastings
`
`Bittleston on July 25, 2006, and has been assigned to WesternGeco. It is my
`
`
`
`11
`
`

`
`
`
`opinion that Claims 1 and 15 would have been well known and obvious to a person
`
`of ordinary skill at the time of the October 1, 1998 priority date.
`
`VI.
`TECHNICAL BACKGROUND
`A. Overview of Marine Seismic Surveying
`
`25. The ’967 Patent is directed to marine seismic surveying technology.
`
`Marine seismic surveys use reflected sound waves to determine geological
`
`properties of the earth’s subsurface. Seismic surveying ships (also known as
`
`vessels) tow equipment referred to in the industry as “seismic sources” or “guns”
`
`to create small, controlled explosions underwater. The explosions generate
`
`acoustic sound waves that travel down through the water, penetrate the ocean floor,
`
`reflect off geological formations in the earth’s subsurface, and travel back towards
`
`the seismic vessel. The reflected acoustic signals are recorded by seismic receivers
`
`known as “hydrophones,” which are towed behind the vessel in long cables called
`
`marine seismic “streamers.” Because recorded sound waves have different
`
`properties depending on the geology of the ocean’s subsurface, the acoustic signals
`
`recorded by the hydrophones provide information regarding characteristics of the
`
`ocean’s subsurface, including evidence about the existence of oil and gas.
`
`26.
`
` In modern marine seismic surveys, a towing vessel will typically tow
`
`a plurality of streamers in a large areal spread known as an “array.” Each streamer
`
`in the array contains groups of hydrophones located at pre-determined intervals
`
`
`
`12
`
`

`
`
`
`along the streamer. The acoustic data acquired by each hydrophone group is
`
`recorded as a function of time and provides information about a two-dimensional
`
`vertical slice of the earth’s surface below the area traversed by the streamer. By
`
`towing a plurality of streamers, the seismic surveyor covers a large area and is able
`
`to record reflected seismic signals at several locations simultaneously. This
`
`technique results in seismic data from various locations that can be combined and
`
`processed by computers to construct a three-dimensional image of the earth’s
`
`subsurface.
`
`27. Below is a graphical depiction of a modern marine seismic survey
`
`system:
`
`
`
`28. This figure depicts a survey vessel towing four streamers, each of
`
`which contains hydrophones to record seismic data that reflects off the ocean’s
`
`subsurface, and one air gun array (the acoustic source). This multiple-streamer
`
`
`
`13
`
`

`
`
`
`seismic surveying system became commonplace beginning in the late 1980s. See
`
`Ex. 1043 (Brian J. Evans, A Handbook for Seismic Data Acquisition in
`
`Exploration (David V. Fitterman & William H. Dragoset, Jr. eds., 1997))
`
`(“Evans”) at 250.
`
`29. Seismic data are recorded on a shot-by-shot basis. In a typical marine
`
`seismic survey, the vessel will travel at approximately five nautical miles per hour
`
`and fire a shot from one or more seismic sources approximately every ten seconds.
`
`The data recorded by each hydrophone group for each seismic shot is known as a
`
`“trace.” With each “shot,” the seismic source emits acoustic signals (i.e., sound
`
`waves) that are reflected at different points on the ocean’s subsurface. These
`
`signals are received by the various hydrophones on the towed streamers, as
`
`depicted below:
`
`
`
`See Ex. 1043 (Evans) at 9.
`
`
`
`14
`
`

`
`
`
`30. For each shot or “trace,” the hydrophones record the reflected acoustic
`
`signals as a function of time. Each hydrophone group occupies a different location
`
`and thus, for each shot, will record different acoustic signals at different positions.
`
`The recorded data from each hydrophone group for each shot are then sent from
`
`the streamers back to the towing vessel via a communications line that may be
`
`comprised of twisted pair cables or, in more modern implementations, fiber-optic
`
`lines. This shot-by-shot process is repeated continuously during seismic surveys,
`
`resulting in a vast amount of seismic data being transmitted to the vessel. The
`
`seismic data acquired during a survey are maintained on the towing vessel by an
`
`on-board computer or other storage device, along with data reflecting the position
`
`and time the signals were received. This data can later be processed to create a
`
`three dimensional image of the earth’s subsurface in the surveyed region.
`
`31. Marine seismic surveys are carefully planned in advance. Marine
`
`seismic survey data are acquired and organized using a process known as
`
`“binning.” When designing and conducting a three-dimensional marine seismic
`
`survey, the area of the ocean subsurface being surveyed is represented as a grid.
`
`Each cell in the seismic survey grid is called a “bin.” In a conventional 3D marine
`
`seismic survey, the survey plan calls for the streamers to traverse the survey area
`
`grid in straight lines back and forth, creating parallel lines of seismic data
`
`coverage. As practitioners in the marine seismic data acquisition field have long
`
`
`
`15
`
`

`
`
`
`recognized, one of the primary goals of 3D marine seismic data acquisition is to
`
`conform the actual survey to the survey plan’s specifications, including
`
`maintaining the streamers’ positions along the pre-planned designated course,
`
`thereby producing the desired quality and efficiency of the survey as planned. See,
`
`e.g., Ex. 1011 (U.S. Patent No. 4,033,278) (“Waters”) at 2:15-36; Ex. 1010 (U.S.
`
`Patent No. 4,404,664) (“Zachariadis”) at 1:16-40; Ex. 1004 (U.S. Patent No.
`
`5,790,472) (“Workman”) at 1:10-11 (“During a typical marine seismic survey a
`
`seismic vessel traverses programmed tracks . . . .”).
`
`32. The graphic below depicts (without the streamers, for ease of
`
`understanding) a survey area divided into bins. Although their size can vary, bin
`
`sides typically measure about 10-25 meters in length. Ex. 1044 (E. J. W. Jones,
`
`Marine Geophysics (1999)) at 89. Also depicted (but not to scale) is the vessel
`
`conducting the survey. A typical vessel would be about 100 meters long and 25-40
`
`meters wide.
`
`
`
`16
`
`
`
`

`
`
`
`33. As part of the survey design process, seismic surveyors pre-determine
`
`a minimum number of trace data points that they must sum together in each bin to
`
`obtain the desired seismic data quality. If the surveyor does not obtain the
`
`minimum data points required for a particular bin, there will be data of inadequate
`
`quality or simply gaps in the survey data. The presence of inadequate data quality
`
`or gaps often requires the survey ship to repeat the survey over those areas to fill
`
`the bins. The process of re-acquiring seismic data, known as “in-filling,” is very
`
`time-consuming and expensive. See Ex. 1043 (Evans) at 254. Gap or inadequate
`
`data problems were frequently known to occur when currents cause the streamers
`
`and their hydrophones to veer off course from their pre-planned paths, so that in
`
`certain bins, the hydrophones do not record as many data points as planned,
`
`desired, or required. Ex. 1045 (W.R. Cotton & J.I. Sanders, The Reality of Trace
`
`Binning in 3-D Marine Surveying (1983)) at 565; ¶¶ 43 (Hedberg), 48 (Weese), 51
`
`(Waters), 54 (Zachariadis), 63 (’636 PCT) infra.
`
`34.
`
`In addition to ensuring that sufficient traces are recorded in each bin,
`
`seismic surveyors also desire to have the data points as evenly distributed in the
`
`bin as possible. Having the data points unevenly or irregularly spaced within a
`
`bin—often the result of streamers (in which the hydrophones are contained)
`
`veering off the planned course—creates “uneven illumination or incomplete
`
`illumination of the subsurface.” See Ex. 1046 (Biondo L. Biondi, 3D Seismic
`
`
`
`17
`
`

`
`
`
`Imaging (2006)) (Bondi) at 123; see also Ex. 1047 (Christopher L. Liner, Elements
`
`of 3-D Seismology (1999)) (Liner) at 104-05; Ex. 1043 (Evans) at 238.
`
`35.
`
`It was well recognized before October 1, 1998 that this irregular
`
`spatial sampling and resultant uneven or incomplete illumination of the subsurface
`
`reduces the quality of the survey data and makes it more difficult and expensive to
`
`process the data. See, e.g., Ex. 1048 (Gerald H.F. Gardner & Anat Canning,
`
`(Effects of irregular sampling on 3-D prestack migration, SEG Abstracts (1994))
`
`at 1553-56; Ex. 1043 (Evans) at 238. For example, where there is regular spatial
`
`sampling in a survey, the individual seismic data points in adjacent bins are
`
`generally one bin length apart. But, if there is irregular spatial sampling, such as
`
`where the data points collect on one side of a bin and on the far opposite side of an
`
`adjacent bin, it results in a substantial amount of space between seismic data
`
`points, creating large gap areas with no data. On the 3D image, that area could
`
`show up having less detail than the rest of the survey, thereby reducing the quality
`
`of the overall survey data. See Ex. 1046 (Biondi) at 123. This problem is referred
`
`to as “spatial aliasing”:
`
`Spatial aliasing is an effect of [data point] spacing
`relative to frequency, velocity, and slope of a seismic
`event. With adequate [data point] spacing, the points
`along a seismic event are seen and processed as part of
`the continuous event. When [data point] spacing is too
`
`
`
`18
`
`

`
`
`
`coarse, individual points do not seem to coalesce to a
`continuous event, which confuses not only the eye but
`processing programs as well. This can seriously degrade
`data quality and the ability to create a usable image.
`
`
`Ex. 1047 (Liner) at 104.1
`
`36. Irregular spatial sampling caused by irregular streamer positioning
`
`also has “a detrimental effect” on data processing, thereby making it more difficult
`
`and expensive to process the data. Ex. 1047 (Liner) at 104-05; Ex. 1046 (Biondi)
`
`at 123-24. Accordingly, though obtaining the prerequisite number of seismic
`
`traces within each bin is important, that alone does not ensure adequate data
`
`quality. To avoid these degradations and distortions in the data, seismic surveyors
`
`seek to position streamers (and their hydrophones) to achieve regular spatial
`
`sampling in bins, thereby avoiding holes or uneven distributions of seismic traces.
`
`
`1 Although Liner was writing in 1999, he was summarizing what was previously
`
`known in the field about spatial aliasing. Indeed, Liner cited prior art that
`
`describes the spatial aliasing problem. See, e.g., Ex. 1049 (Christopher L. Liner &
`
`Ralph Gobeli, Bin Size and Linear v(z), Society of Exploration Geophysics
`
`Technical Program Expanded Abstracts (1996)) at 47. I also wrote about this
`
`problem in my book, see Ex. 1043 (Evans) at 238, and noted the problem in my
`
`class notes in the late 1980s.
`
`
`
`19
`
`

`
`
`
`B. Streamer Steering Overview
`37. Effective streamer steering has long been recognized in the field to
`
`provide many benefits for seismic surveys. During the seismic survey, the
`
`streamers are typically intended to remain straight, parallel to each other and
`
`equally spaced. Due to environmental factors such as wind and sea currents,
`
`however, seismic streamers frequently bow and undulate, thereby introducing
`
`deviations into this desired path and shape. As explained above, without the ability
`
`to control the streamers, deviations from desired streamer positions can create gaps
`
`in the seismic data coverage, reducing data quality and the efficiency of seismic
`
`survey operations. See Ex. 1013 (International PCT Application No. WO 98/28636
`
`) (“‘636 PCT”) at 2; Ex. 1004 (Workman) at 1:28-41; supra ¶¶ 31-36. Therefore,
`
`an advantage of being able to steer a streamer laterally is the ability to ensure that
`
`streamers remain straight and parallel, along their intended path of travel,
`
`throughout the seismic survey.
`
`38.
`
` Streamer steering also was known to be desirable to avoid
`
`accidents that could damage the survey system. If streamers veer substantially off
`
`their intended course, for example due to local currents, they can become
`
`entangled and thereby disabled, which creates significant expenses. The efficient
`
`conduct of the survey, with minimal downtime, is essential to the profitable
`
`conduct of the survey. See Ex. 1013 (‘636 PCT) at 2.
`
`
`
`20
`
`

`
`
`
`39. The ability to control the depth of the streamers also has long been
`
`recognized to be desirable. Streamers are typically towed at a constant depth of
`
`approximately 10 meters. Maintaining streamers at a constant depth is important
`
`because depth variations between hydrophones in a seismic array introduce
`
`complications into seismic data processing. See Ex. 1008 (U.S. Patent No.
`
`3,605,674) (“Weese”) at 1:41-45 (“In order that the signals received can be
`
`properly and correctly interpreted, the position of the cable relative to the water
`
`surface . . . must be known and maintained as uniformly as possible.”)
`
`1. Streamer Positioning Devices
`
`40. To implement streamer steering, marine seismic surveyors have
`
`developed streamer positioning devices. Generally, streamer positioning devices
`
`are part of the streamer or are attached to the streamer. Below is a depiction of two
`
`prior art streamer positioning devices:
`
`
`
`
`
`
`
`Ex. 1008 (Weese) at Fig. 5; Ex. 1013 (‘636 PCT) at Fig. 1.
`
`41. As seen in the figures, streamer positioning devices—such as birds,
`
`paravanes, and tail buoys—typically have at least one water-deflecting surface
`
`
`
`21
`
`

`
`
`
`(e.g., a wing, fin, or rudder) that can be positioned at different angles to adjust the
`
`streamers’ depth and/or control the streamers’ lateral movement. Streamer
`
`positioning devices were disclosed in the art by at least the 1960s.
`
`2. Control Systems for Streamer Positioning Devices
`
`42. Control systems capable of controlling streamer positioning devices
`
`by calculating and implementing desired positions changes have also been long
`
`known in the art. A control system is “an interconnection of components forming
`
`a system configuration that will provide a desired system response.” Ex. 1035
`
`(Richard C. Dorf & Robert H. Bishop, Modern Control Systems (8th ed. 1998))
`
`(“Dorf and Bishop”) at 2. In general, control systems receive inputs and process
`
`them to create outputs. Id. Simply put, streamer positioning devices cannot
`
`effectively steer streamers without some sort of control system, so it is no surprise
`
`the art has disclosed streamer positioning control systems for as long as it has
`
`disclosed streamer positioning devices.
`
`43.
`
`In his 1971 patent titled “Marine Seismic Exploration,” Ronald M.
`
`Hedberg recognized the well-known challenge that errors in seismic data would
`
`ensue when “drift or displacement” of a streamer is caused by marine currents. Ex.
`
`1007 (U.S. Patent No