CA1168342A - Ground position controller and method for automatically indicating and recording parameters that spatially define locations of seismic exploration spread and source arrays - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention relates to a ground posi-tion controller (and method) for generating, formatting and recording information for insuring the integrity of field shooting and recording operations.

Description

GROUND POSI'rION CONTROL,r.l'E~ ,~ND ML!T~IOD FOR
AUTOMATICALLY INDIC~TING ANI~ RE(,'ORDIMG
PARAMETERS Tl-IAT SPATIAL,LY l:)EFINE LOCA'rIOl~S
05 OF SEISMIC EXPLORATION SPR~,Ar~ AND SO~RCE ~RRAYS

: SCOPE OF 1'1-11~ V~N'I':ION

This invention relates to seislrlic explorcltion and more ~artlcularly to Inethods and apparatl1.s for insuring inteyrity of field shootiny and reco~ding opera~
tions durillg cxp]oratiorl ~or hy(lrocarborls and the like.
In one aspect, the present invention provides for dynamic control of the field shooting and recordirlg operations so that the latter actually correspond to the advaneed specifications Eor those operations; as a result, recording operations can be coordinated with the speci~ied shooting (or vibrating) operations. In aecordanee with another aspect, the present invention provides for the generation and recording of data including array anc3 source geometry information on a reeording media as header data in addition to the reeording of seismie data repre-senting aeoustie signals reeeived as -the eonsequenee of shooting (or vibrating) operations.
BACKGROI]ND OF T~IE_INVFNTION
25In seismie exploration, proposed prescriptions for shootin(3 (or vibrating) and reeording operations rnust be followed -- preeisely -- in the field, partieularly in fielcl teehniques involving so-ealled Common Depth Point Reeording (or CDPR) operations ln whieh ehangincJ sets of sensors were used in assoeiation with successive shots to provide multiple staeked recordings. (In all of the following teachings, the words "shots" and "shooting" will be used for the part of the operation in whieh the sound waves are generated and sent down into the sub-surface.
It will be appreciated, however, by those skilled in the art, that the sarne teachings apply where the sound waves are generated by large vibrators at the surface rather than by explosive shots.) ~0 ln the CI~PR proccss, sensors and erleryy sources are positioned at a first seLies of spatiall~ (geollletri-05 ally) relate~d locations, to produce a first record. ';ub~sequent records are tllerl made with the s(?nsors an-3 thf~
energy source occupying new locations. Ilowever, the sen sors ancl eneryy source norTnalLy maintairl the salne reLative spatial relationship to each other during the Eiek~ ope~a-tions.
Advancemellt oL the sensor locatiorls (in cnl?Roperations) employ a technique comrllonly knowll as "roLl-alollg". Relative advancelnellt o the sensor array is common:Ly done in a very rapid manner usinc3 a switching device callec] a rollaloncJ switch (such as shown, e.g., in my U.S. Patent 3,61~,000, November 2, 1971 or "Rollalong Switch"), in which a large number of sensors can be COTl-trollably provided at any programrned interval along the recording line. Through the use of multiple pair cables extending along the line, these sensors are connected into the input receptables of the rollalong switch. The design of the switch permits a certain number of the sensors, called the "active" array, to be interconnected to the input of the geophysical seismic recorder and keeps track of t~le position of one end of the active array relative to the number of recording channels available (say, any posi-tion within l-in-60 channels). Not only can the switch select any contiyuous group of sensors, Erom the total number positioned along the line, as the "active" array or spread, but it can also add gaps in the active spread using one or more "inactive" groups as the gapping rnembers, a technique usually used when a large energy source is positioned at the center of the active array.
(A l'gapped" array for a 24-sensor record, for example, 35 consists of sensors 1 through 12 and 15 through 26 with sensors 13 and 14 left disconnected by the rollalong switch.) Computer processing oE the CDPR field data (now commonly done by large centralized computer facilities) requires not only accurate time-versus-amplitude seismic 01 3_ rc?flection data but also requires "housekeepirl<J" data describing associated source and sensor geornetry as the 05 former was collected. These latter data consist o~, inter a_ia, positional locations for every sensor in each "active" array during the recording sequerlce, the location of the eneryy source, and the location and sizc of the gap (if any). To provide the above, the usual Eie:Ld procedure 1~ is to determine the groun(3 locations hy survcy prior to the recordiny operations. 'I'he location al-l(l direction or:
the line is reEerellced to know geographic locations or yeodetic survey points. The Location of each sensor (or sensor group) and energy source is surveyed in and rnarked with a survey stake having an identification number repre-senting a c3round location. These locations are written down in the survey log for that particular seismic line.
The surveyor's log thus contains part of tht? gC?olnetriCa]
data that must be added to the seismic data after the 2U latter has been recorded and is ready for processing.
Another requirement of the geometrical data is developed during the recording process. It relates to data entered into the "observer's log". (The operator of the seismic recordiny system is commonly called the "observer".) The observer's log contains, for each record sequence, the spatial extent of the active sensors usually identified by yround locations of the sensors at each end of the active array. In the event that the active array contains a gap, the location of the gap will be specified relative to adjacent active sensor locations. The observer's loy also contains the location of the energy source for each record. In some cases, when a presurveyed line is recorded, ~he energy source cannot be located at the location designated for it duriny the survey. In these situations, the shot location from the observer's log must be used in processing instead of the original survey data. The observer's log also contains information that infers or describes spatial irregularities in the active array imposed by Eield conditions wllen the line is recorded.

. D ~ ,r ~ s previously inciicated, thr rollalony switch tracks the position of active array (~or identifying tlle 05 location o~ the "active" sensor array ineluding yap).
While some rollalong swlteh units provide for transferring such array data directly to t~le Eield reeorder (recogniz-able as header data on the digital seismic tape), these data are not in terms of true~ c~roun(l location/ but in an arbitrary nurnberilly sec~lletlce, relative to a partieular recording vehicle location. '[`he true grollnd location o~
the recording vehicle must there~ore be ente~ed into the observer's loy in order to convert rollalong switch posi-tions to true ~round locations.
Tl-~e foregoing description of geophysical seismie data reeordiny operations indieates eonelusively that the recording o~ seismic refleetion data must be supported by aecurate and suffieient eorrelative data so as to aceu-rately define spatial souree ancl sensor geometry relative to a permanent geographieal loeation. It also indieates that separate types of eross-eheeking materials, for doeumentation, are needed as the data is colleeted, ineluding the steps of generating, Eormatting and displaying spread and sound geometries for both present 5 and next-in-time shooting and recording sequences.
SUMMARY OF TE~E INV~NTION
One particularly useful embodiment of the inven-tion eomprises a ground position controller for generat-ing, formatting and recording information for insuring the integrity of field shooting and reeordiny operations. The controller includes sets of multi-digit displays dynamie-ally eontrolled by a mieroeomputer system inter-connected to the exploration system. Before the source is activated and spatial ~eometrieal parameters reeorded, the operator examines -- colleetively -- all displayed data and cross-checks those results with prescribed instructions; then, after he signals that the data do represent the desired field operations by e.g., activating a transmission linkaye swit(ll, the displayed data (both encoded and eal-~0 culated) can be transferred as header data to a field recording unit in series with the control~Ler~ Prior to transfer, the controller also formats the data in a form required for proper annotation of the seismic record. As a result, the final seismic record contains data representing original array/source geometrical data that can be unambiguously associated with the recorded seismic information received from the subsurface as a result of the particular operational sequences. At the end of the recording cycle, the controller generates a series of new data: (i) new shooting and spread geometries, and (ii) positional skips tgaps) of the array. Then the sequence can be repeated. Thus, the present invention translates original operational instructions into a presentation accurately suitable for annotation of the seismic data, such data being in a form that the field operator can quickly cross-check via displays before operations are concluded. Also, the present invention aids the operator in cross-checking and cross-listing data so that any deviation from the prescribed field procedure can be detected and corrected. Finally, coded descriptions of actual operations 2a can be unambiguously associated with recorded seismic data received from the subsurface as a result of particularly-described field operations.
Various aspects of this invention are as follows:
Method of calculation, storing and recording positional data associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey, said positional data being generated as bits of digital data stored in a microcomputer system including a microprocessor unit (MPU), memory units, and a series of display/storage and switching devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in " Y~

-5a~
exploration activities are xeduced, and annotation of exploration activities is automatically aclded, comprising (a) establishing in digital format via said microcomputer system, array geometry and exploration parameters that allow annotation in sequence of exploration activities along said line, (b) automatically displaying at said display/storage and switching devices of said system, at least a portion of data of (a) an alpha-numeric form for operator e~amination and correction, if requ.ired, and (c) automatically recording said portion of data of (a) as header data so as to provide full annotation of exploration activities whereby errors in such exploration activities can be discovered and accounted for.
Method of calculating, storing and recording positional data associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at ~nown locations along a line of survey at the earth's surface, said positional data being generated as bits of digital data in a microcomputer system including a microprocessor unit (MPU), memory units and a series of display/storage and switching devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in exploration activity -- both pre-activation and past-release of energy f.rom said source -- are substantially reduced, comprising (a) encoding and automatically storing additional digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line, (b) automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, -Sb-(c) automatically generating via said microprocessor system further additional data related to array parameters based in part on data encoded at (a), and previously stored data related to exploration parameters, Id) displaying at said display/storage and switching devices of said microcomputer system at least a portion of said new array parameters of (c) for operator examination and correction, if required, and (e) automatically recording portions o~ said displayed data of steps (b) and/or (d) as header data so as to provide full annotation of exploration activities whereby errors in such activities can be pinpointed and taken into account.
A ground position controller for manipulating calculating, storing, displaying and causing recordation of positional data, associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source ~-are substantially reduced, said positional data being generatedas bits of digital data using a microcomputer system comprising a microprocessor unit (MPU), memory units, and a series of display/storage and switching devices interconnected to each other and to a digital field system (DFS) via a system bus, said display/storage and switching devices including separate encoding means for automatically encoding digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line of survey, separate display means for automatically displaying at least a portion o~ said encoded data in alpha-numeric form for operator examination and for correction, if required, before activation of said source, and separate switch sequencing means, connected to said microcomputer system and to said DFS for initiating, on -5c~
command, an operational signal leading (i) to the recording of portions of said encoded and disp].ayed data onto magnetic tape at a recorder unit of said DFS, and subsequently (ii) to activation of a seismic source of said array, said displayed data at said separate display means being automatically generated via said microcomputer system using data related to array parameters based in part on encoded data, previously stored data related to exploration parameters, and newly generated array parameters whereby errors in exploration activities can be substantially reduced; said recorded data being associated with source and array positions vis-a-vis said known geographical positions along said line of survey.
Method of calculating, storing and displaying positional data, associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, said positional data being generated as bits of digital data in a microcomputer system including a microprocessor unit (~PU), memory units and a series of display/storage devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source -- are substantially reduced, comprising:
(a) encoding and automatically storing additional digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line, (b) automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, (c) automatically.generating via said microcomputer system further additional data related to array parameters based in .F ~ J
-5d-part on data encoded at (a), and previously stored data related to exploration parameters, and (d) displaying at said display/storage devices of said microcomputer system at least a portion of said new array parameters of (c) for operator examination and correction, if required, whereby errors in exploration activities can be substantially reduced, pri.or to activation of said source of said array.
A ground position controller for manipulating, calculating, storing and displaying positional data, associated with a diyital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source --are substantially reduced, said positional data being generated as bits of digital data comprising a microcomputer system including a microprocessor unit ~MPU), memory units and a series of display/storage devices interconnected to each other and to a digital field system (DFS) via a system bus, said display and storage devices including separate encoding means for automatically encoding digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line o~ survey, said separate display means for automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, said displayed data at said separate means being automatically generated via said microcomputer system using data related to array parameters based in part on encoded data, previously stored data related to exploration parameters, and newly generated array parameters whereby errors in exploration activities can be substantially reduced.

-5e-These and other advantages and functions of the present invention will become evident to those skilled in the art having a reading of the detailed description of speclfic embodiments thereof, following a brief description of the appended drawings.
DESCRIPTION OF THE DRA~IINGS
FIGS. 1 and 2 illustrate an exploration system incorporating the present invention in which an energy source and an array of sensors (connected to a recording truck) are illustrated.
FIGS. 3 and 6 are block diagrams of the ground positioned controller of the present invention used within the exploration system of FIGS. 1 and 2.
FIG. 4 is an isometric view of a display panel of the controller FIGS. 3 and 6.

p~

~;`IG. 5 is a block diac~ram oL a rnicroprocessor urlit of the controller o(- F:tGS . 3 and 6.
05 FIG. 7 is an imaginary r-ndition of heac'~er data encoded onto maynetic tape usincJ the contro]ler of the present invention in association ~ith the recording unit of the exploration system of FIGS. 1 and 2.
FIG. 8 is a block diagram of ~)ortions of the circuitry comprising the controller of r'lGS. 3 and 6, and recorder unit used in the exploration system of E~'IGS. 1 and 2.
~I(.S. 9A-9C are Elow diagrams which illustrate thf- method of the present invention.
L5 FIG. 10 is a partially schematic diagram of the recorder unit of FIG. 8 illustratiny a secluence of opera-tions, associated therewith.
DE~CRIP'rION OF
PREFERRE~D EMBODIMENT,S OF THE INVE 'ION
FIG. 1 illustrates operation of seismic explora-tion system 9 of the present invention.
As shown, system 9 ineludes digital field systern ( DFS) 10, housed within recording truck 11 and electric-ally interconnected via a multiwire geophyslcal cable 12 25 to an array of sensors 13 positioned at the earth's sur-face 14.
Ground locations 15 are represented as sur-rounding both the array of sensors 13 and seismic energy source 16, all positioned along the surface 14. As pre-viously mentioned in the C~RR collection process, theground locations 15 would, more likely than not, have been previously surveyed prior to implementation of the seismic surveying operation along the line of survey 17 in the direction of arrow 18. Hence, each of the locations 15 can be designated by a particular position number (or P number) along the line 17. The P numbers set forth in FIG. 1 include the numbers 300, 301... 329. Also, the number of sensors 13 forming each array (as the data is ~0 ()1 -7-collected) is identified by the seqllence nurllbers N, N-~l...
N+M designating the length of the active array as the 05 sensors 13 are advanced in the direction of arrow 1~.
Annotating the positions of the sensor arr.lys is aided by tlle fact ~hat each sensor is associated with a particular clata channel 1, 2...K of the DFS lO as the data is collected. F`or usual operations K can be 24, ~3, 60, 96, 120, etc., as recluired, althoucJh, of course, t:he pre-sellt invention is not limited to a partic~l]ar cllclnrlel capacity number, but can be varied to accornmodate any field arrangemerlt. ~ach sensor position and each source location can be indicated using the ground pc~sitiorl con-~S troLler 20 oi the~ present invention in conjunction withrecording ~nit 21 of the DFS 10.
~ tG. 2 illustrates ground position controller 20 in Inore detail.
Briefly, the yround position recorder 20 operates in the field to insure integrity bet~Jeen pre-scribed and actual field shooting and recording operations by a series of steps, narnely, storing, manipulating and displaying data related (i) to field positions of the source and sensor array by position number, (ii) to array and source geometrical locations (both present and next-in-time) based on field ~eometrical algorithms and (iii) to recording array and source parameters so that realistic annotation of the subse~uently collected seismic data, can be made. For -these purposes, the operator utilizes encoded data provided initially by him using encoders 26, manipulated results generated by the controller 20 based on part in stored relationships within the rnicrocomputer 25, and finally indicating geometrical data set forth at displays 27 and as header information at recording unit 21.
Since the present invention deals conveniently ~ith the CDPR process, the array of sensors 13 and source of energy 16 are continually "rolled for~ard" in the 3~ 3, 01 _g_ direction of arrow 13 usi.ng rolla:long switch 22. That is to say, after the seismic data has been recorded at the 05 digital tape recording unit 21 (after amp:Lificatioll by amplifier 24), the array of sensors 13 (and source 16) located at a first series of positions P as shown, are "rolled for~"ard" in the direction o:E arrow l~. Note that the changing of the active array pattern of E'LC. 1 in the 10 aforelnentioned manner is identified by the array sequence desigrlated 1`~1~ N-~l... N+M~ as previously mentiorled. But, the array and source geometry is always ]cnown at the recording truck 11 provi.ded the positional locations 300, 301, 302...P of FIG. 1 for the particular active array N, 15 N-rl . . . N+M are correctly identified and recorcled during each recor-ling cycle, via operation of the ground position controller 20 of the present invention; oi~ particular im~ortance is the manipulation of data as.soc;ated with the fiek] geometry of the sensors 13 and source 16 via geo-:~() metrical and perEormance algorithms stored within mi.cro-computer 25 of the controller 20.
As previously mentioned, microcolnputer 25 is used to predict correct array positions as the rollalong switch 23 switches between "active" and "inactive" arrays 25 of sensors. The microcomputer 25 can also interact with the rollalong switch 22, provided the latter is capable of accepting the multi-bit codes conventionally generated by the microcomputer 25. (In this regard, an approved roll-along switch is manufactured under the tradename "Rola-30 long Switch", by Input-Output, Inc., ~ouston, Texas, and consists of a series of contac-ts attached to a central shaft of a stepping motor controlled via a digital input code from the microcomputer 25.) Rollalong switch 22 usually includes a display 35 (not shown) associated with one or two of the locational positions of the active array of sensors 13. Such dis-play, of course, changes as the active array changes sequential pattern in the manner of N, N+2... N-~M~ as shown in FIG. 1. The rollalong switch 22 also includes a 40 digital generator (not shown) for generating a second 0l ~ 9~

multi-bit code indicative o~ the position P oL a mernber o~
the sensor array as '-neader inclicia at the recorder 21.
05 ~lowever, as previously mentiol~ed, the latter di~Jital code represents only an arbitrary nulllber arld is not a true yeodytic location.
FIG. 3 illustrates microcorllputer 25 of con~
troller 2n in stlll more detail.
As shown, the microcornputer 25 includes a systeln bus 28 used to connect encoder-s 26 and d i:;play-; 27 via I/O
interfacillc3 array 3~ to microE)rocessor unit 30 (MPU) oE
the microcornputer 25. Also connected via the bus 2~3 and ports 29 are interrupt controller 31, RAM 32, ROM 33 (in addition to I/O inter~acing array 34) which operates in conventional fashion to calculate, rnanipulate, store and display position data associated with the exploration operation. Note that the I/O array 34 not only links thc~
MPU 30 witn the encoders 26 and displays 27, but it is also used to provide data to the printer 35 under control of MPU 30 to generate a permanent record of the displayed data at dispLays 27, if desired.
Bus 23 essentiallv comprises three separate buses, a data bus, an address bus and a control bus. The data bus is conventional: it not only carries information to and from MPU 30, but it is also used to fetch instructions that have been stored irl ROM 33, as required, as well as carries data frorn/to the encoders 26 and dis-plays 27 of FIG. 2, by way of (or independent of) RAM 32.
Addressing segments oE the data is the annota-tions function of the address bus. It is capable of selecting a location in RAM 32 or ROM 33 or a particular address in the MPU 30 when appropriately signaled, say by interrupt controller 31. The eontrol bus controls the sequencing and nature of the operation using common selector commands, e.g., "Read", "Write", etc.
Additionally, it should be noted, the system interrupts are usually carriec] via the control bus to implement the scheduling and servicing of different ports, 40 as required by operations. -rn the present invention, 3~

nl -10-interrupt controller 31 nalldl.es scvc?rl (7) vectored prior--ity interrupts for the MPU 30, as explained below, 05 includinc3 an end-of-record interrupt (~O~) generatecl by the digital field systern 1(), FIG. 1, to indicate the e~nd of the collection cycle, and to initiate operations in tne next-in-time cycle.
:[n genera.L, in scrviciny the interrupts, pr-.ser-vation of program status is required and is easily carrie(lby the i~l?~ 30. Si.nce thc corltrollcY 3:L :is both vectored an(l priority oriented, it has the respons,ibility o~
providing vectored interrupts to the MPU 30, oi- identi-fying the nature of the interrupt, (or its branchi.ncJ
address) and of establishiny priority between competing interrupts.
In particular in servicing the EOR i.nterrupt, the steps set forth in FIGS. 9B and 9D are execu~:ed to bring about automatie updatinq of the array and source geometry to achieve the next-in-time colleetion of data, based in part on the field algorithms eontained in equa-tion sets I, II, III or IV set Eorth below.
FIG. 4 illustrates the nature of the data provided at encoders 26 and displays 27.
The operator ini-tially ealibrates positions of the exploration array and souree with previously surveyeci geographical stations. Information has been already encoded via the eneoders 26 for use by microcomputer 25 before operations begin. E:ncoded data at encoders 26 includes:
(i) truck location (vis-a-vis survey stations of known geographic location) encoded at encoder sub--element 40;
(ii) slave truck location (if applicable) encoded using encoder sub~element 41;
(iii) reference station location (where the end of the spread is initially positioned) encoded via encoding sub-element 42;
(iv) initial location of the energy source encoded using encoder sub-element 43;

(v) the number of ;hots or sweeL)s erlco~ d at sub-elernent 44;
05 (vi) the initial yap position, stored at sub-element 45;
(vii) the gap spaciny enco(led usiny encoder sub-element 46; and (viii) gap roll increment encoded USilly sub-L0 elernent 47.
The operator also has the ;nitial responsibility of encodiny other data which, for the rnost part, does not chan~3e cluriilg the survey. ~n this regar(J, the operator rnay have to only initially encode shot depth and si~e (at sub-elemellts ~1~ ancl 49), shot direction and o~fset (at sub-elements 50 ancl 51) as well as data related to the spread, as to its direction (at sub-element 52) and the distance between groups (at sub-element 53).
Switch arrays generally indicated at 54 and 55 are also set by the operator. Data provided by these switch arrays, relate to two or three possible switch states of tne switches 56-66 which are, for example, related to the type of survey and run conditions occurring after the survey is underway.
[In this regard, the functions of the switches are as follows: Switch 56 specifies line direction;
switch 57 specifies truck rank, i.e. determines if the reference truck is the master (or slave) in relationship with an alternate truck; switch 5~ specifies operations in either a serial or in a parallel mode, the mode being related to whether one or two arrays of geophones are used in-line or parallel to the corresponding source line;
pushbutton switches 59 and 60 relate to start up and to alarm reset functions respectively; switch 59, of course, initializes operations after all synchroniza-tion has ~een completed; switch 60 turns off the audio alarm in the event that a signal of some importance has been generated causing the alarm to also activate; transmit switch 61 "triggers" the energy source, and is operative only after the operator is assured the correctness of the array and 01 -:L2-source positions as displayed at clisp1ays 27; switches f,2 and 63 related to (i) the "tric3yer" link associated with 05 the activation of the source (electrical wire-line or radio) and (ii) whether or not the roll switch 22 (FIG 2) is to be in an active or passive state. Three-position switch 6~ establishes whether or not the operation is to be in a manua], automatic or test mode; update switch 65 operates only when t~le switch 64 is in the manual mode ancl is used (in manual mode) to initiate advances o~ the roll switch so as to c~enerate new groun(l locations for the array after the recordincJ cycle has been completed; and switch 66 is a conventional power-on switch.]
Displays 27 rnay be conventiolla1 L.ED segmented displays except that they are microcomputer Lmplemented.
Primary purl~oses of the displays 27: to provide data to the operator so that determinations as to whe-ther or not the system is ~unctioning correctly can be made, and to allow the operator to act as an independent cross-checker of the correctness of the displayed ground locations. ~I'he data at displays 27 relate for -the most part to the type of run being undertaken and survey conditions.
[In this regard, the nature of the displays 27 is as follows: subdisplays 70 and 71 indicate shot loca-tion and number of shots per location, respectively; sub--displays 72-75 relate to geographic locations of the active array as a function of time; subdisplay 76 speci-fies the position of the slave reference; status subdis-3U play 77 specifies (by code) the occurrence of certainactivities during the exploration operation which may be accompanied by an audio alarm to indicate the immediate need for operator intervention, the meaning of the status code at subdisplay 77 being as set forth below, in Table I.

9~

~BI~ I
Code AC tivity 05 0 Setup for sequence start operation Geometrical mistie

2 Ready for update or update in proyress (i in auto rnode)

3 Roll Switch Moving

4 Roll Switch (Stopped in position) Roll Switch Disabled 6 Slave ReEerenee Code Receivecl 7 I'ransrnisslon Reference Error (slave reference coc3e not reeeived) 8 Load Ref Output At ShiEt Re~ister 9 Transrnit (one bit of ref code) A Gap Set Mistie D Oceurrence of Last Shot lX Beeper On With Status Displayed as to Code :2() 0, 1, .. 9, A, D, alone.
53 Step Roll Switch [lp With Beep on and Code "3"
93 Step Roll Switch Down With Beep on and Code "3".

Explanation of Table I: status code "0" occurs any time that the controller 20 is powered up to cue the operator that all input data at the encoders 26 must then be set. Sequeneing start button 59 terminates the cueing operation; status eode "D" indieates that the last shot 30 position is at hand and thus, the truek loeation and connection station vis-a-vis the array must be changed;
status codes "3", "4", "5" and '!53" and "93" indicate certain roll switeh activities. If there are errors in the programmed e:~ploration aetivity, warning codes are 35 also generated by the status codes "1"; and "7".]
OPERATIONAL s~Qur_E
Assume the operator has initially ealibrated the start-up positions of the array and souree with the sur-veyed locations. As previously inclicated in regard to 40 FIG. 4, this entails encoding of positional data via 0 1 ~

encoders 26 in conjunction with proper settiny of theswitching arrays 54, 55. The result: correspon~-ling shot, 05 spread and associated data appear at the displays 27 due to the interaction of data relationship established through operation oE the microcomputer 25 of FIG. 2. In order to better understand how the present inventiorl uses all data, perhaps a brief overview of the hardware aspect:s of the microprocessor 30 is in order and ls presented below in connection with E'IG. 5.
It should be initially noted that MPU 30 is preferably an Intel 8085 microprocessor, a product of Intel Incorp., Cupertino, California. As i.s well known, it has a microprocessor and controller integrated into a sing:Le chip. It also includes an array of registers 82 tied to an ALU 83 via an internal data bus 84 controlled via control unit 85 Program counter 86 and instructional register 87 have cledicated uses; the other registers, such as accumulator 88, have more general uses. In the 8085, expanded control functions result because the low-eight (8~ address bits have the capability of being mul-tiplexed.
Such operation occurs at the beginning of each instruct-ional cycle; the low-eight address lines appear via ALE
line 89 for control of different elements of the location, including encoders 26, displays 27, and printer 35 through I~O interface array 34 of FIG. 60 As shown in FIG. 6, while the I/O array 34 is conventional, it must be capable of handling a series of 8-bit independently addressable codes. For this purpose, it preferably comprises a multiplicity of ~-bit I/O port chips indepedently addressable via ALE line 89 of FIG. 5 of the MPU 30. Each 8-bit I/O port chip preferably com-prises an 8-bit latch combined with a 3-state output buffer in which each can be separately driven. In deter-mining location of data via address decoder 38, the MPU 30 also must manipulate the data using known geometrical relationships in which encoded positional data can be translated as required, depending on several factors.

Assu~ne the survey has just been started; the operator has ellcoded all pertinellt data via the encoders 05 26. Also switch arrays 54, 55 have been properly set.
Initially the contro:L and reference location ~osition c]dta from encoders 26 (ancl the switch arrays) are fetched by the MPU 30. The MPU 30 next performs the required Inani~Ju-lation of that data to define spatial array arld source geometries of interest in the manrler oE l`[GS. 9A and 9C.
Such mani~ulation of data includes executiorl of the ster>s associated with the ba;ic power-up routine of FIG. 9~ an(l tile sequence start routine o~ F[G. '~, inc:Luding accessing thc calculated data to clisplays 27 Eor operator perusal DATA ARRANGEMEN~S AT DIS _AYS 27 Values of data appearing at displays 27 oE F`IG.
4 are, of col~rse, dependent upon use of certain geometri~
cal equation sets viz. equation .sets [ II III and IV
set forth below, s~ored in the MPU 30 and selectively utilized by the controller 20 as required.
SEQUENCE START EQU TION_SET I
Assume both the ground location numbers and data channel numbers increasing along the seismic line in the direction of arrow 18; accordinyly, the ~ollowing set of equations control operations:

(1) RLSP = REF-NP-TR
(2) END 1 = REF
(3) END 2 = REF-~GPNO~K-l 3~ If GPNO = 0 (4) GAP 1 = 0

(5) GAP 2 = 0 ïf GPNO > 0 (4) GAP 1 = REF^~GPLOC-l (5) GAP 2 = REF+GPLOC+GPNO

(6) ROOM = TR-REF-GPNO^~l -Table II, below, deines the notations used above in connection wi-th the Equation Set I:

TABLE :[I
Notation DEFINIT[ON
_ . _ _ ___ SEILO Eneryy source location S~NO Eneryy source number l0 REF Location of reference sensor ROOM ~lo. of rollalong switch positions available ~or advanciny the clctive spread TR Ground reference for recorder location P~O Number of geophone yroups in the GAP
15 GPLOC Location of the GAP
K Number of data channels in recording system (24, 48, 60, 96, 120, etc).
END 1 Ground location of the geophone yroup inter-connected throuyh the rollalong switch to the first data channel of the recorder.
END 2 Ground location of the Kth data channel GAP 1 Ground locatlon of the data channel below the GAP on the first data channe:L slde.
GAP 2 Ground location of the data channel above the GAP toward the Kth channel.
RLSP Rollalong switch position required for a desired active spread location.
NP Number of rollalong switch positions avail-able minus 1. (N~ ollalong switch must be configured for K-~N inputs and K
outputs.
GL(+) Ground location numbers along the seismic line increasing numerically in the direction in which the active geophone array is advanced for each successive record sequence Notation DEFINIT~ON
.
GL(-) Ground locations numbers decreasing nurneric-05 ally in the direction in which the active spread is advanced.
CH(+) Seisrnic data channel increasing (1 to K) numerically along the active spread in the direction in which the active spread is ac1vanced.
Ci~( ) Seismic data channels numerically decreasiny (from K to 1) in the direction in which the active spread is advanced.
GAP 2 Ground location of the data channel above the GAP toward the Kth channel.
RLSP Rollalong switch position required for a desired active spread location.
NP Nurnber of rollaloncJ switch positions avail-able minus 1. (N-l). Rollalong switch must be configured for K-~N inputs and K
outputs.
GL(+) Ground location numbers along the seisrnic line increasing numerically in the direction in which the active qeophone array is advanced for each successive record sequence GL(-) Ground locations numbers decresing numeric-ally in the direction in which the active spread is advanced.
CH(+) Seismic data channel increasing (1 -to K) numerically along the active spread in the direction in which the active spread is advanced.
CH(-) Seismic data channels numerically decreasing (from K to 1) in the direction in which the active spread is advanced.

0l -18-rlote that the signs (~ ) of each of the ground location numbers (GL) signifies its relationship 05 with respect to the direction of the array advance; thel reference sensor ancl the sign of the channel nwnber are also dependent on the array reference status. t~ the latter is l, the CII is positive. [f not, then the sign is negative.
SEQUENCE START_EQUA'rION SET II
~ith the ground location numbers increasing but the channel numbers decreasiny, the following set oE equa-tions is used:

(l) RLSP = 'I'R-REF-GPNO+l (2) END 1 = REF+GPNO~K-]
(3) ENn 2 = REF
If GPNO = 0 (4) GAP l = 0 (5) GAP 2 = 0 If GPNO > 0 (4) GAP 1 = END l-GPLOC-l (5) GAP 2 = END l-GPLOC-GPNO
(6) ROOM = TR-REF-GPNO.
SEQUENCE START EQUATION SET III
.. . .
With ground location numbers decreasing but the channel numbers increasing, the following set of equations is used:

(l) RLSP = TR-~NP-REE`
(2) END 1 = REF
(3) END 2 = REF-(K-l)-GPNO
If GPNO = 0 (4) GAP l = 0 (5) GAP 2 = 0 If PPNO > 0 (4) GAP l = REF-GPOC-l (5) GAP 2 = REF-GPLOC-GPNO
(6) ROOM = REF-TR-GPNO+l 3~

SEQ_INGE s-TA~T-EQuAlrIoN SEr_IV
With both ground location nurnbers and channel 05 numbers decreasing, the followiny set of equations is used:

(1) RLSP = REF~'t'R-GPNO~l (2) END 1 - REI;`-(K~ GPNO
(3) END 2 = ~EF
If GPNO = 0 (4) GAP 1 = 0 (5) G~P 2 -- 0 If GPNO > 0 (4) GAP 1 = END l+GPLOC-l (5) GAP 2 -- END l~GPLOC~GPNO
(6) ROOM = REF-TR-GPNO

~ollowing these operations, the operator peruses the data at displays 27 and the encoders 26. If it is correct, he activates the trigger switch 61 (FIG. 4) to ultimately cause the energy source 16 (FIG. 1) to be activated. But before that can run, there is transference of all pertinent header data to the digital field recorder 21 in the manner of FIGS. 3 and 10. Note in FIG.
10, that after the operator activates the firing switch 61, the DFS 10 generates a series of commands to the recorder 21 which executes them in the manner shown.
I.e., the tape drive of the recorder 21 first accelerates the tape past the recording head until nominal operating speed is achieved. Then, regular header data is recorded on the tape at time Tl-T2. Note at time T2, the data associated with selected encoders 26 and displays 27 are next transferred in the manner depicted in FIG. 8 in which I/O array 34 enables the above "selected" elements to pass the associated data. That is to say, array 34 is capable of enabling displays 70-73 and encoders 48-53 so that data can be transferred via bus 80 and header interface 81 to the recorder 21. Address multiplexer 78 is used to ~0 generate the prerequisi-te format in conventional fashion. As a result, annotatlon of spread and source position associated with subsequently collected seismic 05 data, is assured. (Note from FIG. 9E that the controller 20 ls placed in an inhibited mode of operation durinq the recording of header data. Thus, if there are inadvertent chanyes in the controller status during the recordiny thereof, they do not affect operations.) It should be noted tha-t the address multiplexer

7~ preferably formats the data using standard guidelines adopted by the SEG Technical Standards Subcommittee on Tape E'ormats, in the manner of FIG. 7.

As shown in FIG. 7, header segment 79 has 2x2 array dimensions that are sixty-four (64) bytes by nine (9) characters wide. Organization of each byte include two 4-bit BCD segments utilized to indicate: line direction, group interval, shot depth, shot offset, offset direction, charge size, shot location, shot number, truck location, end group location, gap groups locations and associated data channel, in the order shown. As a result, adequate documentation of spread and source locations for annotation purposes, is assured.
~5 It should be understood that the invention is not only directed to the specific embodiments set forth above, but that many variations are readily apparent to those skilled in the art, so thus the invention is to be given the broadest possible interpretation within the terms of the following claims.

Claims (19)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Method of calculation storing and recording positional data associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey, said positional data being generated as bits of digital data stored in a microcom-puter system including a microprocessor unit (MPU), memory units, and a series of display/storage and switching devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in exploration activities are reduced, and annotation of exploration activities is automatically added, comprising (a) establishing in digital format via said micro-computer system, array geometry and exploration parameters that allow annotation in sequence of exploration activi-ties along said line, (b) automatically displaying at said display/storage and switching devices of said system, at least a portion of data of (a) in alpha numeric form for operator examina-tion and correction, if required, and (c) automatically recording said portion of data of (a) as header data so as to provide full annotation of exploration activities whereby errors in such exploration activities can be discovered and accounted for.

2. Method of Claim 1 in which (c) includes apply-ing clocking and trigger signals to said display/storage and switching devices whereby stored data is systematic-ally accessed and recorded as header data.

3. Method of Claim 1 in which step (c) is ini-tiated by activating a firing sequencing switch whereby a recorder unit of said DFS is energized and after its generation is stabilized, said header data is recorded to provide annotation of said activities.

4. Method of Claim 3 in which said activation of said firing switch also provides for subsequent activation of a seismic source of said source-detector array whereby generated waves propagate through an earth formation beneath said source-detector array and after detections by detectors of said array, are also recorded by said recording unit of said DFS.

5. Method of Claim 2 in which said recorder unit arranges said data in a convenient format including recording information associated with truck position along said line, reference location of said array, shot location along said line, gap position along said line, gap number, rollalong number, shot occurrence count, end position of said array, and channel recorder count.

6. Method of calculating, storing and recording positional data associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, said posi-tional data being generated as bits of digital data in a microcomputer system including a microprocessor unit (MPU), memory units and a series of display-storage and switching devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in exploration activity--both pre-activation and past-release of energy from said source-- are substan-tially reduced, comprising (a) encoding and automatically storing additional digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line, (b) automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, (c) automatically generating via said microprocessor system further additional data related to array parameters based in part on data encoded at (a), and previously stored data related to exploration parameters, (d) displaying at said display/storage and switching devices of said microcomputer system at least a portion of said new array parameters of (c) for operator examination and correction, if required, and (e) automatically recording portions of said displayed data of steps (b) and/or (d) as header data so as to provide full annotation of exploration activities whereby errors in such activities can be pinpointed and taken into account.

7. Method of Claim 6 in which step (c) is ini-tiated by activating a firing sequencing switch whereby a recorder unit of said DFS is energized and after its operation is stabilized, said header data is recorded to provide annotation of said activities.

8. Method of Claim 7 in which said activation of said firing switch also provides for subsequent activation of a seismic source of said source-detector array whereby generated waves propagate through an earth formation beneath said source-detector array and after detection of said array, are also recorded by said recorder unit of said DFS.

9. A ground position controller for manipulating calculating, storing, displaying and causing recordation of positional data, associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source -- are substan-tially reduced, said positional data being generated as bits of digital data using a microcomputer system com-prising a microprocessor unit (MPU), memory units, and a series of display/storage and switching devices inter-connected to each other and to a digital field system (DFS) via a system bus, said display/storage and switching devices including separate encoding means for automatic-ally encoding digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line of survey, separate display means for automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, before activation of said source, and separate switch sequencing means, connected to said microcomputer system and to said DFS for initiating, on command, an operational signal leading (i) to the recording of portions of said encoded and displayed data unto magnetic tape at a recorder unit of DFS, and subsequently (ii) to activation of a seismic source of said array, said displayed data at said separate display means being automatically generated via said microcomputer system using data related to array parameters based in part on encoded data, previously stored data related to exploration parameters, and newly generated array parameters whereby errors in exploration activities can be substantially reduced; said recorded data being associated with source and array positions vis-a-vis said known geographical positions along said line of survey.

10. Controller of Claim 9, with the addition of synchronization linkage means connected via said system bus, to said separate switch sequencing means of said series of display/storage and switching devices, whereby assuming that the displayed data at said separate display means meet with operator approval, a firing command is generated for transmission to said DFS whereby said por-tions of encoded and displayed data can be recorded a header data at said recorder unit of said DFS.

11. Controller of Claim 9 in which an end-of-record signal is generated by said DFS for said MPU after recordation at said recording unit of said reflected waves, has been completed, whereby said MPU recalculates next-in-line array and source positional parameters for operator approval and causes said parameters to be dis-played for operator examination at said separate display means.

12. Method of calculating, storing and displaying positional data, associated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, said posi-tional data being generated as bits of digital data in a microcomputer system including a microprocessor unit (MPU), memory units and a series of display/storage devices interconnected to each other and to a digital field system (DFS) via a system bus, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source -- are substantially reduced, comprising:
(a) encoding and automatically storing additional digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line, (b) automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, (c) automatically generating via said microcomputer system further additional data related to array parameters based in part on data encoded at (a), and previously stored data related to exploration parameters, and (d) displaying at said display/storage devices of said microcomputer system at least a portion of said new array parameters of (c) for operator examination and correction, if required, whereby errors in exploration activities can be substantially reduced, prior to activa-tion of said source of said array.

13. Method of Claim 12 in which (a) includes encoding as bits of digital data in said microcomputer system truck, source and array positions vis-a-vis said known geographical positions along said line of survey.

14. Method of Claim 12 with the additional steps of (i) assuming that the displayed data of steps (b) and (d) meet with operator approval transmitting a firing command to said DFS whereby seismic waves are generated by said source and propagate through an earth formation and in which reflections of said generated waves are detected by said array of detectors, followed finally by recording indications of said received waves at a recording unit of said DFS, (ii) in response to a generated command signal, recalculating next-in-line array and source positional parameters for operator approval using said MPU of said microcomputer system, (iii) displaying said parameters of (ii) for operator examination.

15. Method of Claim 12 in which (b) includes alpha-numeric displays of said positional data at said diaplay/storage devices, so as to depict truck position along said line, reference location of said array, shot location along said line, gap position along said line, gap number and rollalong number.

16. A ground position controller for manipulating, calculating, storing and displaying positional data, asso-ciated with a digital exploration system during generation and collection of seismic data by a source-detector array positioned at known locations along a line of survey at the earth's surface, whereby errors in exploration activity -- both pre-activation and past-release of energy from said source -- are substantially reduced, said positional data being generated as bits of digital data comprising a microcomputer system including a micro-processor unit (MPU), memory units and a series of display/storage devices interconnected to each other and to a digital field system (DFS) via a system bus, said display and storage devices including separate encoding means for automatically encoding digital data related to array geometry and exploration parameters that allow repetition in sequence of activities along said line of survey, and separate display means for automatically displaying at least a portion of said encoded data in alpha-numeric form for operator examination and for correction, if required, said displayed data at said separate means being automatically generated via said microcomputer system using data related to array parameters based in part on encoded data, previously stored data related to exploration parameters, and newly generated array parameters whereby errors in exploration activities can be substantially reduced.

17. Controller of Claim 16 in which said separate encoding means includes sub-encoding elements for encoding as bits of digital data truck, source and array positions vis-a-vis said know geographical positions along said line of survey.

18. Controller of Claim 16 with the addition of synchronization linkage means connected to said system bus, whereby assuming that the displayed data at said separate display means meet with operator approval, a firing command is generated for transmission to said DFS
whereby seismic waves are generated by said source and propagate through an earth formation and reflections of said generated waves, are detected by said array of detectors, followed finally by recording indications of said received waves at a recording unit of said DFS.

19. Controller of Claim 18 in which said DFS
generates a command signal for said MPU after said received waves have been recorded at said recording unit whereby said MPU recalculates next-in-line array and source positional parameters for operator approval and causes said parameters to be displayed for operator examination at said separate display means.