CA1258516A

CA1258516A - Adaptive seismometer group recorder having enhanced operating capabilities

Info

Publication number: CA1258516A
Application number: CA000523092A
Authority: CA
Inventors: Henry J. Mckinley, Jr.; Michael S. Mcnatt; Ralph E. Warmack; Sampat M. Rampuria
Original assignee: BP Corp North America Inc
Current assignee: BP Corp North America Inc
Priority date: 1985-12-03
Filing date: 1986-11-17
Publication date: 1989-08-15
Also published as: US4725992A; EP0226366B1; DE3679790D1; EP0226366A3; JPS62162987A; EP0226366A2; EG17769A

Abstract

ABSTRACT OF THE INVENTION
In a seismic exploration system, an adaptive seismometer group recorder having enhanced operating capa-bilities for acquiring, processing, and storing seismic signals is provided. The adaptive seismometer group recorder includes a solid state memory, a microprocessor and input means for electronically downloading operating programs into the solid state memory whereby menus of recorder operating parameter are provided by the operating programs to the microprocessor to electronically recon-figure the SGR for various geological settings. The microprocessor is responsive to coded signals for selecting sets of recorder operating parameters from the menu of recorder operating parameters provided by the operating programs. The electronically downloaded menus of recorder operating parameters digitally reconfigure the operating characteristics of the seismometer group recorder without necessitating the implementation of hard wired circuitry changes.

Description

31~
8567, et al.
McNatt, et al.

ADAPTIVE SEISMOMETER GROUP RECORD~R ~AVING
_ .
ENHANCED OPERATING CAPABILITIES
BACKGROUND OF THE INVENTION

This invention relates generally to geophysical exploration. More particularly, this invention is 15 directed to a seismic exploration system including an adaptive seismometer group recorder having enhanced oper-ating capabilities for acquiring, processing, and storing seismic signals.
Seismic exploration involves generating seismic 20 waves at the surface of the earth by means of a seismic source. The seismic waves travel downwardly into the earth and are reflected and~or refracted due to differ-ences in the elastic impedance at the interface of various subterranean formations. Detectors, called seismometers, 25 or geophones, located along the surface of the earth, and/or in a borehole produce analog electric seismic sig-nals in response to detected seismic wave reflections and/or refractions. The analog electric seismic signals from the seismometers, or geophones, can then be recorded.
30 Alternatively, the analog electric seismic signals from the seismometers, or geophones, can be sampled and digi-tized prior to being recorded. The seismic data recorded in either manner are subsequently processed and analyzed to determine the nature and structure of the subterranean 35 formations.
Various portable seismic exploration systems are known. One type of portable seismic exploration system employs cableless seismic recording systems developed for seismic prospecting by digitally recording seismic signals produced by seismometers or geophones without the need for multiconductor cables o~ alternate means such as ~adio or wire telemetry for transmitting seismic data to a central 5 recording poin~. In particular, the cableless seismic recording system includes recorders placed near the seis-mometer, or geo~hone, locations and arranged for producing individual recordings in response to control signals transmitted ~rom a control point over a communication 10 point, preferably a radio communication link. A second type of portable seismic exploration system employes var-ious telemetry systems, which merely relay the acquired seismic data by way of a radio communications link,or a fiber optic or electric cable, to a central recording 15 location.
The forerunner of cableless seismic recordinq system disclosed by Montgomery United States Patent 3,283,295 comprises a cableless seismic analog recording system wherein a radio receiver is associated 20 with a recorder located at each seismometer, or geophone, location in the prospect area. The recorder is activated by control signals from a centrally located radio trans-mitter and thereafter records the analog seismic data.
However, the cableless seismic analog recording system 25 disclosed in Montgomery is limited to an analog recording of a seismic signal as a frequency modulated magnetic record which is inferior to digital recording, which has unexcelled accuracy, dynamic range, and freedom from noise interference. Additionally, Montgomery discloses that all 30 remotely operated recorders are in operation for each recording. Reconfiguration of the array for each new recording involves repositioning the various recorders along the line of survey.
Broding, et al., U.S. Patent 3,806,864, hereby 35 incorporated by reference into this specification to form a part thereof, discloses a cableless seismic recording system which overcomes the two noted deficiencies of the cableless seismic analog recording system disclosed by ~S8516 Montgomery in that the recording produced is digital in format and out of a large array of recorders remotely deployed in one prospect area, only those recorders needed for producing a given set of recordings are selectably 5 activated and caused to record seismic data. The remaining recorders remain essentially quiescent until there is a desire to produce a set of recordings for the prospect areas where they are situated. As disclosed in Broding, the seismic data are recorded on a magnetic tape 10 cartridge. The recorded seismic data are filtered, ampli-fied and digitized in accordance with a fixed menu pro-vided by hard-wired circuitry of the recorder.
Many techniques for generating seismic waves are currently in use. An exploding dynamite charge is an 15 example of a high energy seismic source which generates a sharp pulse of seismic energy. Vibrators, which generate a "chirp" signal of seismic energy and hammers are exam-ples of low energy surface seismic sources. In the case of vibrators, the recorded seismic wave reflections and/or 20 refractions are cross-correlated with a replica (called the pilot signal) of the original chirp signal in order to produce recordings similar to those which would have been produced with a high energy seismic source. This process is commonly referred to by its tradename, VIBROSEIS*
Unfortunately, the recorded seismic data always include some background noise in addition to the detected seismic waves reflected and/or refracted from the subsur-face formation (referred to as a seismic signal). The ambient noise appears in many forms, such as atmospheric 30 electromagnetic disturbances, wind, motor vehicle traffic in the vicinity of the prospect area, recorder electrical noise, etc. When a high energy seismic source is used, such as dynamite, the level of detected seismic signal is usually much greater than ambient noise.
The use of the cableless seismic recording system disclosed by Broding, et al., is most advantageous in instances when seismic data is generated by a high energy seismic source. However, when a low energy surface * a trademark seismic source is used, such as a vibrator ~sed in Vibroseis type seismic prospecting, the ambient noise can be at a level greater than the seismic signal. For that reason, Vibroseis-type seismic records are often produced 5 from the repeated initiation of the low energy surface seismic source at about the same oriyination point, thereby producing a sequence of seismic data based on the seismic wave reflections and/or refractions that have traveled over essentially the same path and, therefore, 10 have approximately the same travel times. Because the data storage capacity in commercially available, magnetic tape cartridges such as disclosed by Broding, et al., is limited, the capacity is not always adequate for recording every repetition individually, or accommodating the 15 increased record length required when the low energy seismic source is used.
In order to lessen the impact of the limited data storage capacity of commercially available magnetic tape cartridges, seismic data generated by low energy 20 seismic sources can be vertically stacked (summed or com-posited) prior to recording in order to economize tape usage. Weinstein, et al., U.S. Patent 3,946,357 and Broding, U.S. Patent 4,017,833 both disclose hard-wired digital circuitry in the recorder of a cableless seismic 25 recording system for summing seismic data acquired by the recorder in accordance with a fixed menu.
Weinstein, et al., U.S. Patent 3,946,357, dis-cusses a recorder including an adder circuit which sums newly acquired seismic-trace data received from a shift 30 register with previously accumulated seismic-trace data temporarily stored in random access memory between conse-cutive initiations of the seismic source, and the accumu-lated sum is later recorded on a magnetic tape cartridge.
Broding U.S. Patent 4,017,833 discloses a recorder 35 including a plurality of recirculating dynamic shift registers connected in cascade for storing the accumulated sum between consecutive initiations of the seismic source in order to economize power consumption.

~5~

In spite o~ such developments, a need remains in the field of geophysical exploration for acquirinq, pro-cessing and storing seismic data with a portable seismom-eter group recorder having means for electronically down-5 loading operating programs providing a plurality of menusof recorder operating parameters into the portable seis-mometer group recorder. Electronically downloading oper-ating programs into the seismometer group recorder pro-vides an operator with a plurality of menus of recor~er 10 operating parameters to remotely select from such that the portable seismometer group recorder can be remotely, elec-tronically reconfigured to acquire and process seismic data for various geological settings without the necessity or expense of making hard-wired modifications to or 15 replacements of the circuitry of such portable seismometer group recorders. Additionally, a need exists to provide the portable seismometer group recorder with means respon-sive to coded signals, transmitted from a remote control unit, for selecting recorder operating parameters from a 20 menu of recording operating parameters to electronically reconfigure the portable seismometer group recorder to process the acquired seismic data for different geological settings without having to physically retrieve the por-table seismometer group recorder. The present invention 25 comprises an adaptive seismometer group recorder and method of geophysical exploration directed to fulfilling such needs.
SUMMARY OF THE INVENTION
In a seismic exploration system, an adaptive 30 seismometer group recorder (SGR) having enhanced operating capabilities for acquiring, processing and storing seismic signals is provided. The adaptive SGR of the present invention includes a solid state memory and input means for electronically downloading a plurality of operating 35 programs, which provide menus of recorder operating param-eters, into the solid state memory of the SGR. The adap-tive SGR also includes processing means responsive to coded signals for selecting sets of recorder operating ~5~5~

parameters, to acq~lire, process and store seismic signals for different geological settings, from the menus of recorder operatinq parameters provided by the operating programs resident in the solid state memory. With the 5 electronically downloaded Gperating programs, the SGR can be electronically reconfigured by the processing means in response to transmit~ed coded signals Lrom a remote point to acquire, process and store seismic data ~or a plurality of different geological settings, as well as test the 10 seismometer group recorder and geophones attached thereto.
In a preferred embodiment of the present inven-tion, a high-speed data transceiver is provided with the SGR for electronically downloading operating programs into the solid state memory of the SGR. The solid state memory 15 of the SGR is electronically programmable, and can be either volatile or nonvolatile solid state memory. The operating programs electronically downloaded into the solid state memory can provide menus of recorder operating parameters for acquiring and processing seismic data for 20 different geological settings such as: a plurality of seismic signal low-cut filtering frequencies; a plurality of seismic signal sampling rates; a plurality of weighting and stacking algorithms; a plurality of seismic signal gain settings; an option for inserting a temperature com-25 pensated notch filter or an automatic notch filter; aswell as a plurality of SGR diagnostic instructions.
The SGR also includes a microprocessor respon-sive to coded signals transmitted from a remote point for selecting sets of recorder operating parameters from the 30 menus of recorder operating parameters provided by the operating programs so as to electronically reconfigure the SGR for a plurality of different geological settings without the need to either physically retrieve the the SGR
and/or effect hard-wired changes thereto. The ability to 35 electronically download additional menus of recorder oper-ating parameters to electronically reconfigure the SGR for different geological settings is highly desirable. Wein-stein, et al., and Broding both provide a single, fixed menu of recorder operating parameters resident in either read only memory or hard-wired digital logic circuits and changes thereto require modifying the existing hard-wired digital circuitry or the addition of separate components 5 connectable t~ the existing hard-wired digital circuitry of the SGR. Unlike known portable SG~ units, the adap~ive SGR of the present invention provides enhanced operating capabilities ~ithout having to physically alter onboard circuits to reconfigure its recorder operating parameters 10 or to physically retrieve the SGR units.
The electronically programmable solid state memory includes a magnetic bubble memory subsystem or a high capacity, battery backed-up CMOS DRAM which are employed to electronically store both acquired sei~mic 15 data as well as menus of recorder operating parameters provided by the operating programs. The use of magnetic bubble memory or CMOS DRAM components in the solid state memory system is highly desirable because of their nonvo-latile character or their ability to affect nonvolatile 20 characteristics respectively and their resistance to envi-ronmental stresses such as extreme temperatures, humidity, shock and vibration. The nonvolatile character of the magnetic bubble memory components also provides a method for regulating the generally high power consumption 25 requirements of the magnetic bubble memory subsystem so as to conserve the energy capacity of the SGR power supply.
The use of magnetic bubble memory components with limited power capacity systems, such as the portable SGR of the present invention, would generally have been precluded but 30 for limiting the magnetic bubble memory components energy consumption. By activating the magnetic bubble memory subsystem only when predetermined quantities of seismic data are available for transfer from a volatile random access buffer memory to the bubble memory system or to 35 electronically download additional operating programs, the energy consumption of the magnetic bubble memory subsystem can be limited. Alternatively, high capacity, battery backed-up CMOS DRAM can be employed since it consumes very little power to affect nonvolatile characteristics.

~5~35~6 The use of a so]id state memory subsystem Eor the storage oE seismic data generally eliminates the need for moving parts associated with magnetic tape cartrid~e recording systems of the type employed by other c~bleless 5 seismic recorders and thus enhances the adaptive SGR's reliability. Unlike previous portable seismic recorders empioying magnetic tape cartridges, the need to physically remove the magnetic tape cartridge for transcription and further processing of the seismic data can be eliminated.
10 As such, the adaptive SGR can now be packaged in a sealed container to protect its various electronic components from the generally harsh operating environments.
Further, the various operating programs resident in the magnetic bubble memory subsystem or CMOS DRAM solid 15 state memor~ can be electronically transferred into low power consumption, volatile, solid state operating memory which can be employed by the microprocessor to electroni-cally reconfigure the adaptive SGR. Other advantages of the adaptive SGR of the present invention will be evident 20 from the figures and the description of a preferred embod-iment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a diagrammatic layout of the seismic exploration system including adaptive SGR;
FIGURE 2 is a partial schematic and partial block diagram of the electrical components of a preferred embodiment of the adaptive SGR of the present invention;
FIGURE 3 is a partial schematic and partial block diagram of the electrical components of a preferred 30 embodiment of the adaptive SGR;
FIGURE 4 is a partial schematic of partial block diagram of the electrical component of a preferred embodi-ment of the adaptive seismometer group recorder.
DESCRIPTION OF A PREFERRED EMBODIMENT
In accordance with the present invention, an adaptive SGR having enhanced operating capabilities for acquiring, processing, and storing seismic data is pro-vided in a seismic exploration system. The seismic explo-1~51~G
g ration system includes a plurality of portable adaptive SGR's spaced about a prospect area in predeter~ined loca-tions each having at least one string of seismometers or geophones connected thereto for ac~uiring seismic data.
5 Each adaptive SGR is responsive to coded signals trans-mitted from a remote control unit for remotely, electroni-cally reconfisuring the recorder operating parameters of the SGR to acquire, process and store seismic data for different geological settings.
Prior to deploying the adaptive SGR's of the present invention in the field, operating programs pro-viding menus of recorder operating parameters for the adaptive SGR are electronically downloaded into each adap-tive SGR such that coded signals transmitted from a remote 15 control unit and acted upon by the adaptive SGR can be employed to electronically reconfigure the adaptive SGR to acquire, process and store seismic data for various geo-logical settings. Additionally, each SGR is programmed to respond initially only to coded signals which include its 20 unique individual serial identification code. Initially, after the adaptive SGR's are deployed, a first coded signal, labeled a program call, is transmitted by the remote control unit to each adaptive SGR to assign recorder header data including a field location identifier 25 and to select an initial set of recorder operating parame-ters from a menu of recorder operating parameters provided by the operating programs resident each adaptive SGR. A
variation of the program call, labeled a program change call, can be made between acquisition cycles to affect 30 changes in the seismic data acquisition and processing parameters without having to physically retrieve the adap-tive SGR so as to modify or replace its electronic cir-cuitry. A second coded signal, labeled a test call, is then transmitted to each adaptive SGR to verify the field 35 location identifier assignment as well as to initiate a series of self-diagnostic tests to verify the function-ality of each adaptive SGR. The sequence of program call and test call is then repeated for all other adaptive SGR's in the seismic exploration system.

:~S~5~6 With the adaptive SGR's programmed and tested, a third series o~ coded signals, labeLed acquisition calls, are transmitted to selectably activate predetermined adap-tive SGR's to collect seismic data. The acquisition call 5 includes a zero-time mark for the simultaneous initiation of seismic data collection by each adaptive seismic recorder in operation. The activated adapti~ie SGR auto-matically deactivates after a prescribed time period. The acquisition call can also initiate the Eiring of a 10 dynamite charge or the synchronized starting of vibrators.
The seismic data acquired and processed, in real time by each adaptive SGR, are initially stored in a volatile buffer memory and after a predetermined amount of seismic data has been so collected, the processed seismic data are 15 electronically transferred to a solid state memory, pref erably magnetic bubble memory subsystem. Alternatively~
high capacity, battery backed-up CMOS DRAM can be employed since it consumes very little power to affect nonvolatile characteristics. The various coded signals received by 20 the adaptive SGR will be more fully discussed below.
Typically, after a day's worth of seismic explo-ration, the adaptive SGR's are gathered up and returned to a battery charging/seismic data transcriber truck. Here, employing the adaptive SGR's high speed data transceiver 25 or link in conjunction with the solid state memory, the seismic data stored therein can be electronically trans-ferred from the adaptive SGR to the transcriber truck for transcription into a format suitable for further pro-cessing by a large central processing unit. The solid 30 state memory, which in the preferred embodiment includes magnetic bubble memory subsystem, has a capacity approxi-mating a typical days' worth of vibroseis-type seismic data. Since the seismic data are stored in solid state memory, the adaptive SGR electrical components can be 35 housed in a sealed container to insulate them from harsh operating environments. Additionally, the high speed data transceiver or link can be employed to electronically download new operating programs providing new menus of ,C~8~
--ll--recorder operating para~eters into the magnetic bubble memory subsystem without having to open the adaptive SGR
container to replace or modify existing hard-wired elec-tronic circuitry to affect changes in the operating char-5 acteristics of the adaptive SGR.
A detachable connector cable couples the high speed data transceiver of the adaptive SGR to the tran-scriber truc~ to permit the comm-lnication of operating programs to the adaptive SGR and the communication of 10 seismic data to the transcriber truck. A separate deta-chable cable couples a power supply of the adaptive SGR to a battery charging system of the charging/transcriber truck to recharge the power supply. The menus of recorder operating parameters provided by the operating programs 15 resident in the solid state memory system can be trans-ferred to a microprocessor operating memory of the SGR
each time the adaptive SGR is activated or if the oper-ating programs within the operating memory are determined to be in error by the microprocessor.
Referring now to Figure 1, a seismic exploration system is shown diagrammatically. Operationally, the adaptive SGR of the present invention has enhanced oper-ating characteristics for acquiring, processing, and storing seismic data not previously provided. Specifi-25 cally, the adaptive SGR of the present invention can be remotely programmed to electronically reconfigure its recorder operating parameters without electronic circuitry modifications or additions. The operating capabilities of the adaptive SGR can also be altered by electronically 30 downloading a plurality of operating programs providing new menus of recorder operating parameters wi.thout employing electronic circuitry modifications or additions thereto.
As seen in Figure 1, a plurality of adaptive 35 SGR's (401-416) are deployed a prospect area at spaced locations. Each of the adaptive SGR's (401-416) has at least one string of geophones G connected thereto. Each adaptive SGR (401-416) has a unique individual serial 1~.385~i identification code to which it is responsive when the individual serial identification code is transmitted over a radio frequency IRF) communications link at a prese-lected frequency f1. An appropriate control means is 5 needed for controlling seismic prospecting utilizing a preferred embodiment of the adaptive SGR of the present invention. The tunction of such con~rol means is to transmit coded signals at preselected radio frequencies.
In particular, a remote control unit K is provided to 10 transmit a program call, including the unique individual serial identification code at the selected frequency f1, so as to initially activate and program each adaptive SGR
(401-416). The unique individual serial identification code is initially set by installing jumper wires within 15 the circuitry of the SGR. A microprocessor within the SGR
reads the jumper wire connections and stores this as the individual serial identification code in an operating memory to compare the individual serial identification codes transmitted by the control unit K.
Since the field locations of SGRs within the prospect areas is a matter of importance for subsequent processing of the seismic data collected by each adaptive SGR seismic recorder (401-416), a coordinate system of station and line numbers is typically employed in seismic 25 exploration. As shown in Figure 1, each adaptive SGR can be initially activated using its individual serial identi-fication code and thereafter assigned a station and line field location code to which it will also respond. Each adaptive SGR (401-416) can have multiple strings of geo-30 phones G attached thereto. In one embodiment, each adap-tive SGR ~401-416) can have four separate input channels, each adapted to be connected to a separate string of geo-phones G. As such, each adaptive SGR can additionally be assigned a field location code for each channel, for 35 example, adaptive SGR serial identification code 401 with four separate input channels will have the following field location codes: A:l:l, A:1:2, A:1:3, and A:1:4 (line number:station number:channel number). While adaptive SGR

l~S85~

serial identification code 406 would have the following field location codes: C:2:1, C:2:2, C:2:3, and C:2:4, etc. Thereafter each adaptive SGR (401-416) will respond either to its individual serial identification code or its 5 field location code. The twofold identification code technique permits the operator to remotely call up an adaptive SGR either by its field location code and/or its individual serial identification code with the remote con-trol unit K. During the course of seismic exploration, it 10 is common practice to relocate each adaptive SGR several - times in particularly large prospect areas and as such, each adaptive SGR must be capable of being assigned new field location codes.
Now looking to Figure 2, a partial schematic and 15 partial block diagram of the electrical components of adaptive SGR R are shown to the right of the dashed line.
The flow paths for seismic data, command and control sig-nals, and electronically downloading additional operating programs with reference to the electrical components of 20 the adaptive SGR R will be more fully discussed below.
The adaptive SGR R includes a communications link ~0. In a preferred embodiment the communication link 10 can be a RF receiver using a Manchester II encoding scheme operating between 153 and 159 MHz in 5KHz steps.
25 The communication link 10 is adapted to receive coded sig-nals transmitted from the remote control unit K of Figure 1 for selecting acquisition and operating parame-ters from a menu of recorder operating parameters provided by operating programs and for initiating various diagnos-30 tics within the adaptive SGR. Coded signals received bythe communications link 10 are communicated to and evalu-ated by a central processing unit 20 (CPU). The central processing unit 20 can be a microprocessor such as an NSC 800 manufactured by National Semiconductor. An oper-35 ating memory 30 provides a residence for various operatingsoftware which the CPU 20 employs to evaluate the coded signals from the communications link 10 and to generate command and control signals to various electrical compo-~58~6 nents of the adaptive SGR R. The operating memory 30 canbe of the random access memory (RAM) type. Since the operating memory 30 is RAM, it can easily be reprogrammed for new operating software or programs electronically 5 downloaded into the adaptive SGR R, as shall be discussed below.
In response to coded signals frcm the control unit K, the CPU 20 can issue various command and control signals to the communications link lO, a data acquisition lO subsystem 40, an arithmetic processing unit 50, a buffer memory 60, a solid state magnetic bubble memory 70, a power supply 80 and a high speed data link or tran-sceiver 90, all of which will be more fully discussed below.
In a preferred embodiment, the adaptive SGR R
includes two input channels for the input of analog sig-nals from two strings of geophones G. In particular, the geophone input is received by the data acquisition sub-system 40. As shall be discussed more fully below, the 20 data acquisition subsystem (DAS) 40, in response to com-mand and control signals from the CPU 20, selectably amplifies, filters and digitizes the input analog signal of the geophones G.
The amplified, filtered and digitized output 25 signals ~hereinafter seismic data) of the DAS 40 can be transmitted either to arithmetic processing unit (APU) 50 or directly to buffer memory 60. If the SGR R is employed with high energy seismic sources, such as dynamite, a por-tion of the coded signal transmitted from the remote con-30 trol unit K directs the CPU 20 to issue a command and con-trol signal to selector switch 45 which directs the seismic data to the buffer memory 60. In the case of low energy seismic sources, such as swept frequency vibrators, the seismic data are first directed to APU 50 to be selec-35 tably weighted and vertically stacked on a real time basisas the seismic data are collected and thence to buf,er memory 60. The APU 50 selectably weights and vertically stacks the seismic data in response to coded command and 5 ~ 6 control siqnals from the CP~ 20. sy way of example such weighting and stacking can be that set forth in United States Patent Numbers 4,561,074 and 4,561,075, both assigned to Amoco Corporation. Both weighting schemes 5 have also been implemented in a seismometer group recorder as described in United States Patent Number 4,561,075, assigned to Amoco Corporation.
The weighted and vertically stacked seismic data from the APU 50 or the seismic data from the high energy 10 source are temporarily stored in the buffer memory 60.
Buffer memory 60 can be electronically programmable dynamic RAM-type memory having 256 Kbyte storage capacity.
After a predetermined amount of seismic data are collected and stored in the buffer memory 60, as monitored by the 15 CPU 20, the CPU 20 activates the solid state magnetic bubble memory subsystem ~BMS3 70 and electronically trans-fers the collected seismic data contained within the buffer memory 60 to the BMS 70. After completion of such transfer the CPU 20 deactivates the BMS 70. The BMS 70 is 20 preferably nonvolatile, electronically programmable solid state memory and can include Fijitsu or Hitachi 4 Mbyte magnetic bubble memory components. Alternatively, high-capacity, battery backed-up CMOS DRAM can be employed because it can affect nonvolatile characteristics with 25 very low power consumption. In the preferred embodiment, the BMS 70 has a total storage capacity of 8 Mbyte or 4 Mbyte per input channel; however, this storage capacity can easily be increased by the addition of more magnetic bubble memory components. The ~MS 70 is also residence 30 for all operating software or programs to be implemented in the adaptive SGR R, including: weighting and vertical stacking algorithms for use in the APU 50 and operating software and programs for the operating memory 30 as well as diagnostic instructions and general recorder operating 35 sequencesO

lL ~5~5~6 The adaptive SGR R al50 includes a high-speed data transceiver or li~k (HSDL~ 90 which is responsive to command and control signals from the CPU 20 for electroni-cally transferring seismic data stored in the BMS 70 to a 3 remote transcriber 100 through a detacha~le cable 35, which transcribes the seismic data into a format, such as magnetic tape reels 110, suitable for further processing by a mainframe computer. The HSDL 90 also 2rovides a com-munications path for electronically downloading additional 10 operating programs, having new menus of recorder operating parameters, in the BMS 70. In the preferred embodiment, HSDL 90 comprises a data link operating at a 2 Mbit/second burst rate for communicating data encoded with a Man-chester II encoding scheme. A high level data link con-15 trol protocol standard is then used and the operating pro-grams or seismic data, are communicated in messages of 1 Kbyte to 16 Kbytes in length.
The power supply 80 comprises a 12 volt system of rechargeable batteries such as D cell or C cell type.
20 Since rechargeable batteries are employed, the power supply 80 can easily be recharged daily at the time of transcription of seismic data at the charging/transcriber truck.
With reference now to Figure 3, a partial sche-25 matic and partial block diagram of the electrical compo-nents of the adaptive SGR R, the flow paths of the command and control signals, as well as the flow paths for elec-tronically downloaded operating programs are shown. In response to a coded signal transmitted from the remote 30 control unit K, the RF receiver 115 receives and communi-cates a command and control signal to the CPU 120. Con-trol of all subsystems within the adaptive SGR R origi-nates from the CPU 120. The operating software or programs residing in the CPU operating memory are executed 35 by the CPU 120, thereby controlling all other subsystems in the adaptive SGR R.
In response to either a program change call or a program call, from the remote control unit K, as detailed 1'~S8Sl~

in Table I, the CPU 120 directs command and control signals to the APU 140 which further evaluates such com-mand and control signals by using its own APU operating program to select from one of the inverse power weighting 5 (IPW) and stacking algorithms resident in memory of the APU 140 as fixed algorithms or algorithms electronically downloaded therein from the BMS 160. The CPU 120 also directs the APU 140 to select window lengths for pro-cessing the digitized sei~mic data from the DAS 180.
10 Information concerning the type of seismic source used is also conveyed in such calls whereby the selector switch ~5 of Figure 2 directs the flow of seismic data from the DAS 180.
In further response to program change calls and 15 program calls, the CPU 120 directs command and control signals to the DAS 180 whereby the sample interval or sam-pling rate for digitizing the analog signal from the geo-phone can be selected. The command and control signal from the CPU 120 to the DAS 180 can further activate a low 20 cut filter as well as select a low cut frequency for the low cut filter of the DAS 180. An automated notch filter (generally centered on 50 Hz or 60 Hz) can be activated in the DAS 180 in response to the command and control signal.
In particular, the automated notch filter is automatically 25 switched in or out if induced power line noise in the geo-phone input is above or below a preset threshold level.
The CPU 120 samples the input analog signal from the geo-phones on a preset schedule or in response to coded sig-nals from the remote control unit K. This is generally 30 done before commencing seismic data acquisition such that the input analog signal from the geophones largely repre-sents induced power line signal. The CPU 120 switches in the automatic notch filter and obtains a root mean square (RMS) value of the input analog signal. Then, the CPU 120 35 switches the automatic notch filter out and obtains a second RMS value of the input analog signal. The CPU 120 computes the difference between the two RMS values of the input analog signal and compares such difference to a ~ 5~516 stored value in operating memory. If the difference in RMS values is less than the stored value, the CPU 120 switches the automatic notch filter out of the DAS 180;
however, if the difference in RMS values is equal to or 5 greater t~.an the stored value, the CPU 120 switches the automatic notch filer in. Prea~plifier gain and e.~ternal gain for the gain-ranging amplifier of the DAS 180 can also be selected with command and control signals from the CPU 120. In the preferred embodiment, the automatic notch 10 filter comprises three separate notch filters in parallel, each adapted for optimum efficiency over a given range of temperatures. Hence, the CPU 120 selects the notch filter having a temperature range overlapping the ambient temper-ature.
The CPU 120 includes a clock which periodically, e.g., once every 3 secs or once every 30 secs, initiates a power up signal to the power supply 170 whereby the RF
receiver 115 can monitor for coded signals at the selected frequency which contain either the field location code or 20 the unique individual serial identification code of a par-ticular SGR. In response to a coded signal directed to a particular SGR, the CPU 120 directs command and control signals to the power supply 170 to activate the various other components and subsystems within the adaptive SGR.
25 Since the CPU 120 operating memory is volatile RAM type memory, upon activation the CPU 120 transfers selected operating programs within the BMS 160 to the CPU operating memory, as directed by the coded signals. Additionally, in response to program change calls and program calls, the 30 CPU 120 directs command and control signals to the BMS 160 whereby operating programs downloaded therein by way of the HSDL 210, can be transferred to the APU operating memory or the RF receiver decoder. New carrier frequen-cies from the remote control unit K, to which the RF
35 receiver 115 and the CPU 120 will respond, can be devel-oped from operating programs downloaded therein such that the RF receiver 115 will respond to coded signals of dif-ferent carrier frequencies from the remote control unit K.

This is particularly useful in ~reas where certain frequencies cannot be employed.
There are several different types of operating programs that can be electrically downloaded from the 5 transcriber 100, as shown in Figure 2, through the deta~
chable cable 95 to the ~SDL 210 in Figure 3 and include:
diagnostic programs, math weighting and stacki~g algorithm programs and operating system programs. All three types of operating 2rograms follow a similar path. They are 10 downloaded from the transcriber truck via the high-speed data transceiver 210 into the buffer memory of the CPU.
The operating program changes are then loaded from the CPU
buffer memory into the solid state magnetic bubble memory subsystem 160. Operating system programs resident in the 15 BMS 160 can be transferred to the CPU operating memory upon command of the CPU 120. The diagnostic programs resident in the BMS 160 can similarly be transferred to the CPU operating memory. Note that only one of these two types of programs can be loaded into the CPU operating 20 memory at any one time. Weighting and stacking algorithm program changes can be transferred to the APU memory from the BMS 160 upon command of the CPU 120.
Looking next to Figure 4, analog seismic signals generated by geophones are communicated to the data acqui-25 sition system~ DAS 300. The DAS 300 filters, amplifiesand diqitizes the analog signals in accordance with selected recorder operating parameters and stores the seismic data either in the buffer memory 320 directly, if the seismic data are of the dynamite type or alternately, 30 the seismic data are first routed to the APU 340 if they are of the vibrator type.
If the seismic data are of the type generated by dynamite, then one shot of dynamite will result in one signal record in the buffer memory 320. This record is 35 subsequently sent to the data storage area of the BMS 360 after a predetermined amount of seismic data have been collected, as determined by the CPU 120. In the case of Vibroseis-type seismic data, the output of the DAS 300 is S~35~6 ~20-first sent to the APU 340 and then to the buffer memory 320. The buffer memory 320 also serves as a stacking memory for additional seismic data to pass from the DAS 300 to the APU 340. The APU 340 then weights and 5 vertically stacks the seismic data from the buffer memory 320 in the form of an averaging process. As each successive set of Vibroseis-type data are input to the DAS 300, the APU 340 weights and vertically stacks each set into the buffer memory. At the end of a multiple 10 sweep process, the seismic data in the buffer memory 320 are then sent to the data storage section of the BMS 360.
During the day, seismic data input through the DAS 300 system to begin filling up the bubble memory subsystem.
At the end of the day, the seismic data are retrieved Erom i5 the BMS 360 over the HS~L 380, as shown in Figure 4.
Seismic data pass from the BMS 360 into the HSDL segment of the buffer memory and from the buffer memory 320 through the ~SDL 380 and a detachable cable into the tran-scriber, as shown in Figure 2. All of which is further 20 described in Canadian Patent Application Serial Number 461,035 assigned to Amoco Corporation.
OPERATION
All control of the SGR systems originates from the CPU or central processing unit. The central pro-25 cessing unit controls all activities of the data acquisi-tion subsystem, the radio frequency receiver, the power supply, the BMS, APU, and the hish-speed data transceiver.
The operating system program is stored in the CPU oper-ating memory and is executed by the CPU, thereby cont-30 rolling all other subsystems of the adaptive seismometergroup recorder.
Since there are several ways in which the CPU
operating memory may be altered or destroyed, including:
(l) contact with a high voltage electric fence, (2) nearby 35 lightening strikes or (3) nearby contact of high voltage cross-country wires, a portion of the operating memory also includes nonvolatile permanent memory, such as EPROM.

3;5~6 In this permanent memory, there exists a software program which periodically determines if any errors exist in the operating program resident in the operating memory. If any errors are detected, then a new version or a replace-5 ment version of that operating program is electronicallydownloaded from the bubble memory subsystem into the oper-ating memory by the CPU. The EPROM also contains its own check sum program to verify proper operation of the EPROM.
Si~ types of RF coded signals are received by l0 the adaptive SGR. The six coded signals include program call, short program call, program change call, acquisition call, reset call and test call.
The general sequence of these calls is as fol-lows:
l. Issue a Program Call to an individual SGR to a) assign line/station numbers to each recording channel and b) select acquisition parameters, or lssue a global program call to all SGR's simultane-ously omittir.g the line, station numbers,

2. Issue a Test Call to an individual SGR to verify the line/station number assignment and run internal diagnostic-tests or issues a continuous line/station and test call to each recorder in the line,

3. Repeat steps l) and 2) for all the SGR's set up for the day's data collection operations, and

4. Issue a series of Acquisition Calls to large groups of SGR's to collect seismic data.
CODED SIGNALS
The purpose of the Program Call, Short Program 30 Call and Program Change Call is to set up the SGR for data acquisition. Operating parameter information is entered into the control unit K, then transmitted to each SGR via the RF communications link. The various recorder oper-ating parameters to be selected and header data assigned 35 to each adapted SGR are shown in Table I below.
The Program Call is the primary acquisition par-ameter setup call used in day-to-day field operations. It is directed to a single SGR via its unique serial identi-~L~5~

fication code, and assigns a line/station number to each acquisition channel to be used. The Program Call can also be used to change the recorder acquisition parameters for large groups of SGR simultaneously. The Short Program

5 Call is used to reassign line~station numbers to a single SGR, without changing any of the recorder acquisition par-ameters previously assigned such as when the SGR is relo-cated. An overnight mode ma-y be commanded as part of a Program Call or a Program Change Call from the remote con-10 trol unit K. The overnight co~mand causes the SGR to gointo a very low-power mode whereby it powers up only once every 30 seconds to check for the presence of an RF call.
In normal operation, the SGR powers up once every 3 seconds instead of once every 30 seconds, hence saving 15 power. This enables SGR's which are in field operation to be "put to sleep" at the end of the day (or over lunch, etc.) and "awakened" the next morning. This, of course, assumes that sufficient battery capacity remains within the power supply for the extra day's operation.

TABLE I - PROGR~M CALL TYPES
_ _ _ _ _ _ . _ Short Program Program Change Program Call Call__ Call_ _ ___ ___ Content~
5 ~eader Data * No. of Call sequences * 1st Sequence - Start Line/
Station No.
* 1st Sequence - Stop Line/
Station No.
* 2nd Sequence * Last Sequence * * SGR serial no. (16 bit binary), up to 65,000 boxes * * No. channels (1, 2, 3 or 4) * * Record length - 3 digits, 99.9 seconds max.
Line/Station Parameters * * Ch 1 line no.
* * Ch 1 station no.
* * Ch 2 line no.
25 * * Ch 2 station no.
* * Ch 3 line no.
* * Ch 3 station no.
* * Ch 4 line no.
* * Ch 4 station no.
* * Date of Recording

6 digits; 2 digit year (e.g., 84) and 3 digit Julian day (e.g., 276), * * Set or clear overnight mode L'~S~5~t;

Short Program Program Change Program Call Call Call Contents DAS Modes .

* * Samp]e InterveLl (.5, 1, 2 or 4 msec) * * Mode Control (one of the following):
Autonomous Set (normal or internal), or External Gain Set (forced), or Continuity Test, or Leakage Test, or Levitate Test, or ADC Test.
* * Low Cut Filters (in or out), * * Low Cut Frequency, (8,12,18 or 27 Hz) * * Notch Filters (in or out) * * External Gain Codes, (xl, x4, x16, x64, x256, x1024, x4096, or x16384) * * Preamp Gain, (x8, x32, x128 or x512 APU Modes Math Configuration (same for all channels~
* * Window length "n" value (64, 128, 256 or 512 samples per window~
* * Math control Information:
IPW algorithm "n" value (0 to 31~
Source Type Code (dynamite or vibrator) si~;
-25~
The purpose of the Acquisition Call is to cause specified groups of adaptive SGR's to commence data acquisition.
The two types of Acquisition Calls are the dynamite type and the vibrator type, depending on the source of energy.
5 The Acquisition Call can also specify one or more adaptive SGR's as Source Units, and controls either the firing of dynamic charges or the synchronized starting of vibrators.
The content of each acquisition call is shown in Table II.

1~5~516 rA-BrlE-II
SGR Call Sequences:
No. of call sequences First sequence - start line/station no.
First sequence - stop line~station no.
Second sequence Last sequence Source Unit Information:
No. of source units (max = 16) First source unit line~station no.
First source unit shot delay in milliseconds four digits 9,999 msec. max Second source unit line/station no.
Second source unit shot delay Last source unit line/station no.
Last source unit shot delay File no. or record no. (Control Unit sequential, max ^- 999) File multiplicity (stacking only) normalize or don't normalize after this sweep, sequential sweep no. in present series (up to 64 sweeps), Time zero delay in milliseconds:
max. value = 9,999 msec; min. value = lO0 msec (i.e., at end of this time-out all SGR's start recording) 1~5~

~ Reset Call is used to interrupt a series of VIBROSEIS Acquisition Calls, in which the seismic data collected are suspect and therefore to be discarded. The data may be "suspect" because a vibrator malfunctioned or 5 the wrong acquisition parameters were set up in the Pro-gram Call, etc. The Reset Call clea~s the memory and "resets" the weighting and stacking functions. Thus, a new series of Acquisition Calls may begin immediately after a ~eset Call (assuming that the originai cause of 10 the suspect data has been corrected). Note that a Reset Call is sent to the same groups of SGR's that the Acquisi-tion Calls were being sent to.
The Test Call is transmitted to a single SGR
immediately following a Program Call, to verify the line/
15 station number assignments and to run a set of internal self-tests. Note that separate Test Calls are required for each channel being used. If any of the self-tests fail, one of several buzzer sequences will indicate the nature of the failure.
The following tests are run during a Test Call:
EPROM Tests; Operating Program Tests; Buffer Memory Tests;
APU Functions Tests; Data Acquisition Tests; Geophone String Tests; Bubble Memory Subsystem Tests; HSDL Loop-Back Test; and Environment, Power Supply and Battery Vol-25 tages. Each of these tests is described below:
1. EPROM Tests - The EPROM in the SGR stores the "Boot Program" along with its resident calculated checksum.
In this test, a new checksum is computed on the EPROM
contents and compared against its stored checksum.
2. Operating Program Test - The operating memory stores the SGR operating program tests along with its resi-dent calculated checksum. In this test, a new checksum is computed and compared to a checksum in EPROM.
3. Buffer Memory Tests - The first location (i.e., a single byte) of every lK byte block of the 256K byte buffer memory will be used to first write and then read two predefined data patterns (hex 00 and then to FF).

i~85~;

. APU Functions Test - Two predefined 8 sample-long traces are passed to the APU ror stacking.
5. Geophone String Tests - Open, short, leakage and impulse tests are run on the geophone string con-nected to the channel under test.
6. Bubble Memory Subsystem Tests - A fixed pattern oE
data is written to the test ~rack (lK b~tes) of the bubble ~emory. lhe track is then read and the data compared to the original data ror errors.

7. HSDL Loop-3ack Test - A loop is formed electrically connecting the ~SDL link driver output to the link receiver input inside the recorder. (No external connections are required.) The HSDL output and input are then simultaneously enabled, and test data is transmitted. The received data is then compared to the original data for errors.

8. Environment, Power Supply and Battery Voltage - Cor-rect operation of the temperature and humidity sensing circuits is verified. The power supply output voltage levels, along with the battery vol-tage, are checked.

9. Data Acquisition Subsystem Test - Each input channel of the DAS is tested to detect faults in the geophone analog signal processing, including analog-to-digital conversions; notch filter; low cut filters, preampli-fier and gain-ranging amplifier.
Unlike prior seismometer group recording systems which required manually collecting the tapes or the like from the recorder, seismic data accumulated in the solid 30 state magnetic bubble memory subsystem of the adaptive SGR
can be electronically downloaded via the high speed data link to a transcriber which formats the seismic data on a standard multi-track tape suitable for utilization with a main frame computer. As such, the electronic components 35 of the SGR can be effectively sealed from its harsh oper-ating environment so as to prolong its reliable opera-tions.

i~5~5~ti From the foregoing, it will be understood that this invention provides an improved method and apparatus for seismic geophysical exploration. It will now be appa-rent to those skilled in the art that the foregoing dis-5 closure and description of the invention is illustrativeand explanatory thereof, and various changes may be made in the const-uction o~ the improved method and apparatus within the scope of the claims without departing from the spirit of the invention. Exemplary of such change that is lO clearly contemplated as falling within the scope of the claims would be to electronically download operating pro-grams into the adaptive SGR of the present invention using coded signals transmitted by the remote control unit and received by the adaptive SG~'s RF receiver.

Claims

WHAT WE CLAIM IS:

1. In a seismic exploration system, an adap-tive seismometer group recorder having enhanced operating capabilities for acquiring, processing and storing seismic signals from at least one geophone. comprising:
(a) a first solid state memory;
(b) input means with the adaptive seismom-eter recorder for electronically downloading a plur-ality of operating programs providing menus of recorder operating parameters into the first solid state memory of the seismometer group recorder;
(c) processing means with the seismometer group recorder responsive to coded signals trans-mitted from a remote control unit for selecting sets of recorder operating parameters from the menus of recorder operating parameters provided by the oper-ating programs to acquire and process the seismic signals; and (d) a second solid state memory for storing acquired and processed seismic data from the processing means.

2. The adaptive seismic recorder of Claim 1 wherein said processing means comprises:
(a) a microprocessor;
(b) a RF receiver in communication with the microprocessor; and (c) electronically programmable memory in communication with the microprocessor having oper-ating programs contained therein for use by the microprocessor to evaluate the coded signals received by the RF receiver.

3. The seismometer group recorder of Claim 2 wherein said electronically programmable memory includes nonvolatile memory.

4. The seismometer group recorder of Claim 2 wherein said electronically programmable memory includes volatile memory.

5. The seismometer group recorder of Claim 1 further including output means with the adaptive seismom-eter group recorder for electronically transferring the seismic signals stored in the second solid state memory to a transcriber processing unit.

6. The seismometer group recorder of Claim 1 wherein the first and second solid state memory comprises a magnetic bubble memory subsystem.

7. The seismometer group recorder of Claim 1 further including verification means to verify operating programs electronically downloaded into the seismometer group recorder for completeness and accuracy.

8. The seismometer group recorder of Claim 5 wherein said input means and output means comprise:
a high speed data transceiver responsive to coded signals from the processing means for electron-ically downloading operating programs into the first solid state memory and for electronically transfer-ring seismic signals stored in the second solid state memory to the transcriber unit.

9. The seismometer group recorder of Claim 1 wherein the menus of recorder operating parameters pro-vided by the operating programs are selected from the group comprising:
(a) acquisition parameters;
(b) recorder operating instructions;
(c) seismic signal processing instruc-tions; and (d) diagnostic instructions.

10. The seismometer group recorder of Claim 9 wherein said acquisition parameters include seismic signal sampling rate, notch filter selection, low-cut filter fre-quency selection, preamplifer gain, and external gain.

11. The seismometer group recorder of Claim 9 wherein said recorder operating instructions include the frequency of the coded signal to which said processing means responds.

12. The seismometer group recorder of Claim 9 wherein said processing instructions include weighting and stacking algorithms and window links for processing the seismic signals.

13. The seismometer group recorded Claim 1 wherein said first and second solid state memory comprise high capacity, battery backed up CMOS DRAM memory.

14. A method of seismic exploration for acquiring, processing and storing seismic signals with an adaptive seismometer group recorder deployed in a region of exploration interest comprising the steps of:
(a) transmitting a first coded signal from a remote unit to the seismometer group recorder to select a first set of recorder operating parameters from a first menu of recorder operating parameters provided by first operating programs resident therein;
(b) acquiring and processing seismic sig-nals generated by at least one geophone electrically coupled to each seismometer group recorder in accor-dance with the selected first set of recorder oper-ating parameters;
(c) electronically downloading into the seismometer group recorder second operating programs providing a second menu of seismic recorder operating parameters;
(d) transmitting a second coded signal to the seismometer group recorder to select a second set of recorder operating parameters from the second menu of seismic recorder operating parameters provided by the second operating programs resident therein; and (e) acquiring and processing the seismic signals in the seismometer group recorder in accor-dance with the selected second set of seismic recorder operating parameters.

15. The method of Claim 14 wherein the first and second menus of recorder operating parameters provided by the first and second operating programs can include:
(a) acquisition parameters;

(b) recorder operating instructions;
(c) seismic signal processing instruc-tions; and (d) diagnostic instructions.

16. The method of Claim 14 further including:
(a) storing a plurality of seismic signals acquired and processed in accordance with the selected recorder operating parameters in a solid state memory of the seismometer group recorder;
(b) retrieving the seismometer group recorder to a central location; and (c) electronically coupling the retrieved seismometer group recorder to a transcriber unit for electronically transferring thereto the plurality of seismic signals stored in a solid state memory.

17. In a seismic exploration system, an adap-tive seismometer group recorder having enhanced operating capabilities for acquiring, processing and storing seismic signals generated from at least one geophone electrically coupled thereto in response to seismic energy imparted into the earth, comprising:
(a) control means for transmitting coded signals to the seismometer group recorder to select a set of recorder operating parameters for acquiring, processing and storing seismic signals therein;
(b) processing means with the seismometer group recorder responsive to the transmitted coded signals for configuring the seismometer group recorder to acquire, process and store seismic sig-nals in accordance with selected recorder operating parameters by selecting the recorder operating param-eters from a menu of recorder operating parameters resident in the seismometer group recorder; and (c) means for electronically downloading additional operating programs, providing additional menus of recorder operating parameters, into the seismometer group recorder, such that the processing means responsive to code signals transmitted by the control means can reconfigure the seismometer group recorder to acquire, process and store seismic sig-nals in accordance with the recorder operating param-eters selected from additional menus of recorder operating parameters provided by the additional oper-ating programs electronically downloaded into the seismometer group recorder.

18. In the system of Claim 17 further including verification means with seismometer group recorder for verifying the accuracy and completeness of the electroni-cally downloaded additional operating programs.

19. A method of seismic exploration for acquiring, processing and storing seismic signals with an adaptive seismometer group recorder comprising the steps of:
(a) electronically downloading operating programs providing menus of recorder operating param-eters into the adaptive seismometer group recorder;
(b) transmitting first coded signals to the seismometer group recorder to select a first set of recorder operating parameters from the first menu of recorder operating parameters to acquire, process and store seismic signals generated by at least one geo-phone electrically coupled to the seismometer group recorder; and (c) transmitting second coded signals to select a second set of recorder operating parameters from the first menu of recorder operating parameters to acquire, process and store seismic signals gener-ated by at least one geophone electrically coupled to the seismometer group recorder.

20. The method of Claim 19 further including the steps of:
(a) transmitting third coded signals to the seismometer group recorder to select a first set of diagnostic tests from the menu of recorder operating parameters to check the functionality of the seismom-eter group recorder; and (b) transmitting fourth coded signals to the seismometer group recorder to select a second set of diagnostic tests from the menu of recorder oper-ating parameters to check the functionality of the seismometer group recorder.

21. The method of Claim 17 further including the step of electronically downloading second operating programs providing second menus or recorder operating par-ameters into the adaptive seismometer group recorder.

22. The method of Claim 17 further including:
(a) assigning the seismometer group recorder a field location identifier with the first coded signal; and (b) transmitting a third coded signal to the seismometer group recorders to verify the field location identifier.

23. The method of Claim 21 further including transmitting a third coded signal to select diagnostic tests from the menu of recorder operating parameters to verify functionality of the seismometer group recorder.

24. A method of seismic exploration with an adaptive seismometer group recorder and a remote control unit comprising the steps of:
(a) electronically downloading operating programs providing menus of recorder operating param-eters into the seismometer group recorder;
(b) programming each seismometer group recorder to respond only to coded signals transmitted from the remote control unit containing its unique individual serial identification code;
(c) transmitting a program call in accor-dance with Table I to the seismometer group recorder to assign a field location identifier and to select an initial set of recorder operating parameters from the menu of recorder operating parameters;
(d) transmitting a test call from the remote control unit to the seismometer group recorder to verify the field location identifier assignment and initiate diagnostic tests of the seismometer group recorder; and (e) transmitting an acquisition call in accordance with Table II from the remote control unit to the seismometer group recorder to activate the seismometer group recorder to acquire, process and store seismic data in accordance with the selected recorder operating parameters.

25. The method of Claim 24 further including:
(a) retrieving the seismometer group recorder to a central location and electronically coupling them to a transcriber unit; and (b) electronically transferring the stored seismic signals to the transcriber unit.