GB1440073A - Time synchronisation particularly for seismic work - Google Patents
Time synchronisation particularly for seismic workInfo
- Publication number
- GB1440073A GB1440073A GB3245172A GB3245172A GB1440073A GB 1440073 A GB1440073 A GB 1440073A GB 3245172 A GB3245172 A GB 3245172A GB 3245172 A GB3245172 A GB 3245172A GB 1440073 A GB1440073 A GB 1440073A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulse
- master
- monostable
- output
- seismic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
- G01V1/22—Transmitting seismic signals to recording or processing apparatus
- G01V1/223—Radioseismic systems
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G7/00—Synchronisation
- G04G7/02—Synchronisation by radio
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Environmental & Geological Engineering (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geophysics (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
1440073 Clock systems SEISMOGRAPH SERVICE (ENGLAND) Ltd 11 July 1973 [11 July 1972 24 Nov 1972] 32451/72 and 54435/72 Heading G3T [Also in Division H4] In an arrangement for obtaining correct time synchronization at remote points without direct communication of time between those points and particularly for seismic survey operations, separate timing units are provided one for use at each point and each having a constant frequency oscillator from which are derived timing pulses and the units are brought together and inter-connected for synchronizing the pulses and then located at their respective operative points. TIMING UNITS Fig. 1 illustrates a typical unit which may be used either as a master or as a slave unit. It comprises a 1 MHz quartz oscillator which is maintained at a constant temperature (75‹C). The oscillator output is shaped by a Schmitt trigger 12 the I MHz output of which is divided down by a decade counter 14 to give a pulse every 10 secs at outputs 16, 18. Each pulse initiates drive current of adjustable duration in a monostable multivibrator 20, which operates contacts of a relay 26. Closure of the relay contacts in a remote slave unit is used to trigger a seismic signal by actuating a blaster or other seismic wave source such as a vibrator, as described with reference to Fig. 3 (not shown). Their simultaneous closure in a master unit causes a time datum to be recorded in a seismic recorder. To start the recorder in the master unit ahead of a seismic 'shot', the last four decade counter outputs D4 to D7 are decoded by a decoder-timer 38 from which an ouput pulse can be provided at any time in steps of 1 m.sec. relative to one of the 10 sec pulses. This output pulse initiates drive current of adjustable duration from a monostable MV 40 which operates a relay 42 to start the recorder. SYNCHRONIZING. Fig. 2 To synchronize the seismic signal trigger pulse in the or each slave unit so as to coincide with the time datum pulse recorded in the master unit, each unit is provided with a monostable 56 and a Schmitt trigger 50. Closure of a switch 52 in the slave unit permits a pulse from monostable 56 in the master to reset all counters in the decade counter 14 of the slave, the monostable 56 pulse being initiated by the decoder timer 38 output which initiates the time reference pulse from monostable 20. Square waveforms ( e.g. at 200 KHz 40% duty cycle for synchronization are produced by an AND gate 70 which receives the Dl and D6 outputs from decade counters 14. The waveforms A and B, Fig. 4 (not shown), from the master and slave respectively are applied to a gate 70 in the master, the output of gate 70 being a square waveform C (Fig. 4) indicating the degree of coincidence. The output of the gate 70 is connected via a diode (not shown) to a meter 47 which measures a D.C. level substantially proportional to the pulse width of waveform C, i.e. to the degree of coincidence. From a count of the meter deflections from zero to a maximum and back to zero again, the difference between the oscillator frequencies in the master and slave units can be calculated. The frequency of the slave unit oscillator is adjusted to decrease the frequency difference. In operation, an operator at the shot point closes a firing switch and the seismic signal is triggered by the next pulse from monostable 20 in the slave unit. The pulse from monostable 20 in the master is recorded simultaneously. At the same instant a return check pulse is sent from the blaster 80, Fig. 3 (not shown), to set a monostable 40 and allow pulses to pass from timer 38 to system start-output 44 for transmission via radio link to the master. The recorder is also connected to a geophone array (not shown).
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3245172A GB1440073A (en) | 1972-07-11 | 1972-07-11 | Time synchronisation particularly for seismic work |
DE19732334996 DE2334996C3 (en) | 1972-07-11 | 1973-07-10 | Seismic facility |
CA176,035A CA1012618A (en) | 1972-07-11 | 1973-07-10 | Time synchronisation, particularly for seismic work |
JP48078899A JPS5047663A (en) | 1972-07-11 | 1973-07-11 | |
BE6044241A BE802222A (en) | 1972-07-11 | 1973-07-11 | TIME SYNCHRONIZATION, IN PARTICULAR FOR SEISMIC WORK |
FR7325380A FR2192334B1 (en) | 1972-07-11 | 1973-07-11 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3245172A GB1440073A (en) | 1972-07-11 | 1972-07-11 | Time synchronisation particularly for seismic work |
GB5443572 | 1972-11-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1440073A true GB1440073A (en) | 1976-06-23 |
Family
ID=26261378
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3245172A Expired GB1440073A (en) | 1972-07-11 | 1972-07-11 | Time synchronisation particularly for seismic work |
Country Status (4)
Country | Link |
---|---|
CA (1) | CA1012618A (en) |
DE (1) | DE2334996C3 (en) |
FR (1) | FR2192334B1 (en) |
GB (1) | GB1440073A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2128056A (en) * | 1982-09-17 | 1984-04-18 | Gen Electric | Computer controlled devices |
US4843588A (en) * | 1982-09-17 | 1989-06-27 | General Electric Company | Programmable radio frequency communications device capable of programming a similar device |
GB2304938A (en) * | 1995-09-06 | 1997-03-26 | Cheuk Fai Ho | Master and one by one slave synchronisation |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2545952B1 (en) * | 1983-05-13 | 1987-03-20 | Omega Electronics Sa | DEVICE FOR ELECTROMAGNETIC TRANSMISSION OF AN EVENT IN A DISTURBED MEDIUM |
DE102007060264A1 (en) | 2007-12-14 | 2009-06-18 | GeoForschungsZentrum Potsdam Stiftung des öffentlichen Rechts | Pulse generator, in particular for exciting seismic waves |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3416631A (en) * | 1966-12-30 | 1968-12-17 | Texas Instruments Inc | Digital remote firing system |
FR2153563A5 (en) * | 1971-09-15 | 1973-05-04 | Commissariat Energie Atomique |
-
1972
- 1972-07-11 GB GB3245172A patent/GB1440073A/en not_active Expired
-
1973
- 1973-07-10 DE DE19732334996 patent/DE2334996C3/en not_active Expired
- 1973-07-10 CA CA176,035A patent/CA1012618A/en not_active Expired
- 1973-07-11 FR FR7325380A patent/FR2192334B1/fr not_active Expired
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2128056A (en) * | 1982-09-17 | 1984-04-18 | Gen Electric | Computer controlled devices |
US4843588A (en) * | 1982-09-17 | 1989-06-27 | General Electric Company | Programmable radio frequency communications device capable of programming a similar device |
GB2304938A (en) * | 1995-09-06 | 1997-03-26 | Cheuk Fai Ho | Master and one by one slave synchronisation |
Also Published As
Publication number | Publication date |
---|---|
FR2192334B1 (en) | 1979-01-26 |
CA1012618A (en) | 1977-06-21 |
DE2334996B2 (en) | 1980-10-09 |
FR2192334A1 (en) | 1974-02-08 |
DE2334996A1 (en) | 1974-02-21 |
DE2334996C3 (en) | 1981-06-19 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |