AU2015258825A1

AU2015258825A1 - Borehole location identification

Info

Publication number: AU2015258825A1
Application number: AU2015258825A
Authority: AU
Inventors: Craig Charles Schlenter
Original assignee: Detnet South Africa Pty Ltd
Current assignee: Detnet South Africa Pty Ltd
Priority date: 2014-05-15
Filing date: 2015-05-12
Publication date: 2016-06-09
Also published as: ZA201602946B; WO2015176080A2; WO2015176080A9; AU2015101869A4; AU2015101869A6; WO2015176080A3

Abstract

in a blasting system positional data for a borehole or detonator generated by the use of a remote reference source is corrected by applying thereto a correction factor, determined by comparing absolute positional information of a reference location to positional information of the reference location generated by the use of the remote reference source.

Description

BOREHOLE LOCATION IDENTIFICATION 8ACNGROUND 0];;Η8 gITVhiy Ή ϋ N £00011 This invention relates generally to s blasting system and mors particularly to the accurate Identification of the geographical position of boreholes m a blasting system, 10002] A ANSI (global navigation satellite system) can be used to establish the geographical oosliion of each borehole in a plurality or boreholes ;n a masting system, vein a my pegs so oi accuracy: Nonetheless, the accuracy of GN88 data is subject to extraneous rasters sucti as meteorological conditions, ephemens and clock errors, and the like. 1 ypicatiy the accuracy or GNSS positional data may be subject to a variation or tolerance or several meters.

[00031 Electronic detonators can execute timing intervals, used to determine or control a blasting pattern, with an accuracy of the order of milliseconds or ceiter 1 ne decent ot tms degree of timing accuracy is however negated, to some extent, oy the relatively inaccurate Dosihonai data if such data is used to establish blast timing ue. the time instant at wnicn a detonator Is Ignited. (00041 Various techniques have been proposed to address positional data errors which are attributable to operating factors associated through the use of a GN88. in UH rlobOxo a feed transmitter supplies correction data over a transmission link to a device which provides data on the position of each borehole in a blasting system. The correction data presumably could bo provided using the RTCfvl standard 1 he provision ot this type ot Transmission iinn can however be cumbersome. fCIOOS] An object of the present invention, in one respect. Is to eliminate the need for a real time transmission link to supply correction data of the kind referred to.

SUMMARY OF THE INVENTION 1O0OS] T he invention provides a method of establishing positional data for each borehole In a plurality of boreholes in a blasting system, wherein each borehole is respectively associated with at least one detonator, the method including the steps of; 1. establishing a base station with known geographical positions! information. 2 at the base station over a given time interval recording, as a function oi time. ON AS information which is derived at least from a GNSS receiver, 3. over sa;d given time Interval, or a subset thereof, utilising a data logger to log, as a function of time, GNSS information for each of a plurality of boreholes in the Masting system, and a unique identity for each borehole or for each detonator, and 4. using the geographical positional Information, referred to In step (1), the GNSS Information recorded ;n step (2) and the GNSS information logged in step (3} to derive corrected positional information for each borehole or detonator.

The term "GNSS information” as used herein may Include any information derivable from a GNSS system, as indicated In step (2) and additionally or alternatively, derived from a related data source or system component including out not limited to any combination of trie following sources of information: « information relating to a clock or an oscillator in an earth-based device; * information relating to a clock of a satellite-based device; * Information relating to the phase of a transmission signal from a satellite-cased device; ® GNSS epherneds information; ® Information about errors In data transmitted from a satellite-based device derived from a SBAS (satellite based augmentation system) or other sources including internet accessible GNSS correction data; « positional information; and ^ any data available In the following GNSS related standards; o RINEX - receiver independent exchange format; o RICH; ~ Radio Technical Commission for yarltlme Services; ο. S13AS satellite based augmentation system; and o WAAS - wide area augmentation system. (00071 A benefit of the invention lies in the fact that the base station need nor be ;n on cm communication, real tune or otherwise, with the data logger However, the GNSS wtormanon recorded at the base station Is recorded over at least the time interval during which the data logger is used to record GNSS information relating to borehole or detonator positions. In step (4\ the data from stops (1). (2) and (3), are used to derive tne borecole or detonator positions; information using time as a common reference. (0003; Algorithms used to correct the data are described Inter alia in the manual for the RTKUB software library from www.rtkiib.com. While the details may be complex, in simple terms the known location of the base station enables the determination ot errors associated with the range data received from each satellite. This in turn allows correction oata to be derived to compensate for these errors. The correction data may in turn be used to adjust the ranqe data recorded on the data logger thus allowing the calculation of a more accurate position than would be available without the correction data. Additional data iron· other sources such as atmospheric models, internet based correction data or SBAS and the like, may be used to correct for atmospheric related errors, and satellite position errors, to remove fauity satellite data, and the like. fOOOS'J The invention further extends to a method of generating positional data for a borehole or of a detonator in a blasting system wherein positional data for the borehole or for the detonator, generated by the rise of a remote reference source is corrected by applying thereto a correction factor, determined by comparing absolute positional Information of a reference location to positional information of the reference location generated by the use of the remote reference source.

BRIEF DESCRIPTION OF THE DRAWING

[00101 The Invention Is further described by way of example with reference to the accompanying drawing which is a schematic representation of one manner m wmcn me method of the invention can be implemented.

DESCRIPTION OF PREFERRED EMBODIMENT

[0011] The accompanying drawing Illustrates part of a blasting system 10 which includes a plurality of boreholes 12A, 12B. 12C ... 12N formed in a body of rock 14. At ieasi one detonator 16A. 168 ... 16N is placed In each respective borehole. This is exemplary only and non-limiting for, depending on requirement, two or more detonators can be placed m a single borehole. Each borehole is filled, as ;s known In the art, with explosive material 18.

[00121 In this example the detonators 16 are Interconnected by means of respective branch lines 20A. 2QB ... SON to a main harness 24. In use a blasting machine x6 is connected to the harness 24. A plurality of blasting machines and harnesses may be used if required.

[00131 A base station 30 is established near the blasting system 10 at a suitable she. i he geographical position of the base station is accurately given by means of positional data 32 determined and validated In a plurality of ways known In the art. A plurality or base stations may be usee if desired. ΓΟΟΙ41 The base station induces a data recorder on [001 SI A processor 40 is used in the Implementation of the method of the invention, i be processor may be mobile, associated witn tne case station, associateo wnn u::iww:p machine, associated with the data recorder 34 or be installed at a control location. : no invention Is not 0 mi fed in this respect. In one embodiment the processor 40 w provsoea w conjunction with a hand-held data logger 42 which is used by an operator 44 [0016] The recorder 34 has the capability of logging GNSS information received from at mast one GNSS data source 46 or derived from local information such as an infernal ciock associated with a GNSS receiver, on a time basis. Tbe recorder 34 may also mg information from other data sources suet: as internat-baseo GNbS dots correction sousoes, [0017] in practice the operator 44 goes to each of the boreholes izw, rub in airy suaao-e sequence. Each borehole or detonator nas a unique identify 50A, 50B ... PON associated with it. The operator Is required to position the logger 42 as close as is possible to each borehole or detonator, in turn. When the logger is at a borehole 12N the respective identity data 50K is logged and, substantially simultaneously. GNSS data from the oara source sc is logged to record the geographical position of the borehole 12K as determines oy me eaia source This is done on a urns casts.

[0018] Additional GNSS data may be logged, if desired, as the operator 44 moves between the boreholes 12 In order to track the movement of the operator between the boreholes. I he Identity data 5GK may be associated with a particular detonator and not with a borehole in which the detonator is positioned, it is possible for the Identity data to he assignee automatically, sequent-ally or otherwise, to the detonators by me earn ;ogger it reguneo. me boreholes with multiple detonators, the data logger may also record information about tne depth of the detonator in the borehole derived through suitable means such as user input or stored iniemallv in the detonator at the time of manufacture, based lor example on me detonator harness length or the length of a branch line to the detonator The detonators may of course simoly be numbered sequentially in a borehole according to a given conversion o.g detonator 1 may be at the bottom of a borehole, detonator 2 may oe me first nignei up detonator from detonator 1, and so on. CODIS] The operator logs the borehole or detonator position, In the aforementioned manner, durinq a known lime interval and, during that same time interval the recorder 44 operates automatically without requiring real-time communication with me data logger ox. 100201 Once the positions of all of the boreholes or detonators have been logged oy tne operator, at any appropriate time thereafter, the data from the recorder 34 is retrieved. i'00211 in the processor 40 a programme is executed to analyse the recorded data 34 arm to anoiy tne data 32 whicn is accepted as correctly sceowymg use eu-sx-on m χχ- t..--~.;xv,- w^uu·::, a.·-determine those errors in the data held in the recorder 34 which are attributable to variations in the accuracy of the data obtainable from the data source 46. A table 60 of corrections, applicable to the data In the recorder 34, on a time basis, Is generated by the programme.

[0022:1 Data 62 from the data logger 42 is also held on a time scale but linked. In respect of each borehole or detonator, to the unique identity of that borehole or the identities of tire detonators associated with the respective borehole, Correction factors available irom me table 60 are applied to the data 62 by a correlator 64, using time as a common factor. i he correlation process produces a table 66 of corrected borehole data wmch consists or corrected geographical or positional data of each borehole linked to the unique identmer of that borehole or the Identity of each of the detonators associated with the respective borehole.

[00231 in carrying out the aforementioned process it Is assumed that variations which could affect the accuracy of the data logged by the logger 42, affect, substantially to the same extent, the accuracy of the data 32 retained :n the recorder o4. as toe true geograpn-cs· position of the base station 30 is known the error in the data 32 m the recoroer o4 can no determined, u is taken that the same degree of error manifests itself In the data 02 m me new [0024] The corrected positional data 66 is available for subsequent use {step 70) e.g. In determining time delays in the individual detonators. These delays can be programmed into the detonators 12 using the blasting machine 26 or any other appropriate mechanism l ne corrected borehole data 66 may be displayed on a geograpmcei map or on or m otner smrame craphical representation, using an appropriate tool to aid with blast design tor me Planting system 10.

[00251 Additions! corrections may be appiied to the data 32; the borehoie data 62; the corrected data 60 o- the corrected borehoie data 86. based on data derived from various sources e.g. atmospheric modelling, 8BA:i;. VVAAS and the like. Data deemed incorrect may be removed from processing e g. a satellite may transmit an incorrect position and this may be ignored as :s known in the art.

Claims

1, A method of establishing positional data for each borehole in a plurality of boreholes ;n a blasting system, wherein each borehole Is respectively associated with at least one detonator, the method including the steps of: {1} establishing a hose station with known geographical positional information, (2; at the base station over a given time Interval recording, as a function ot time, GNSS information which Is derived at least from a GNSS receiver, (3) over sa-d given tone interval, or a subset thereof, utilising a Oats iogger to log, as a function of tone, GNSS Information for each of a plurality of boreholes In the blasting system, and a unique identity for each borehole or for each detonator, arm (4) using the geographical positional Information, referred to ;n step (1:, the GNbS Information recorded in step (2} and the GNSS Information logged in step (3} to derive corrected positional information for each borehole or detonator.

2. A method according to claim 1 wherein the GNSS irmiemation includes information derived from at least one of the following sources of information: ' information relating to a clock or an oscillator m an earth-based device: '·· information relating to a clock of a satellite-based device: » information relating to the phase of a transmission signal from a satellite-based device; » GNSS ephemeris information: » information about errors in data transmitted from a satellite-based device derived from a SSAS (satellite based augmentation system) or other sources including internet accessible GNSS correction data. * positional information; and * any data available in the following GNSS related standards; o RiNEX - receiver independent exchange format; o RTCM - Radio Technical Commission for Maritime Services; o SSAS — sateiiite based augmentation system; and o VVAAS -- wide area augmentation system.

3 A method according to claim 1 or 2 which includes the step of using the data logger to allocate said unique identity for each borehole or for each detonator.

4 a method according to claim A 2 or 3 wherein the corrected positional elate tor eacn borehole or detonator is determined, at least ;n part, by estabiisning an enw m we GNSS positional information for the base station, and using tnat error m coueci me GNSS information, logged by tne Pars logger, tor seen co-enow Os monau:. A method of generating positional data for a borehole or of a detonator in a masting svstem wherein positional data for the oorenoie or ter the detonator, genesaieu oy we use of a remote reference source Is corrected by applying tnereto a correction vactou determined by comparing absolute positional information or a rereisnee woavon positional information of the reference location generated oy the use ot me remote reference source.