b'Geophysics in the surveysNewsGeological Survey of South Australia: The nuts and bolts of a major gravity uploadThe Geological Survey of Southexport quality \x1bag associated with it. Thenumber of stations acquired (with and Australia (GSSA) is proud to say that allmajority of surveys get this tick, allowingwithout repeats), survey company, for public-domain ground gravity surveysthe data to be automatically harvested.whom the survey was acquired, gravity conducted in South Australia areThe very few surveys without the exportserial numbers, the Exploration Licence available to the public via SARIG. Thatquality tick are still available via companynumber(s) on which the survey was is, all the ones were aware of. Were alsoreports, but are not visible on the spatialconducted, gravity meter details, base aware that not all surveys are visiblelayer on SARIG. station and survey tie details, DGPS and online in the spatial layer on SARIG.elevation info, gravity datum, geodetic This is an issue that GSSA geophysicistsIn rare instances we need to back- datum, con\x1ddentiality status.are rectifying as a matter of priority, ascalculate observed gravity from Bouguer we recognise this is a primary way toAnomalies (and elevations). This is a lastThe survey is given a unique survey code, discover new surveys. It will also leadresort, only occurring if a request for theusually in the form YYYYAXX, where to a new state gravity grid productfull data from the exploration companyYYYY is the year, A is the letter A, and XX (tentatively scheduled for early 2024). fails. In these rare situations we haveis the n th survey for that year that weve in-house spreadsheets to calculate theprocessed. In surveys prior to around The process of identifying, cleaning,original data, and we clearly state if1990, the A would be replaced by a formatting, compiling metadata,survey data has been back-calculated inB or E or I (or other letters) depending uploading, and releasing ground gravityour database. on the nature of the survey. The codes surveys is a broadly linear process, withwith an E letter are interpreted as complexities each step of the way. Formatting the \x1dles is arguably thescienti\x1dc notation numbers in some most time-consuming step. In order tosoftware packages, and so we no longer Identifying \x1dles associated withupload ground gravity data to the gravityuse this naming system and just use ground gravity surveys is relativelymodule in the SA Geodata database,an A. The metadata is loaded into the straightforward. South Australianwe need to upload a minimum ofgravity module, followed by the \x1deld Government company reportingeight columns of data per survey (notdata. The database will reject the data if o\x1ccers keep detailed records of all dataincluding survey metadata). These \x1deldsvalues within the upload \x1dle fall outside submitted as part of annual technicalare a point number (of no more thanallowable parameters. As an example, reports, including all geophysicaleight digits), easting and northing anda positive latitude value cannot be data. These records allow the GSSAzone (or latitude and longitude), threeuploaded.geophysicists to easily compile a list ofheights (AHD and both ausgeoid09 \x1dles that require upload to SARIG. Theand ausgeoid2020 ellipsoidal heights),Once the survey is loaded, we commence data \x1dles are automatically attachedthe observed gravity, and a grid \x1bagwork on the next survey. However, we to open\x1dle envelopes after a \x1dve-year(indicating if the point is to be includedare currently managing many surveys in con\x1ddentiality period, but are notin the state grid product. Y = yes, includebatches. We have constructed a simple automatically added to the spatial layersin the grid, N = no, do not include indashboard to allow us to compile all online. Complexities can arise if a portionthe grid). The database will use thissurveys requiring upload, and then we of a survey is missing. The companyinformation to calculate the Free-Aircan clean all the \x1dles at once, format reporting o\x1ccers are authorised toand Bouguer Anomalies (both slab andthem at once, etc. At the time of writing contact exploration companies directlyspherical cap Bouguer Anomalies arewe are 59.04% through the process of and can usually track down missingcalculated). Not all survey data comeuploading 176 surveys.information. with all three heights, and we usuallyThe story doesnt end there. Once the need to calculate one or two of them. Forsurveys are on SA Geodata, they still need Cleaning a ground gravity surveythis we regularly utilise the free online usually involves a quick check of thecalculators available on the Geoscienceto be loaded to the spatial layer on SARIG. data \x1dle(s) to ensure that there are noAustralia website. This is a partially automated process, formatting issues. The majority of surveywith aspects of the process requiring data \x1dles are \x1dne, but occasionally anWe also need to remove repeatmanual intervention. First, the data is asterisk or column formatting issueobservations. The architects of the gravityautomatically harvested into a corporate will sneak in. We identify the issue andmodule built the database so it wontdata layer and becomes available for modify a copy of the \x1dle accordingly. Weaccept two gravity values at the sameinternal government use. This occurs never alter the original company data; wepoint within the same survey. Generallyautomatically every month but can be create copies and work on those. There isthis is a simple step of \x1dltering a stationpushed through upon request. Next, always a backup. type \x1deld and removing repeated points,we need to notify our GIS experts that but occasionally this isnt an optionthe corporate layer needs to be added We create a shape\x1dle of the surveyand we need to look at repeated pointto SARIGto update the current gravity and view the \x1deld data spatially. Herenumbers, or matching easting/northingstation layer. This isnt automatic and is we undertake QA/QC work and ensurecombinations. undertaken on an as-needs basis. The that the survey has been acquired overspatial data is made SARIG-friendly and the correct tenement(s), and compareOnce the data has been whittled downthe SARIG team is alerted to the update. nearby elevation and observed gravityto the essential information, we compileThe layer is \x1drst added to a test instance values from overlapping and adjacentas much of the survey metadata asof SARIG (UAT; User Acceptance Testing) surveys. i.e., we check that the survey \x1dtspossible (including but not limitedto ensure everything is in order, before an in. Each survey in the database has anto: Survey name, start and end dates,ok is given and the test layer is replicated DECEMBER 2023 PREVIEW 20'