b'CommentarySeismic windowUsing data from continuously recording Seismic window nodes also poses some problems with deblending or separating one shot record from the following record. The use of arrays to reduce noise also has some draw backs Michael Micenkowith intra array variations in elevation Associate Editor for Petroleum or velocity and directionality causing a distortion of the signal that a\x1fects some E mick@freogeos.com.au surface consistent processes and AVO for example. Perhaps the solution is to have Maintaining data quality in pointthe relative quality of a survey. Signalclosely spaced nodes and use digital array source and receiver acquisition strength varies with di\x1ferent sourceforming to simulate a surface array and types and parameters, and is di\x1bcult toenhance weak signal and attenuate noise. put a number on, but it can be improvedAnd, unlike a geophone array, the use of This article was inspired by two articlesby vertical stacking of shots and usingdigital array forming can be reversible.published in the January 2024 First Breakmultiple sensors at each receiverlocation.magazine (see references).If we go further down this path the end There has been a trend in recent yearsresult will be to blanket the survey area Several years ago, when I was workingfor cable-less nodes distributed as pointwith closely spaced receivers. There are on a seismic crew, the observer andreceivers to replace cabled geophonesome places in the world where we still client representative would check everyarrays. This has led to some discussiondo that, but not many. shot record to ensure the recorded dataof the advantages and disadvantages of was good enough to use. If it wasnt,the two systems (Ourabah 2024). Source it was reshot, or the parameters wereand receiver arrays have been used forReferenceschanged. This system worked well whiledecades to reduce noise such as groundSpencer L Rowse, S.L and R. Heath, 2024. Has trace counts were low (24-96 channels)roll in the \x1eeld while single point nodesthe importance of signal been forgotten in the but now surveys can have thousandssupposedly record enough data tosignal-to-noise ratio of land seismic acquisition? of channels on distributed, cable-lesse\x1fectively model and eliminate noise inFirst Break: 42, January 2024nodes. It is no longer possible to viewthe processing centre.Ourabah A., 2024. Revisiting the single sensor shot records in real time. So, how do wevs array debate in the light of new nodal system maintain quality? One way to allow forWhen I last worked with a seismic crewtechnology. First Break: 42, January 2024.poor signal is to increase trace count15-20 years ago, we experimented with and fold. But Rowse and Heath (2024)the use of point source receivers and say increasing fold is a brute force waywere able to remove the troublesome to maintain data qualityit uses thenoise that turned out to be non-random weight of numbers to allow for dead ordi\x1fractions rather than random noiseBREAKING NEWSmissing traces. The trend now is to lower(this was the subject of a talk I gave at signal-to-noise ratio as source energy isa recent WA Branch ASEG meeting). InMick Micenko will, once reduced to minimise interference fromthis case rather than nodes, which wereagain, be representing blended records and noise increasesnot yet mainstream, we used bunchedPreview and the ASEG as a with the move away from receiver arraysgeophones at the receiver locations. Thismedia representative at the to single point receivers. They suggestexperiment worked well, and the key was that rather than fold or trace density,to reduce the station spacing from 12.5annual AEP Conference and some knowledge of the signal strengthto 8 m so that the noise was sampled wellExhibition (formerly APPEA)is necessary to estimate and compareenough to avoidaliasing. 2 21 07 1Tensor Research Geophysical Software Research and ServicesModelVision magnetic & gravity interpretation system QuickDepth, AutoMag, UBC Model Builder Training, consulting, research & developmentRPD Mapping - a new service for large scale magneticrock property & depth mappingsupport@tensor-research.com.auwww.tensor-research.com.au34 PREVIEWAPRIL 2024'