b'Data trends Data trends.des (description) is a (tiny) report At least one additional alias is required .prj (projection) defines the data/ for potential field data to be immediately projection used usable:.ddf is essentially the .dfn rearranged intoa monolithic list for machineLine Type (flight or tie)reading Line direction information is sometimes The .dat and .dfn files are the barein the .des file but not in a form minimum, and we need to encouragepredictable for parsers, and often there (or enforce) greater use of the other files.is no .des file to parse.This requires the ASEG to publish suchAliasesrecommendations, and would tie in with the idea that the ASEG should host aSet names do not come out of devices GDF2 checking website. or surveyors and even units can depend What do I like about GDF2? It doeson the device. Aliases can identify the not mandate column names andimportant columns for automating Tim Keepingthereforehas been used for almostinteroperability for significant data Associate Editor all types ground and airbornesuch as final_mag or final K/Th/U. for geophysical datamanagementgeophysicalsurveys, as well asThe shorter the better for maximum and analysis in Kim Frankcombes adaptationbackwards compatibility.technical-standards@aseg.org.au for electricalsurveys (ESF). WhatThe examples above show the we neednow (GDF3) is a set ofdominance of airborne mag and predictable data names without toorad data, but we need to cater ASEG GDF3? much interference. for data from other survey types. I was discussing my Tech Standards woesWhat columns are significant for with a colleague who replied pretendMachine consumable gradiometry? Do we need a column you are developing GDF3, what would itrecording instrument direction (NED People want data to work out of theor END) or a single .des file entry? look like? box. GDF2 already has aliases for base Should all tensors be present? EM For the uninitiated, the ASEG GDF2data: produces numerous slices so can we standard includes multiple ASCII files: assign an alias to an array?X (including datum and projection).dat (data) is a fixed width text file withY (including datum and projection) Such matters are being considered by the columns of data where each line is aFiducial ASEG Naming Convention subcommittee sample location Line Number and any ideas relating to the evolution of .dfn (definition) defines the .dat fixedFlight Number GDF2 are welcome (technicalstandards@widths and what sits inside them Date aseg.org.au).Free subscription to Preview online Non-members of the ASEG can now subscribe to Preview online via the ASEG website. Subscription is free. Just go to https://www.aseg.org.au/publications/PVCurrent to sign up. You will receive an email alert as soon a new issue of Preview becomes available. Stay informed and keep up-to-date by subscribing now!!NB: ASEG Members dont need to subscribe as they automatically receive an email alert whenever a new issue of Preview is published.OCTOBER 2022 PREVIEW 36'