This file contains information on : - Located data formats - Gridded data formats - Plot File Formats - Survey equipment and specifications - Data processing specifications. GENERAL -------- Project: GOLDFIELDS HENTY PROJECT AREA: RED HILLS Survey Company: GEO INSTRUMENTS Job Number: #9002 Date: 20th March 2000 LOCATED DATA ------------- Data type: Final ASCII located data set. File: 9002REDHILLS.ldt located data Archive Media: CD (Joliet format) Field Width/decimals Description ............................................................................. Column 1 10.0 line number 'TFNNNaA' ** see Format below ** Column 2 10.1 WGS84 northing (metres, AMG Zone 55 ) Column 3 10.1 WGS84 easting (metres, AMG Zone 55 ) Column 4 10.1 AGD84 northing (metres, AMG Zone 55 ) Column 5 10.1 AGD84 easting (metres, AMG Zone 55 ) Column 6 8.0 fiducial Column 7 12.6 time (decimal hours) Column 8 8.2 radar altimeter (meters) Column 9 8.2 GPS altitude (meters) Column 10 8.2 Digital terrain Model (meters) Column 11 10.2 compensated magnetics (nanoTeslas) Column 12 10.2 diurnal magnetics ((-)nanoTeslas ) Column 13 10.2 final magnetics (nanoTeslas) Column 13 8.2 final magnetics, auto gain control (nanoTeslas) ## see below ## Column 13 11.5 final magnetics, first vertical derivative (nanoTeslas/m) Column 14 6.0 Raw Total Count (Counts) Column 15 6.0 Raw Potassium Count (Counts) Column 16 6.0 Raw Uranium Count (Counts) Column 17 6.0 Raw Thorium Count (Counts) Column 18 7.1 Corrected Total Count (Counts) Column 19 7.1 Corrected Potassium Count (Counts) Column 20 7.1 Corrected Uranium Count (Counts) Column 21 7.1 Corrected Thorium Count (Counts) NOTES: ------- Null Value = -999 ** LINE NUMBERING: Line numbers are in the form 'TFNNNaA' where T = Line type (2 = traverse, 4 = tie, 9 = test) F = Flight number NNN = line sequence number a = Area number A = line attempt number eg: 2101012 is traverse, flight 1, line 10, area 1, attempt 2 ## Auto Gain control parameters used: Half Window 100 points. Base removed over 300 points. GRID DATA: ---------- Algorithm: Akima spline Grid mesh size: 10 x 10 metres Grid filter: None Format: ER Mapper. Grid Files: Description: DTM Digital terrain Model (meters) TMI Total magnetic Intensity - Diurnal, IGRF, Levelled (nanoTeslas) TMI_1VD_LINE First vertical derivative on line data of Total magnetic Intensity TMI_1VD_CONV First vertical derivative on Gridded data of Total magnetic Intensity TMI_AGC Auto gain control on Total magnetic Intensity Total_C Corrected Total Count (Counts) Potas_C Corrected Potassium Count (Counts) Uran_C Corrected Uranium Count (Counts) Thorium_C Corrected Thorium Count (Counts) PLOT FILE FORMATS ----------------- Map files are in HPGL2 format, and can be copied directly to an HPGL2 printer. DATA ACQUISITION ----------------- AIRBORNE SURVEY SPECIFICATIONS Survey flown: Traverse line spacing: 25 metres Traverse line direction: 090/270 degrees Tie line spacing: 250 metres Tie line direction: 000/180 degrees Survey height: Magnetometer on boom at 30m agl Spectrometer detector in aircraft at 30m agl Data acquisition: Geo Instruments Model G2001 system Aircraft: Bell 206BIII helicopter VH-JWF MAGNETOMETER Type: Geometrics G822A Caesium vapour Resolution: 0.001 nT Recording interval: 0.1 sec (approx. 3.0 metres sampling) Compensation: RMS AADCII real time system Installation: Magnetometer mounted on forward boom GAMMA SPECTROMETER Type: Exploranium GR820 256 channel Crystal volume: Downward looking 16.8 litres Recording interval: 1.0 sec (approx. 30 metres sampling) Spectral windows: Window Range Energy (MeV) From To From To Total Count: 33 238 0.41 2.81 Potassium (K40): 116 133 1.37 1.57 Uranium (Bi214): 140 158 1.66 1.86 Thorium (Tl208): 205 238 2.41 2.81 Cosmic: - - 3.00 >6.00 Calibration: Real-time automatic gain stabilisation based on tracking of the Thorium peak NAVIGATION Flight path navigation: Real time satellite Differential GPS system Navigation equipment: Ashtec Model GG21 GLONASS/GPS receivers Flight path record: WGS84 lat/long coordinates converted to Radar altimeter: Sperry AA210 GPS base station locations: Fugro, virtual base station. DATA PROCESSING --------------- MAGNETIC DATA The magnetic data has been corrected for regional gradient by subtraction of IGRF model 2000.1 and secular variation model 1995-2000. Diurnal variations have been removed. System parallax has been removed. Tieline levelling has been applied. Microlevelling has been applied. The mean diurnal value and the IGRF base value have been added to the data. GAMMA SPECTROMETRIC DATA NASVD noise reduction applied using 4 retained components Live time corrected Cosmic and aircraft background removed Radon correction method: Spectral ratioing Temperature and pressure corrected Compton stripping: Alpha: 0.2589 Beta: 0.3610 Gamma: 0.7559 Height attenuated to: 30 metres mean terrain clearance Total count: 0.006205/metre Potassium count: 0.00754/metre Uranium count: 0.00506/metre Thorium count: 0.006441/metre Sensitivity constants: VH-JWF Total Count - 1ngray/hr: 20.28 cps NOTE: Conversions not used. Potassium - 1%: 70.1 cps Uranium - 1ppm: 8.3 cps Thorium - 1ppm: 3.88 cps Calibration ranges: Bairnsdale, Victoria (hovering) Canberra, ACT (pad calibrations) BIBLIOGRAPHIC REFERENCE Surveyed by: GeoInstruments Pty Ltd, SYDNEY Geo Instruments job number: 9002 Processed by: GeoInstruments Pty Ltd, AR Grid production by: GeoInstruments Pty Ltd Grid production date: March 2000