======== GENERAL ======== -------------------------------------------------------------- Project: Heli EM Survey Survey : Dundas Survey By: GEO Instruments Survey Base: Zeehan --------------------------------------------------------------- ================= DATA ACQUISITION ================= AIRBORNE SURVEY SPECIFICATIONS Electromagnetic System Hummingbird 5 frequency EM system. Data acquisition: Geo Instruments Model G2002 system Geotech Hummingbird system Aircraft: Squirrel helicopter MAGNETOMETER Type: Geometrics G822A Caesium vapour Resolution: 0.001 nT Recording interval: 0.1 sec (approx. 3.5 metres sampling) Installation: Magnetometer sensor mounted in HEM bird. HUMMINGBIRD COIL SPECIFICATIONS: Bird 1 Channel : 1 2 3 4 5 -------------------------------------------------------------- Freq (Hz) : 7000 6600 980 880 34000 Orientation : CX CP CX CP CP Coil Separation (m) : 6.26 6.26 6.01 6.01 4.93 ================================ DATA Re-PROCESSING 20 sep 2002 ================================ The previously high altitude levelled electromagnetic data was used to calculate Apparent resistivities for all 5 frequencies using the Inversion technique in the Geosoft HEM module. The resultant resistivities were gridded and microlevelled to produce the new grids. The located data contains both raw resistivities and microlevelled resistivities. GRIDDED DATA FILES: ------------------- Files: Extensions as for processed data below. Format: ER Mapper Datum: AGD84 Projection: TMAMG Zone: 55 Algorithm: Minimum Curvature Grid mesh size: 20 x 20 metres Log option: Saved as log Grid Files: LOG_cp34k_AResistINV LOG_cp6k_AResistINV LOG_cp385_AResistINV LOG_cx7k_AResistINV LOG_cx980_AResistINV Grid files are saved as LOG of Apparent Resistivity ohms/m calculated using the INVERSION technique. ==================== LOCATED DATA FORMAT ==================== Data type: ASEG GDF2 Archive Media: CDs (Joliet format) The ASEG GDF2 located data contains the following fields : FIELD: DESCRIPTOR: ------ ----------- line Line number X, Easting (metres) Y, Northing (metres) LINETYPE 2 = Traverse, 4 = Tie Fid, Fiducial (main system) fltno, Flight Num Tym, Local Time (HH.ddddddd) Magraw, Raw Uncorrected magnetometer nT's magbase, BaseMag Value nT's magfin, Levelled IGRF corrected Mag nT's IP1F, Quad Phase Coil 1 Unlevell 7001 Hz CoAX ip1lev, In Phase Coil 1 Levelled 7001 Hz CoAX ip1zero, Zero Level Computed IP2F, In Phase Coil 2 Unlevell 6606 Hz CoPL ip2lev, In Phase Coil 2 Levelled 6606 Hz CoPL ip2zero, Zero Level Computed IP3F, In Phase Coil 3 Unlevelled 980 Hz CoAX ip3lev, In Phase Coil 3 Levelled 980 Hz CoAX ip3zero, Zero Level Computed IP4F, In Phase Coil 4 Unlevelled 385 Hz CoPl ip4lev, In Phase Coil 4 Levelled 385 Hz CoPl ip4zero, Zero Level Computed IP5F, In Phase Coil 5 Unlev 34133 hz CoPl ip5lev, In Phase Coil 5 Levelled 34133 hz CoPl ip5zero, Zero Level Computed Q1F, Quad Phase Coil 1 Unlevelled 7001 Hz CoAX q1lev, Quad Phase Coil 1 Levelled 7001 Hz CoAX Q1zero, Zero Level Computed Q2F, Quad Phase Coil 2 Unlevelled 6606 Hz CoPL q2lev, Quad Phase Coil 2 Levelled 6606 Hz CoPL Q2zero, Zero Level Computed Q3F, Quad Phase Coil 3 Unlevelled 980 Hz CoAX q3lev, Quad Phase Coil 3 Levelled 980 Hz CoAX Q3zero, Zero Level Computed Q4F, Quad Phase Coil 4 Unlevelled 385 Hz CoPl q4lev, Quad Phase Coil 4 Levelled 385 Hz CoPl Q4zero, Zero Level Computed Q5F, Quad Phase Coil 5 Unlev 34133 hz CoPl q5lev, Quad Phase Coil 5 Levelled 34133 hz CoPl Q5zero, Zero Level Computed rf2fin, App Resistivity Log Ohms/m (derived 6606 Hz Copl) rf4fin, App Resistivity Log Ohms/m (derived 385 Hz Copl) rf5fin, App Resistivity Log Ohms/m (derived 34133 Hz Copl) RAlt, Radar Altimeter (metres above surface) GAlt, Gps Height (metres above Geoid Ref AHD) dtm, Geoid height (metres ref AHD) Baro, Barometric pressure hectoP Oat Outside Air Temperature Deg Celsius Radalt_EM_Bird Elevation of EM bird above ground level. cx980_AResistINV Apparent cx980 Resistivity (ohms/m) INVERSION technique cp34k_AResistINV Apparent cp34k Resistivity (ohms/m) INVERSION technique cp6k_AResistINV Apparent cp6k Resistivity (ohms/m) INVERSION technique cx7k_AResistINV Apparent cx7K Resistivity (ohms/m) INVERSION technique cp385_AResistINV Apparent cp385 Resistivity (ohms/m) INVERSION technique Logcx980_AResistINV Log Apparent cx980 Resistivity (ohms/m) INVERSION technique Logcp34k_AResistINV Log Apparent cp34k Resistivity (ohms/m) INVERSION technique Logcp6k_AResistINV Log Apparent cp6k Resistivity (ohms/m) INVERSION technique Logcx7k_AResistINV Log Apparent cx7K Resistivity (ohms/m) INVERSION technique Logcp385_AResistINV Log Apparent cp385 Resistivity (ohms/m) INVERSION technique Logcx980_AResistINVMicro Microlevelled Log Apparent cx980 Resistivity (ohms/m) INVERSION technique Logcp34k_AResistINVMicro Microlevelled Log Apparent cp34k Resistivity (ohms/m) INVERSION technique Logcp6k_AResistINVMicro Microlevelled Log Apparent cp6k Resistivity (ohms/m) INVERSION technique Logcx7k_AResistINVMicro Microlevelled Log Apparent cx7K Resistivity (ohms/m) INVERSION technique Logcp385_AResistINVMicro Microlevelled Log Apparent cp385 Resistivity (ohms/m) INVERSION technique cx980_AResistINVMicro Microlevelled Apparent cx980 Resistivity (ohms/m) INVERSION technique cp34k_AResistINVMicro Microlevelled Apparent cp34k Resistivity (ohms/m) INVERSION technique cp6k_AResistINVMicro Microlevelled Apparent cp6k Resistivity (ohms/m) INVERSION technique cx7k_AResistINVMicro Microlevelled Apparent cx7K Resistivity (ohms/m) INVERSION technique cp385_AResistINVMicro Microlevelled Apparent cp385 Resistivity (ohms/m) INVERSION technique =========================================================================