_______________________________________________________________________________ _______________________________________________________________________________ GEOPHYSICAL SURVEY DATA REPORT _______________________________________________________________________________ _______________________________________________________________________________ Date : 24 May 2015 This readme file describes the equipment and specifications of a geophysical airborne survey conducted by Thomson Aviation Pty. Ltd. The readme also summarises the data processing parameters and procedures used. CLIENT DETAILS --------------- Company Flown by : Anton Rada Rada Engineering Pty. Ltd Company Processed: Anton Rada Rada Engineering Pty. Ltd Client : Lottah Mining Pty Ltd Company Job : Thomson 14103 AIRBORNE SURVEY EQUIPMENT: ------------------------- Aircraft : Multirotor UAV X4 Magnetometer : Fluxgate 3 axes Magnetometer Resolution : +/- 0.15 nT Magnetometer Compensation : Post Flight Magnetometer Sample Interval : 20 Hz, Approx Data Acquisition : Mike DAQ V1.0 Sensor Number : 845 GPS Navigation System : UBLOX L6 GPS Receiver AIRBORNE SURVEY SPECIFICATIONS ------------------------------ Area: Hampshire Tasmania L13 Flight Line Direction : 090 - 270 degrees Flight Line Separation : 25 metres Tie Line Direction : 180 - 000 degrees Tie Line Separation : 100 metres Sensor Clearance : 20 metres (MTC) Survey flown : May 2015 DATUM and PROJECTION -------------------- Datum : Geodetic Datum of Australia 94. GDA94 Projection : Map Grid of Australia. MGA Zone : Zone 55 _____________________________________________________________________________________________ DATA PROCESSING : MAGNETIC DATA _____________________________________________________________________________________________ ____________________________________ MAGNETIC PROCESSING FLOW ____________________________________ The final magnetic data processing was performed using the following processing flow: - Aircraft magnetic data QC - Diurnal magnetic data QC - System parallax removal - Fluxgate scale, offste, orthogonality calibrations applied. - Post flight magnetic compensation applied. - Diurnal variation removal and addition of the mean diurnal base value - IGRF removal and addition of mean IGRF value. - levelling using polynomial Tie line levelling, - Micro levelling if required - Reduction to the pole. - Gridding using Minimum Curvature algorithm MAGNETIC QUALITY CONTROL ------------------------ The processing of the magnetic data firstly involved the routine quality control in the field of both the aeromagnetic and diurnal data during the acquisition phase. Any data found not meeting the required specifications were reflown. MAGNETIC PARALLAX CORRECTION ---------------------------- The total magnetic intensity aircraft data was firstly corrected for the effects of system parallax. The parallax parameters were determined and checked from the results of opposing test line flights. MAGNETIC DIURNAL CORRECTION --------------------------- The base station magnetometer data was edited and merged into the main database. The aeromagnetic data was corrected for diurnal variations by subtracting the observed magnetic base station deviations. There were no magnetic storms recorded by the diurnal monitoring station during the survey. The mean value was then added back to the data. MAGNETIC IGRF CORRECTION ------------------------ The data was corrected for the regional gradient of the International Geomagnetic Reference Field (IGRF). The IGRF was calculated for every point along the lines with respect to GPS height using the IGRF Model for 2010 with secular variation applied. The mean IGRF value was then added back to the data. MAGNETIC PROFILE LEVELLING -------------------------- The magnetic traverse line data was then statistically levelled from the tie line data using Intrepid polynomial levelling. The steps involved in the tie line levelling were as follows: - A primary tie line was chosen as a reference tie. - All other ties were levelled to this tie line using 1st degree polynomial adjustment. - lines were adjusted individually to minimize crossover differences, using 2nd degree polynomial adjustments. Any residual flight line effects were removed using Intrepid micro levelling techniques and the resultant line data saved as a separate field. MAGNETIC GRIDDING ----------------- The data was gridded to a cell size of 20% of line spacing using a Spline algorithm. _________________________________________________________________________________________________ For further information on the data processing please contact: Anton Rada at radaengineering@dodo.com.au directly. _________________________________________________________________________________________________