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   			GEOPHYSICAL SURVEY DATA REPORT
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							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
          
  
  

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				DATA PROCESSING   : MAGNETIC DATA
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   MAGNETIC PROCESSING FLOW
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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.





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  For further information on the data processing please contact:
  Anton Rada at radaengineering@dodo.com.au directly.
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