

========

GENERAL

========

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Project: 		Heli EM Survey

Client: 		Jervois Mining NL and MRT

Client Rep:		Anthony Jannink

Survey By:		GEO Instruments

GEO Number		2113 infill Area A

Survey date:		November 2001, April 2002

Survey Base:		Sheffield

Survey Area:		A1 infill: Lake Barrington Area 



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=================

DATA ACQUISITION

=================



              AIRBORNE SURVEY SPECIFICATIONS   

              Survey flown:                  November 2001 

              Traverse line spacing:         200 metres / 100 meters infill

              Traverse line direction:       000 / 180 degrees

              Tie line spacing:              2000 metres / 1000 meters infill approx

              Tie line direction:            090 / 270 degrees approx

              Survey height:                 EM towed Bird at 30m agl

              

              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.

             

              NAVIGATION              

              Flight path navigation:        Real time satellite

                                             Differential GPS system

              Navigation equipment:          Fugro OMNISTAR GPS receivers

              Flight path record:            WGS84 Easting/ Northing coordinates 

                                             

              Radar altimeter:               Collins Alt50

              GPS base station locations:    Fugro OMNISTAR(Real Time DGPS)

            



              HUMMINGBIRD COIL SPECIFICATIONS:    

     

              Bird 1  Before Julian day 67,2002, Flight 93

              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          





              Bird 2  After Julian day 67, 2002 , Flight 94

              Channel             :  	1	2	3	4	5

	      --------------------------------------------------------------

	      Freq (Hz)           : 	7000	6600	980	880	34000

	      Orientation         : 	CX	CP	CX	CP	CP

	      Coil Separation (m) :	6.25	6.25	6.03	6.03	4.79                             



		

		 NOTE: 	Processed data from Bird 2 has been adjusted to merge with 

			Bird 1 data. Coil Separation from Bird 1 has been used for

			resistivity calculations. 

			     

===============

DATA PROCESSING

===============



              MAGNETIC DATA

              The magnetic data has been corrected for regional gradient by

              subtraction of IGRF model 2001.9 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.

              

       

              ELECTROMAGNETIC DATA

              The electromagnetic data has been filtered to remove the effects of

              sferics and other noise sources.  Data has been corrected for system 

              drift by subtraction of background zero levels determined from high 

              altitude callibration data.  System parallax has been removed. 

              Apparent resistivities and depths have been calculated using both the

              Nomogram and Inversion techniques using the Geosoft HEM module.

              Inphase and quadrature channels have been levelled to remove residual 

              flight line features in apparent resistivities.   Microlevelling has 

              been applied.

                

              GRIDDING - Electromagnetics- Inphase & quad

              Algorithm:                     Minimum Curvature

              Grid mesh size:                20 x 20 metres

              Grid filter:                   None



	      GRIDDING - Electromagnetics- Resistivities

              Algorithm:                     Minimum Curvature

              Grid mesh size:                20 x 20 metres

              Grid filter:                   none

       

       	      GRIDDING - Magnetics:

              Algorithm:                     Minimum Curvature

              Grid mesh size:                20 x 20 metres

              Grid filter:                   None

              

              GRIDDING - Digital Terrain:

              Algorithm:                     Minimum Curvature

              Grid mesh size:                20 x 20 metres

              Grid filter:                   3x3 mean

              

	      	      

              LINE NUMBERING

              Line numbers are in the form 'TLLLAA' where

              T = Line type (1 = traverse, 7 = tie)

              LLL = Line sequence number

              AA = Line attempt number

              

              eg: 100201 is traverse line 2 attempt 1

                  704802 is tie lie 48 attempt 2

                  



              

                 

              BIBLIOGRAPHIC REFERENCE

              Surveyed by:                   GeoInstruments Pty Ltd

              Geo Instruments job number:    2113

              Processed by:                  GeoInstruments Pty Ltd

              Grid production by:            GeoInstruments Pty Ltd

 

 

==========================             

PROCESSED LOCATED DATA :

==========================



Format:			Geosoft GDB

Database Files:		Ax_IL_DB.GDB

			





=========================================================================

 		    LOCATED DATA FORMAT

=========================================================================



-------------------------------------------------------------------------

Field        	Field Name  		Description

-------------------------------------------------------------------------

Column  1    	LineNo_TLLLAA  		line number (TLLLAA)         

Column  2    	FlightNo           	flight          

Column  3    	Julian_Day       	julian_day  (YYYYDDD)     

Column  4    	Fid_geo        		fiducial- Geoinstruments acqusition system            

Column  5    	Fid_humm        	fiducial- HEM acqusition system            

Column  6    	Time_hh      		time (decimal hours)          

Column  7    	AGD66TMAMG55_East     	AGD66 easting  (metres, TMAMG Zone 55)

Column  8    	AGD66TMAMG55_North	AGD66 northing (metres, TMAMG Zone 55)

Column  9    	GDA94MGA55_East     	GDA94 easting  (metres, MGA Zone 55)

Column 10    	GDA94MGA55_North    	GDA94 northing (metres, MGA Zone 55)

Column 11    	AGD66GEODETIC_LAT     	AGD66 longitude (decimal degrees, GEODETIC)

Column 12    	AGD66GEODETIC_LONG    	AGD66 latitude  (decimal degrees, GEODETIC)

Column 13    	GDA94GEODETIC_LAT  	GDA94 longitude (decimal degrees, GEODETIC)

Column 14    	GDA94GEODETIC_LONG  	GDA94 latitude  (decimal degrees, GEODETIC)

Column 15    	Mag_Raw     		Raw uncompensated magnetics (nanoTeslas)

Column 16    	GPSalt_Raw        	Raw GPS height (metres)        

Column 17    	Radalt_Raw        	Raw radar altimeter (metres) 

Column 18    	Diurnal     		Diurnal magnetics (nanoTeslas)

Column 19    	IGRF     		IGRF magnetics (nanoTeslas)

Column 20    	TMI_Corrected     	Diurnal & IGRF corrected magnetics (nanoTeslas)

Column 21    	TMI_Levelled     	Levelled magnetics (nanoTeslas)

Column 22    	TMI_Final     		Final magnetics microlevelled (nanoTeslas)

Column 23    	GPSalt_Final        	Final GPS height (metres, AHD)        

Column 24    	Radalt_Final        	Final Radar altimeter (metres) 

Column 25    	DTM_Final        	Final digital terrain model (metres, AHD)

Column 26 	cx7Ki_PPM	 	Raw cx7Ki (ppm)

Column 27  	cx7Kq_PPM         	Raw cx7Kq (ppm)

Column 28  	cp6Ki_PPM         	Raw cp6Ki (ppm)

Column 29  	cp6Kq_PPM         	Raw cp6Kq (ppm)

Column 30 	cx980i_PPM       	Raw cx980i (ppm)

Column 31 	cx980q_PPM       	Raw cx980q (ppm)

Column 32 	cp880i_PPM       	Raw cp880i (ppm)

Column 33 	cp880q_PPM       	Raw cp880q (ppm)

Column 34 	cp34ki_PPM       	Raw cp34ki (ppm)

Column 35 	cp34kq_PPM       	Raw cp34kq (ppm)

Column 36  	cx7Ki_F_L         	Filtered & Levelled cx7Ki (ppm) 

Column 37  	cx7Kq_F_L         	Filtered & Levelled cx7Kq (ppm) 

Column 38  	cp6Ki_F_L         	Filtered & Levelled cp6Ki (ppm) 

Column 39  	cp6Kq_F_L         	Filtered & Levelled cp6Kq (ppm) 

Column 40 	cx980i_F_L       	Filtered & Levelled cx980i (ppm)

Column 41 	cx980q_F_L       	Filtered & Levelled cx980q (ppm)

Column 42 	cp880i_F_L       	Filtered & Levelled cp880i (ppm)

Column 43 	cp880q_F_L       	Filtered & Levelled cp880q (ppm)

Column 44 	cp34ki_F_L       	Filtered & Levelled cp34ki (ppm)

Column 45 	cp34kq_F_L       	Filtered & Levelled cp34kq (ppm)

Column 46 	cx7Ki_F_LD       	Final Levelled cx7Ki (ppm) 

Column 47 	cx7Kq_F_LD       	Final Levelled cx7Kq (ppm) 

Column 48 	cp6Ki_F_LD       	Final Levelled cp6Ki (ppm) 

Column 49 	cp6Kq_F_LD       	Final Levelled cp6Kq (ppm) 

Column 50 	cx980i_F_LD      	Final Levelled cx980i (ppm)

Column 51 	cx980q_F_LD      	Final Levelled cx980q (ppm)

Column 52 	cp880i_F_LD      	Final Levelled cp880i (ppm)

Column 53 	cp880q_F_LD      	Final Levelled cp880q (ppm)

Column 54 	cp34ki_F_LD      	Final Levelled cp34ki (ppm)

Column 55  	cp34kq_F_LD       	Final Levelled cp34kq (ppm)

Column 56  	cp34k_AResistINV  	Apparent cp34k Resistivity (ohms/m) INVERSION technique.

Column 57   	cp6k_AResistINV    	Apparent cp6k  Resistivity (ohms/m) INVERSION technique.

Column 58 	cp880_AResistINV 	Apparent cp880 Resistivity (ohms/m) INVERSION technique.

Column 59   	cx7K_AResistINV    	Apparent cx7K  Resistivity (ohms/m) INVERSION technique.

Column 60 	cx980_AResistINV 	Apparent cx980 Resistivity (ohms/m) INVERSION technique.

Column 61    	cp34k_ACondINV      	Apparent cp34k Conductivity (uS/m) INVERSION technique.

Column 62    	cp6k_ACondINV       	Apparent cp6k  Conductivity (uS/m) INVERSION technique.

Column 63  	cp880_ACondINV    	Apparent cp880 Conductivity (uS/m) INVERSION technique.

Column 64   	cx7k_ACondINV      	Apparent cx7K  Conductivity (uS/m) INVERSION technique.

Column 65 	cx980_ACondINV   	Apparent cx980 Conductivity (uS/m) INVERSION technique.

  





EM DATA:

=========



Nomenclature for field name / processing relationship:



'_ppm'			Filtered Raw data: 

'_F_L'			Filtered and levelled data.  ( FOR CDI Production )

'_F_LD'			Filtered, levelled and microlevelled data.

'_AResistINV'		Apparent Resistivity ohms/m calculated using the INVERSION technique.

'_ACondINV'		Apparent Conductivity uS/m calculated using the INVERSION technique.





GRIDDED DATA FILES:

===================

Files:	    	Extensions as for processed data above.

Format:		ER Mapper



Cell size:	20 metres

Datum:		AGD66

Projection:	TMAMG

Zone:		55





