 
========
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
             		

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