		AIRBORNE GEOPHYSICAL DATA

			

Survey name:			Clear Lake Property
Location:			Mayo,Yukon,Canada
Job No.:                        8138
Client:                         Copper Ridge Explorations Inc. 
Survey date:     		July 17th to August 2nd, 2008 
Survey company name:            Geotech Ltd.
Total line-km:                  235
Archive creation date:		September 18, 2008

Aircraft type:                  Astar B3, registration C-GAVO
Base of operation:              Mayo, Yukon
 
Airborne Magnetometer
Model:				Geometrics 
Type:				Cesium-vapour
Sample Interval:		10 Hz (0.1 seconds); 2-3 metres
Sensitivity:			0.02 nT
Mount:                          Towed bird, 13 metres below helicopter
Height above ground:		61 metres

Airborne EM
Model:				Geotech Ltd. 
Type:				VTEM
Number of channels:		26 (0.120 - 9.245 ms) 
Sample Interval:		10 Hz (0.1 seconds); 2-3 metres
Mount:				Towed ring, 42 metres below helicopter
Transmitter Loop diameter:	26 m
Transmitter Number of turns:	4
Current:			200 Amp
Peak Dipole moment:		535, 966 nIA  
Pulse width:			4.8 ms
Receiver Loop diameter:		1.2 m
Receiver number of turns:	100
Receiver effective area:	113.1 m2
Height above ground:		39 metres

The VTEM decay sampling scheme is shown in Table 3 below. Twenty-six time measurement 
gates were used for the final data processing in the range from 120 ms to 9245 ms, as shown in Table 5.
	Table 3 – Decay Sampling Scheme
VTEM Decay Sampling scheme
Array	( Microseconds )
Index	Time Gate	 Start	End	Width
0	0			
1	10	10	21	11
2	21	16	26	11
3	31	26	37	11
4	42	37	47	11
5	52	47	57	10
6	62	57	68	11
7	73	68	78	11
8	83	78	91	13
9	99	91	110	19
10	120	110	131	21
11	141	131	154	24
12	167	154	183	29
13	198	183	216	34
14	234	216	258	42
15	281	258	310	53
16	339	310	373	63
17	406	373	445	73
18	484	445	529	84
19	573	529	628	99
20	682	628	750	123
21	818	750	896	146
22	974	896	1063	167
23	1151	1063	1261	198
24	1370	1261	1506	245
25	1641	1506	1797	292
26	1953	1797	2130	333
27	2307	2130	2526	396
28	2745	2526	3016	490
29	3286	3016	3599	583
30	3911	3599	4266	667
31	4620	4266	5058	792
32	5495	5058	6037	979
33	6578	6037	7203	1167
34	7828	7203	8537	1334
35	9245	8537	10120	1584

        

Mean terrain clearance:         74 m
Navigation type:		NovAtel's CDGPS receiver
				(on the tail of the helicopter)
Radar altimeter: 		Terra TRA3000/TRI-40



Survey block		Traverse/Tie Line spacing (m)	Area (Km2)	Line-km’s	Flight direction	Line numbers
Clear Lake Property		Traverse: 200		  42.5		  240.3	 	    N 45° E		L1000 – L1500
				Tie: 1900						    N 135° E	        T1580 – T1600





  


		AIRBORNE GEOPHYSICAL DIGITAL ARCHIVES


There are two (2) main directories:

	Data		contains databases, grids and maps, as described below.
			 	 			 
	Report		contains a copy of the report and appendixes in PDF format.



Table 5 – Geosoft GDB Data Format.
Channel Name	Description
Channel Name	Description
X:	X positional data (meters – WGS 84, UTM zone 8 north)
Y:	Y positional data (meters –WGS 84, UTM zone 8 north))
Z:	GPS antenna elevation (meters - ASL)
Radar:	Helicopter terrain clearance from radar altimeter (meters - AGL)
RadarB:	EM Bird terrain clearance from radar altimeter (meters - AGL)
DEM:	Digital elevation model (meters)
Gtime:	GPS time (seconds of the day)
Mag1:	Raw Total Magnetic field data (nT)
Mag2:	Diurnal corrected Total Magnetic field data (nT)
Magfin:	Leveled Total Magnetic field data (nT)
Basemag:	Magnetic diurnal variation data (nT)
SF[10]:	dB/dt 120 microsecond time channel (pV/A/m4)
SF[11]:	dB/dt 141 microsecond time channel (pV/A/m4)
SF[12]:	dB/dt 167 microsecond time channel (pV/A/m4)
SF[13]:	dB/dt 198 microsecond time channel (pV/A/m4)
SF[14]:	dB/dt 234 microsecond time channel (pV/A/m4)
SF[15]:	dB/dt 281 microsecond time channel (pV/A/m4)
SF[16]:	dB/dt 339 microsecond time channel (pV/A/m4)
SF[17]:	dB/dt 406 microsecond time channel (pV/A/m4)
SF[18]:	dB/dt 484 microsecond time channel (pV/A/m4)
SF[19]:	dB/dt 573 microsecond time channel (pV/A/m4)
SF[20]:	dB/dt 682 microsecond time channel (pV/A/m4)
SF[21]:	dB/dt 818 microsecond time channel (pV/A/m4)
SF[22]:	dB/dt 974 microsecond time channel (pV/A/m4)
SF[23]:	dB/dt 1151 microsecond time channel (pV/A/m4)
SF[24]:	dB/dt 1370 microsecond time channel (pV/A/m4)
SF[25]:	dB/dt 1641 microsecond time channel (pV/A/m4)
SF[26]:	dB/dt 1953 microsecond time channel (pV/A/m4)
SF[27]:	dB/dt 2307 microsecond time channel (pV/A/m4)
SF[28]:	dB/dt 2745 microsecond time channel (pV/A/m4)
SF[29]:	dB/dt 3286 microsecond time channel (pV/A/m4)
SF[30]:	dB/dt 3911 microsecond time channel (pV/A/m4)
SF[31]:	dB/dt 4620 microsecond time channel (pV/A/m4)
SF[32]:	dB/dt 5495 microsecond time channel (pV/A/m4)
SF[33]:	dB/dt 6578 microsecond time channel (pV/A/m4)
SF[34]:	dB/dt 7828 microsecond time channel (pV/A/m4)
SF[35]:	dB/dt 9245 microsecond time channel (pV/A/m4)
BF[10]:	B-field 120 microsecond time channel (pVms)/(Am4)
BF[11]:	B-field 141 microsecond time channel (pVms)/(Am4)
BF[12]:	B-field 167 microsecond time channel (pVms)/(Am4)
BF[13]:	B-field 198 microsecond time channel (pVms)/(Am4)
BF[14]:	B-field 234 microsecond time channel (pVms)/(Am4)
BF[15]:	B-field 281 microsecond time channel (pVms)/(Am4)
BF[16]:	B-field 339 microsecond time channel (pVms)/(Am4)
BF[17]:	B-field 406 microsecond time channel (pVms)/(Am4)
BF[18]:	B-field 484 microsecond time channel (pVms)/(Am4)
BF[19]:	B-field 573 microsecond time channel (pVms)/(Am4)
BF[20]:	B-field 682 microsecond time channel (pVms)/(Am4)
BF[21]:	B-field 818 microsecond time channel (pVms)/(Am4)
BF[22]:	B-field 974 microsecond time channel (pVms)/(Am4)
BF[23]:	B-field 1151 microsecond time channel (pVms)/(Am4)
BF[24]:	B-field 1370 microsecond time channel (pVms)/(Am4)
BF[25]:	B-field 1641 microsecond time channel (pVms)/(Am4)
BF[26]:	B-field 1953 microsecond time channel (pVms)/(Am4)
BF[27]:	B-field 2307 microsecond time channel (pVms)/(Am4)
BF[28]:	B-field 2745 microsecond time channel (pVms)/(Am4)
BF[29]:	B-field 3286 microsecond time channel (pVms)/(Am4)
BF[30]:	B-field 3911 microsecond time channel (pVms)/(Am4)
BF[31]:	B-field 4620 microsecond time channel (pVms)/(Am4)
BF[32]:	B-field 5495 microsecond time channel (pVms)/(Am4)
BF[33]:	B-field 6578 microsecond time channel (pVms)/(Am4)
BF[34]:	B-field 7828 microsecond time channel (pVms)/(Am4)
BF[35]:	B-field 9245 microsecond time channel (pVms)/(Am4)
Lon:	Longitude data (degree – WGS84)
Lat:	Latitude data (degree – WGS84)
Plinef:	60 Hz power line monitor



Electromagnetic B-field and dB/dt data is found in array channel format between 
indexes 10 – 35, as described above.



Database VTEM_waveform.gdb in Geosoft GDB format, containing the following channels:

	Time:		Sampling rate interval, 10.416 microseconds
	Rx_voltage:	output voltage of the receiver coil (volt)
	Tx_current:	current induced by the transmitter coil (Amp)

	

•	Grids in Geosoft GRD format, as follow,
8138_BF27:		Total magnetic intensity (nT)
8138_mag3:	B-Field Time Gate 2.307 ms

A Geosoft .GRD file has a .GI metadata file associated with it, 
containing grid projection information. A grid cell size of 50 metres was used. 




 
Flown and processed by:			Geotech Ltd.
					245 Industrial Parkway North
					Aurora, Ontario, L4G 4C4
					Phone: 905.841.5004
					Fax:   905.841.0611
					www.geotech.ca