OR/14/014 Radiometric processing - Revision history

Dbk: /* Radon background removal */

2015-08-06T08:56:28Z

Radon background removal

← Older revision		Revision as of 09:56, 6 August 2015
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	The radon correction was then computed using Minty’s method.		The radon correction was then computed using Minty’s method.

	Minty’s method (1992)<ref name="Minty">Minty, B R S. 1992, Airborne gamma-ray spectrometric background estimation using full spectrum analysis. Geophysics, Vol 57, No. 2, PP. 279–287.</ref> is a technique for estimating the background atmospheric (radon) radiation in Airborne Gamma-ray Spectrometry.		Minty’s method (1992)<ref name="Minty">Minty, B R S. 1992. Airborne gamma-ray spectrometric background estimation using full spectrum analysis. ''Geophysics'', Vol 57, No. 2, PP. 279–287.</ref> is a technique for estimating the background atmospheric (radon) radiation in Airborne Gamma-ray Spectrometry.

	The method uses the observations that:		The method uses the observations that:

Dbk: /* Calculation of effective height */

2015-08-06T08:55:39Z

Calculation of effective height

← Older revision		Revision as of 09:55, 6 August 2015
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	The height from the filtered height channel was then converted to effective height at standard temperature and pressure as per the following formula:		The height from the filtered height channel was then converted to effective height at standard temperature and pressure as per the following formula:
	{{clear}}		{{clear}}
	[[Image:14014 math2.png\|frameless\|~~center~~\|150px\| ]]		[[Image:14014 math2.png\|frameless\|left\|150px\| ]]
	{{clear}}		{{clear}}

Dbk at 08:55, 6 August 2015

2015-08-06T08:55:27Z

← Older revision		Revision as of 09:55, 6 August 2015
Line 97:		Line 97:
	The radon correction was then computed using Minty’s method.		The radon correction was then computed using Minty’s method.

	Minty’s method (1992) is a technique for estimating the background atmospheric (radon) radiation in Airborne Gamma-ray Spectrometry.		Minty’s method (1992)<ref name="Minty">Minty, B R S. 1992, Airborne gamma-ray spectrometric background estimation using full spectrum analysis. Geophysics, Vol 57, No. 2, PP. 279–287.</ref> is a technique for estimating the background atmospheric (radon) radiation in Airborne Gamma-ray Spectrometry.

	The method uses the observations that:		The method uses the observations that:
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	The technique of determination of background by full spectrum analysis is applied after the aircraft and cosmic backgrounds are removed from the observed spectrum. It involves computing the radon contribution and the uranium contribution to the low energy (0.609 MeV) and high energy (1.76 MeV) peak count rates using the observed count rates in those energy peaks and the computation of three constants determined from the radon and uranium spectra. In turn, the radon contribution to the background in the standard uranium window is computed and added to the aircraft and cosmic backgrounds to get the total uranium channel background. And finally the computed uranium background is used to estimate the total count and potassium backgrounds. Thorium background is computed independently from the aircraft and cosmic backgrounds.		The technique of determination of background by full spectrum analysis is applied after the aircraft and cosmic backgrounds are removed from the observed spectrum. It involves computing the radon contribution and the uranium contribution to the low energy (0.609 MeV) and high energy (1.76 MeV) peak count rates using the observed count rates in those energy peaks and the computation of three constants determined from the radon and uranium spectra. In turn, the radon contribution to the background in the standard uranium window is computed and added to the aircraft and cosmic backgrounds to get the total uranium channel background. And finally the computed uranium background is used to estimate the total count and potassium backgrounds. Thorium background is computed independently from the aircraft and cosmic backgrounds.

	~~====Reference====~~
	~~Minty, B R S. 1992, Airborne gamma-ray spectrometric background estimation using full spectrum analysis. Geophysics, Vol 57, No. 2, PP. 279–287.~~

	The radon correction values were then removed from the filtered background and cosmic corrected values Kbg, Ubg, Thbg and Tcbg		The radon correction values were then removed from the filtered background and cosmic corrected values Kbg, Ubg, Thbg and Tcbg
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	==Special stripping==		==Special stripping==
	The background corrected count rates in the three windows must be stripped to give the counts in the potassium, uranium and thorium windows that originate solely from potassium, uranium and thorium. The stripping ratios a, b, g, a and g must be determined from measurements over calibration pads. The three principal stripping ratios (a, b, and g) increase with altitude above the ground as shown in Table 2.The background corrected data is then stripped. Before stripping the coefficients are corrected for variation from height as follows:		The background corrected count rates in the three windows must be stripped to give the counts in the potassium, uranium and thorium windows that originate solely from potassium, uranium and thorium. The stripping ratios a, b, g, a and g must be determined from measurements over calibration pads. The three principal stripping ratios (a, b, and g) increase with altitude above the ground as shown in Table 2. The background corrected data is then stripped. Before stripping the coefficients are corrected for variation from height as follows:

	: Where:		: Where:
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	==Levelling==		==Levelling==

	Some leveling was required after radiometric correction. This was done using proprietary tie-line leveling and micro-leveling software routines where required.		Some leveling was required after radiometric correction. This was done using proprietary tie-line leveling and micro-leveling software routines where required.

	==Noise adjeusted singular value decompostion (NASVD)==		==Noise adjeusted singular value decompostion (NASVD)==

	Noise adjusted singular value decomposition (NASVD) was used to considerably enhance low signal to noise regions of the survey.		Noise adjusted singular value decomposition (NASVD) was used to considerably enhance low signal to noise regions of the survey.

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	\| nT		\| nT
	\|-		\|-
	\| ~~compensated_mag _right_sensor~~		\| compensated_mag_right_sensor
	\| Total Magnetic Intensity (compensated)		\| Total Magnetic Intensity (compensated)
	\| nT		\| nT
	\|-		\|-
	\| ~~compensated_mag _tail_sensor~~		\| compensated_mag_tail_sensor
	\| Total Magnetic Intensity (compensated)		\| Total Magnetic Intensity (compensated)
	\| nT		\| nT
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	\|}		\|}

			==Reference==

	[[Category:OR/14/014 Project/logistics and processing report \| 05]]		[[Category:OR/14/014 Project/logistics and processing report \| 05]]

Dbk: Protected "OR/14/014 Radiometric processing" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) [cascading]

2015-05-05T15:07:23Z

Protected "OR/14/014 Radiometric processing" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) [cascading]

← Older revision	Revision as of 16:07, 5 May 2015
(No difference)

Dbk: /* Calculation of effective height */

2015-04-13T11:50:28Z

Calculation of effective height

← Older revision		Revision as of 12:50, 13 April 2015
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	The height from the filtered height channel was then converted to effective height at standard temperature and pressure as per the following formula:		The height from the filtered height channel was then converted to effective height at standard temperature and pressure as per the following formula:
	{{clear}}		{{clear}}
	[[Image:14014 math2.png\|~~thumb~~\|center\|~~400px~~\| ]]		[[Image:14014 math2.png\|frameless\|center\|150px\| ]]
	{{clear}}		{{clear}}

Dbk: /* Products delivered */

2015-04-13T11:10:48Z

Products delivered

← Older revision		Revision as of 12:10, 13 April 2015
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	==Products delivered==		==Products delivered==
	The following products have been delivered. It is noted that all products are digital and have been presented in the project coordinates reference system ~~(See Section 2.2)~~.		The following products have been delivered. It is noted that all products are digital and have been presented in the project [[OR/14/014_Part_1:_Survey_information #Geographical coordinates systems used \| coordinates reference system]].

	===Geosoft Grids===		===Geosoft Grids===

Dbk: /* Energy calibration */

2015-04-10T07:38:35Z

Energy calibration

← Older revision		Revision as of 08:38, 10 April 2015
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	\| Upper		\| Upper
	\|-		\|-
	\| ~~'''~~Cs-137~~'''~~		\| Cs-137
	\| <p align="center">648</p>		\| <p align="center">648</p>
	\| <p align="center">732</p>		\| <p align="center">732</p>

Dbk: /* Energy calibration */

2015-04-10T07:38:22Z

Energy calibration

← Older revision		Revision as of 08:38, 10 April 2015
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	\| colspan="2" \| '''Channel Limits'''		\| colspan="2" \| '''Channel Limits'''
	\|-		\|-
	\| ~~'''~~Lower~~'''~~		\| Lower
	\| ~~'''~~Upper~~'''~~		\| Upper
	\| ~~'''~~Lower~~'''~~		\| Lower
	\| ~~'''~~Upper~~'''~~		\| Upper
	\|-		\|-
	\| '''Cs-137'''		\| '''Cs-137'''
	\| <p align="center">~~'''~~648~~'''~~</p>		\| <p align="center">648</p>
	\| <p align="center">~~'''~~732~~'''~~</p>		\| <p align="center">732</p>
	\| <p align="center">~~'''~~54.08~~'''~~</p>		\| <p align="center">54.08</p>
	\| <p align="center">~~'''~~61.09~~'''~~</p>		\| <p align="center">61.09</p>
	\|}		\|}

Dbk: /* Geosoft Grids */

2015-04-10T07:36:51Z

Geosoft Grids

Dbk: /* Geosoft Grids */

2015-04-10T07:36:11Z

Geosoft Grids

← Older revision		Revision as of 08:36, 10 April 2015
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	\| '''Magnetic Grids'''*		\| '''Magnetic Grids'''*
	\|-		\|-
	\| * tmi.grd \|\| Total Magnetic Intensity (TMI) - nT		\| • tmi.grd \|\| Total Magnetic Intensity (TMI) - nT

	\|-		\|-

← Older revision		Revision as of 08:36, 10 April 2015
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	===Geosoft Grids===		===Geosoft Grids===
	{\|		{\|
	\| '''Magnetic Grids'''*		\| '''Magnetic Grids'''
	\|-		\|-
	\| • tmi.grd \|\| Total Magnetic Intensity (TMI) - nT		\| • tmi.grd \|\| Total Magnetic Intensity (TMI) - nT

	\|-		\|-
	\| tmi_hg_enhanced.grd \|\| TMI with Horizontal Gradient enhancement (nT)		\| • tmi_hg_enhanced.grd \|\| TMI with Horizontal Gradient enhancement (nT)
	\|-		\|-
	\| tmi_igrf.grd \|\| IGRF Correcxted TMI (nT)		\| • tmi_igrf.grd \|\| IGRF Correcxted TMI (nT)
	\|-		\|-
	\| tmi_igrf_1VD.grd \|\| First Vertical Derivative of TMI (nT/m)		\| • tmi_igrf_1VD.grd \|\| First Vertical Derivative of TMI (nT/m)
	\|-		\|-
	\| tmi_igrf_analytical_signal.grd \|\| Analytical Signal of TMI-( nT/m)		\| • tmi_igrf_analytical_signal.grd \|\| Analytical Signal of TMI-( nT/m)
	\|-		\|-
	\| tmi_igrf redp.grd \|\| Reduction to the Pole of TMI (nT)		\| • tmi_igrf redp.grd \|\| Reduction to the Pole of TMI (nT)
	\|-		\|-
	\| '''Radiometric Grids'''		\| '''Radiometric Grids'''
	\|-		\|-
	\| Potassium masked.grd \|\| Processed Potassium with offshore data masked out (%)		\| • Potassium masked.grd \|\| Processed Potassium with offshore data masked out (%)

	\|-		\|-
	\| Potassium.grd \|\| Processed Potassium (%)		\| • Potassium.grd \|\| Processed Potassium (%)

	\|-		\|-
	\| Thorium masked.grd \|\| Processed Thorium with offshore data masked out (ppm)		\| • Thorium masked.grd \|\| Processed Thorium with offshore data masked out (ppm)

	\|-		\|-
	\| Thorium.grd \|\| Processed Thorium (ppm)		\| • Thorium.grd \|\| Processed Thorium (ppm)
	\|-		\|-
	\| Total Count masked.grd \|\| Processed Total Count with offshore data masked out (cps)		\| • Total Count masked.grd \|\| Processed Total Count with offshore data masked out (cps)
	\|-		\|-
	\| Total Count.grd \|\| Processed Total Count (cps)		\| • Total Count.grd \|\| Processed Total Count (cps)
	\|-		\|-
	\| Uranium masked.grd \|\| Processed Uranium with offshore data masked out (ppm)		\| • Uranium masked.grd \|\| Processed Uranium with offshore data masked out (ppm)
	\|-		\|-
	\| Uranium.grd \|\| Processed Uranium (ppm)		\| • Uranium.grd \|\| Processed Uranium (ppm)
	\|-		\|-
	\| '''Other Grid'''		\| '''Other Grid'''
	\|-		\|-
	\| Terrain.grd \|\| Digital Terrain Model (m)		\| • Terrain.grd \|\| Digital Terrain Model (m)
	\|}		\|}