Tropospheric ducting - Revision history

TimVK4YEH: corrected error

2011-01-06T21:41:45Z

corrected error

← Older revision		Revision as of 14:41, 6 January 2011
Line 3:		Line 3:
	== Basics ==		== Basics ==

	The [http://en.wikipedia.org/wiki/Troposphere troposphere] is the layer of atmosphere closest to earth. It is approximately 10km deep on average, but can extend to ~~20lm~~ in tropical areas.		The [http://en.wikipedia.org/wiki/Troposphere troposphere] is the layer of atmosphere closest to earth. It is approximately 10km deep on average, but can extend to 20km in tropical areas.

	[[Image:Vk4yeh_atmosphere.jpg]]		[[Image:Vk4yeh_atmosphere.jpg]]

Carlb: /* Links: */

2009-04-09T01:36:48Z

Links:

← Older revision		Revision as of 18:36, 8 April 2009
Line 16:		Line 16:

	== Links: ==		== Links: ==
			* [http://www.dxinfocentre.com/tropo_nwe.html Worldwide] ducting forecast from DXinfocentre.

	~~[http://www.dxinfocentre.com/tropo_nwe.html Worldwide] ducting forecast from DXinfocentre.~~
			{{propagation}}

TimVK4YEH: added link to TEP

2008-08-15T07:58:31Z

added link to TEP

← Older revision		Revision as of 00:58, 15 August 2008
Line 1:		Line 1:
	Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]], [[Aurora]]		Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]], [[Aurora]], [[Trans-Equatorial Propagation]]

	== Basics ==		== Basics ==

TimVK4YEH at 07:30, 15 August 2008

2008-08-15T07:30:31Z

← Older revision		Revision as of 00:30, 15 August 2008
Line 1:		Line 1:
	Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]], [[~~Aroura~~]]		Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]], [[Aurora]]

	== Basics ==		== Basics ==

TimVK4YEH at 07:30, 15 August 2008

2008-08-15T07:30:10Z

← Older revision		Revision as of 00:30, 15 August 2008
Line 1:		Line 1:
	Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]]		Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]], [[Aroura]]

	== Basics ==		== Basics ==

TimVK4YEH: added link to lightning scatter

2008-08-15T07:29:51Z

added link to lightning scatter

← Older revision		Revision as of 00:29, 15 August 2008
Line 1:		Line 1:
	Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]],		Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]], [[Lightning scatter]]

	== Basics ==		== Basics ==

TimVK4YEH: added link to meteor scatter

2008-08-12T09:31:13Z

added link to meteor scatter

← Older revision		Revision as of 02:31, 12 August 2008
Line 1:		Line 1:
	Related wiki pages: [[Propagation]], [[Bands]],		Related wiki pages: [[Propagation]], [[Bands]], [[Meteor scatter]],

	== Basics ==		== Basics ==

TimVK4YEH: at last - tropoducting pic renders properly!

2008-07-03T23:34:46Z

at last - tropoducting pic renders properly!

← Older revision		Revision as of 16:34, 3 July 2008
Line 11:		Line 11:
	The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.		The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.

			[[Image:Vk4yeh_tropoducting.jpg\|600px]]

	When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.		When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.

TimVK4YEH: /* Basics */

2008-07-03T23:10:12Z

Basics

← Older revision		Revision as of 16:10, 3 July 2008
Line 11:		Line 11:
	The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.		The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.

	~~[[Image:Vk4yeh_tropoducting.jpg]]~~

	When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.		When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.

TimVK4YEH: ?error in tropoducting pic

2008-07-03T23:09:36Z

?error in tropoducting pic

← Older revision		Revision as of 16:09, 3 July 2008
Line 4:		Line 4:

	The [http://en.wikipedia.org/wiki/Troposphere troposphere] is the layer of atmosphere closest to earth. It is approximately 10km deep on average, but can extend to 20lm in tropical areas.		The [http://en.wikipedia.org/wiki/Troposphere troposphere] is the layer of atmosphere closest to earth. It is approximately 10km deep on average, but can extend to 20lm in tropical areas.

			[[Image:Vk4yeh_atmosphere.jpg]]

	Tropospheric propagation occurs when signals are reflected scattered or refracted in the troposphere. "Ducting" effects occur primarily because of [http://en.wikipedia.org/wiki/Temperature_inversion temperature inversions] at a height of between 500m and 1500m, and occasionally up to 3000m. Such inversions are not caused by local "weather" or terrain, but rather by climatic conditions such as [http://en.wikipedia.org/wiki/Weather_front frontal boundaries]. Temperature inversions are usually layers rather than sharp lines separating regions of different temperature.		Tropospheric propagation occurs when signals are reflected scattered or refracted in the troposphere. "Ducting" effects occur primarily because of [http://en.wikipedia.org/wiki/Temperature_inversion temperature inversions] at a height of between 500m and 1500m, and occasionally up to 3000m. Such inversions are not caused by local "weather" or terrain, but rather by climatic conditions such as [http://en.wikipedia.org/wiki/Weather_front frontal boundaries]. Temperature inversions are usually layers rather than sharp lines separating regions of different temperature.
Line 9:		Line 11:
	The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.		The thickness of the inversion layer affects the LUF (Lowest usable frequency) - thinner layers only propagate higher frequencies such as microwaves, thicker layers can be used into lower frequency regions of the spectrum. [http://www.dxinfocentre.com/propagation/luf.htm This table] shows inversion thickness and LUF data.

	When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.		[[Image:Vk4yeh_tropoducting.jpg]]

			When ducting occurs, signals travel along and within the inversion layer, reflected off its boundaries.

	== Links: ==		== Links: ==

	[http://www.dxinfocentre.com/tropo_nwe.html Worldwide] ducting forecast from DXinfocentre.		[http://www.dxinfocentre.com/tropo_nwe.html Worldwide] ducting forecast from DXinfocentre.