Comments on: Measuring the height of contrails http://contrailscience.com/measuring-the-height-of-contrails/ The Science and Pseudoscience of Contrails and Chemtrails Sat, 04 Feb 2012 15:04:06 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Alexeyhttp://contrailscience.com/measuring-the-height-of-contrails/comment-page-1/#comment-56353 Alexey Tue, 11 Jan 2011 23:40:28 +0000 http://contrailscience.com/measuring-the-height-of-contrails/#comment-56353 Last Sunday (9 January 2011) was a very fine day here. I watched many high flying jet in the clear sky, but none of them left a persistent contrail. Later I checked the satellite photos, the nearest contrailed area was across the North sea (http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Cabauw.2011009.terra.250m). It run along the Dutch and Belgian coast in a strip of about 400 km long but less than 40 km wide. In its middle part, there was a ladder-like grid, casting a distinct shadow on the sea surface. The superposition of ladder pattern on its shadow by sliding the picture relative itself gives a very good match. The same operation also superimposes the other contrails in the strip onto their shadows. This means that all contrails in this area are roughly at the same altitude. [img]http://contrailscience.com/wp-content/uploads/Dutch_contrails_2011009.png[/img] I have applied the revised method to measure the height of contrails in this area. [img]http://contrailscience.com/wp-content/uploads/Picture 5-1.png[/img] A the time of the photo, 11:05 UTC, the sun azimuth and altitude were 170 deg and 16 deg, respectively. The satellite azimuth, 285 deg, is deduced from the direction of parallel lines on the sea surface, the artifact of composite image assembly. The distance between the actual location of contrail and its shadow is 31.3 km, thus the contrail height is 31.3 tan(16 deg) = 9 km = 30k feet. The distance between the actual location of contrail and its image is about 3.8 km, giving the elevation angle of satellite: arctan(9/3.8) = 67 deg. The ladder-like grid was probably created by a number of morning flights across the strip (between the continental Europe and the UK and America) and along the strip (between Scandinavia and Iberia). It did not stay there for long. Less than two hours later, in the Aqua photo taken at 12:55 UST (http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Cabauw.2011009.aqua.250m), this area was clear. The contrails were blown inland by wind and/or dissipated. Last Sunday (9 January 2011) was a very fine day here. I watched many high flying jet in the clear sky, but none of them left a persistent contrail. Later I checked the satellite photos, the nearest contrailed area was across the North sea
(http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Cabauw.2011009.terra.250m).
It run along the Dutch and Belgian coast in a strip of about 400 km long but less than 40 km wide. In its middle part, there was a ladder-like grid, casting a distinct shadow on the sea surface. The superposition of ladder pattern on its shadow by sliding the picture relative itself gives a very good match. The same operation also superimposes the other contrails in the strip onto their shadows. This means that all contrails in this area are roughly at the same altitude.

I have applied the revised method to measure the height of contrails in this area.

[img]http://contrailscience.com/wp-content/uploads/Picture 5-1.png[/img]
A the time of the photo, 11:05 UTC, the sun azimuth and altitude were 170 deg and 16 deg, respectively. The satellite azimuth, 285 deg, is deduced from the direction of parallel lines on the sea surface, the artifact of composite image assembly. The distance between the actual location of contrail and its shadow is 31.3 km, thus the contrail height is 31.3 tan(16 deg) = 9 km = 30k feet. The distance between the actual location of contrail and its image is about 3.8 km, giving the elevation angle of satellite: arctan(9/3.8) = 67 deg.

The ladder-like grid was probably created by a number of morning flights across the strip (between the continental Europe and the UK and America) and along the strip (between Scandinavia and Iberia). It did not stay there for long. Less than two hours later, in the Aqua photo taken at 12:55 UST
(http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Cabauw.2011009.aqua.250m),
this area was clear. The contrails were blown inland by wind and/or dissipated.

]]> By: Alexeyhttp://contrailscience.com/measuring-the-height-of-contrails/comment-page-1/#comment-56314 Alexey Tue, 11 Jan 2011 09:11:35 +0000 http://contrailscience.com/measuring-the-height-of-contrails/#comment-56314 Yes, I mean the elevation (el) angle, also called the altitude, according to your link. I have encountered the latter first, looking for a proper English term. Surprisingly, the elevation angle of the satellite is quite low for some areas of the composite satellite photographs, projecting contrails to the ground ten miles away from their actual locations. Yes, I mean the elevation (el) angle, also called the altitude, according to your link. I have encountered the latter first, looking for a proper English term.
Surprisingly, the elevation angle of the satellite is quite low for some areas of the composite satellite photographs, projecting contrails to the ground ten miles away from their actual locations.

]]> By: Uncinushttp://contrailscience.com/measuring-the-height-of-contrails/comment-page-1/#comment-56288 Uncinus Mon, 10 Jan 2011 23:25:44 +0000 http://contrailscience.com/measuring-the-height-of-contrails/#comment-56288 So maybe you mean "elevation", not "azimuth"? http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci838808,00.html <img src="http://searchcio-midmarket.techtarget.com/WhatIs/images/az-el.gif" alt="" /> So maybe you mean “elevation”, not “azimuth”?
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci838808,00.html

]]> By: Uncinushttp://contrailscience.com/measuring-the-height-of-contrails/comment-page-1/#comment-56287 Uncinus Mon, 10 Jan 2011 23:23:52 +0000 http://contrailscience.com/measuring-the-height-of-contrails/#comment-56287 Isn't "azimuth" correct, as you are referencing an angular measurement? Isn’t “azimuth” correct, as you are referencing an angular measurement?

]]> By: Alexeyhttp://contrailscience.com/measuring-the-height-of-contrails/comment-page-1/#comment-56286 Alexey Mon, 10 Jan 2011 22:56:30 +0000 http://contrailscience.com/measuring-the-height-of-contrails/#comment-56286 In the last paragraph of the previous comment, instead of "satellite azimuth" read "satellite altitude". In the last paragraph of the previous comment, instead of “satellite azimuth” read “satellite altitude”.

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