Why is short-wave infrared portion of electromagnetic spectrum so sensitive to fire?Counting animals using near infrared imagery from a droneBest Landsat-5 TM band combination for detecting fire scarsWhy does Landsat 8 panchromatic band NOT include the infrared?Why are Landsat-8 derived NDVI values higher than SAVI values?Why can't get correct RGB img of Landsat 8 using np.dstackWhy Sentinel-2 bands have different spatial resolutionWhy does my rainbow airplane stripes appearing on Sentinel 2 image?Convertion of spectral indices formulas from Landsat to SentinelWhy is satellite imagery data delivered as signed 16 bit integers?InSAR processing: why can't we just compute distances directly from time delays?
Not using 's' for he/she/it
Why did the Mercure fail?
Why Shazam when there is already Superman?
What does chmod -u do?
Open a doc from terminal, but not by its name
The IT department bottlenecks progress. How should I handle this?
Did arcade monitors have same pixel aspect ratio as TV sets?
What is the evidence for the "tyranny of the majority problem" in a direct democracy context?
Why did the EU agree to delay the Brexit deadline?
Electoral considerations aside, what are potential benefits, for the US, of policy changes proposed by the tweet recognizing Golan annexation?
Does an advisor owe his/her student anything? Will an advisor keep a PhD student only out of pity?
How can I block email signup overlays or javascript popups in Safari?
Added a new user on Ubuntu, set password not working?
How can "mimic phobia" be cured or prevented?
Is it possible to have a strip of cold climate in the middle of a planet?
A social experiment. What is the worst that can happen?
How do you make your own symbol when Detexify fails?
How to implement a feedback to keep the DC gain at zero for this conceptual passive filter?
If a character has darkvision, can they see through an area of nonmagical darkness filled with lightly obscuring gas?
Melting point of aspirin, contradicting sources
L1 and Ln cache: when are they written?
What percentage of fillings performed today are done with mercury amalgam?
Can Legal Documents Be Siged In Non-Standard Pen Colors?
250 Floor Tower
Why is short-wave infrared portion of electromagnetic spectrum so sensitive to fire?
Counting animals using near infrared imagery from a droneBest Landsat-5 TM band combination for detecting fire scarsWhy does Landsat 8 panchromatic band NOT include the infrared?Why are Landsat-8 derived NDVI values higher than SAVI values?Why can't get correct RGB img of Landsat 8 using np.dstackWhy Sentinel-2 bands have different spatial resolutionWhy does my rainbow airplane stripes appearing on Sentinel 2 image?Convertion of spectral indices formulas from Landsat to SentinelWhy is satellite imagery data delivered as signed 16 bit integers?InSAR processing: why can't we just compute distances directly from time delays?
After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in no way associated to thermal IR.
What property does fire have, that makes is visible with shortwave infrared?
remote-sensing copernicus
add a comment |
After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in no way associated to thermal IR.
What property does fire have, that makes is visible with shortwave infrared?
remote-sensing copernicus
1
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
2
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday
add a comment |
After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in no way associated to thermal IR.
What property does fire have, that makes is visible with shortwave infrared?
remote-sensing copernicus
After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in no way associated to thermal IR.
What property does fire have, that makes is visible with shortwave infrared?
remote-sensing copernicus
remote-sensing copernicus
edited yesterday
PolyGeo♦
53.7k1781244
53.7k1781244
asked yesterday
Robert BuckleyRobert Buckley
4,8601255115
4,8601255115
1
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
2
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday
add a comment |
1
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
2
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday
1
1
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
2
2
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday
add a comment |
2 Answers
2
active
oldest
votes
According to Wien's law, the wavelength of the peak emission depends on the temperature.
wavelength_of_peak = 2.898*10^(-3)/T
where T is the temperature in degree Kelvin. So the wavelength of the peak emission decrease when the temperature increases.
For the temparature of the surface of the Earth, you are around 300 K, so the peak is about 10 micrometer (the so called thermal infrared). In case of fire, the temperature is more like 1200 K, so the peak wavelength is close to 2.4, which correspond to the second SWIR band of Landsat.
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
add a comment |
First, I would reword the question to Why is fire "visible" in the short-wave infrared portion of electromagnetic spectrum ?
Second, I would like to add my 2 cents to @radouxju answer. These 2 examples could make the explanation clearer:
A piece of metal heated by a blow torch first becomes "red hot" as the very longest visible wavelengths appear red, then becomes more orange-red as the temperature is increased, and at very high temperatures would be described as "white hot" as shorter and shorter wavelengths come to predominate the black body emission spectrum. Before it had even reached the red hot temperature, the thermal emission was mainly at longer infrared wavelengths, which are not visible; nevertheless, that radiation could be felt as it warms one's nearby skin.
A wood fire at 1500 K puts out peak radiation at about 2000 nm. 98% of its radiation is at wavelengths longer than 1000 nm, and only a tiny proportion at visible wavelengths (390–700 nm). Consequently, a campfire can keep one warm but is a poor source of visible light.
So, the spectrum is not sensitive, the temperature is related to the electromagnetic radiation emission at a certain wavelength range. A high temperature like the sun (~5700K) will emit a peak around 500nm (green), but it is also emitting in the UV, visible and IR range. On the other side, fire or wood fire (as the example) will have a peak at ~2200nm, having most of the emitted radiation outside the visible range, that is, in the SWIR range.
source: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
Your Answer
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "79"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fgis.stackexchange.com%2fquestions%2f316341%2fwhy-is-short-wave-infrared-portion-of-electromagnetic-spectrum-so-sensitive-to-f%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
According to Wien's law, the wavelength of the peak emission depends on the temperature.
wavelength_of_peak = 2.898*10^(-3)/T
where T is the temperature in degree Kelvin. So the wavelength of the peak emission decrease when the temperature increases.
For the temparature of the surface of the Earth, you are around 300 K, so the peak is about 10 micrometer (the so called thermal infrared). In case of fire, the temperature is more like 1200 K, so the peak wavelength is close to 2.4, which correspond to the second SWIR band of Landsat.
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
add a comment |
According to Wien's law, the wavelength of the peak emission depends on the temperature.
wavelength_of_peak = 2.898*10^(-3)/T
where T is the temperature in degree Kelvin. So the wavelength of the peak emission decrease when the temperature increases.
For the temparature of the surface of the Earth, you are around 300 K, so the peak is about 10 micrometer (the so called thermal infrared). In case of fire, the temperature is more like 1200 K, so the peak wavelength is close to 2.4, which correspond to the second SWIR band of Landsat.
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
add a comment |
According to Wien's law, the wavelength of the peak emission depends on the temperature.
wavelength_of_peak = 2.898*10^(-3)/T
where T is the temperature in degree Kelvin. So the wavelength of the peak emission decrease when the temperature increases.
For the temparature of the surface of the Earth, you are around 300 K, so the peak is about 10 micrometer (the so called thermal infrared). In case of fire, the temperature is more like 1200 K, so the peak wavelength is close to 2.4, which correspond to the second SWIR band of Landsat.
According to Wien's law, the wavelength of the peak emission depends on the temperature.
wavelength_of_peak = 2.898*10^(-3)/T
where T is the temperature in degree Kelvin. So the wavelength of the peak emission decrease when the temperature increases.
For the temparature of the surface of the Earth, you are around 300 K, so the peak is about 10 micrometer (the so called thermal infrared). In case of fire, the temperature is more like 1200 K, so the peak wavelength is close to 2.4, which correspond to the second SWIR band of Landsat.
edited yesterday
answered yesterday
radouxjuradouxju
41.2k144120
41.2k144120
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
add a comment |
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
Wien's Law is correct so far as it goes, but you should preface that with the assumption that the radiation given off follows blackbody radiation.
– MaxW
yesterday
add a comment |
First, I would reword the question to Why is fire "visible" in the short-wave infrared portion of electromagnetic spectrum ?
Second, I would like to add my 2 cents to @radouxju answer. These 2 examples could make the explanation clearer:
A piece of metal heated by a blow torch first becomes "red hot" as the very longest visible wavelengths appear red, then becomes more orange-red as the temperature is increased, and at very high temperatures would be described as "white hot" as shorter and shorter wavelengths come to predominate the black body emission spectrum. Before it had even reached the red hot temperature, the thermal emission was mainly at longer infrared wavelengths, which are not visible; nevertheless, that radiation could be felt as it warms one's nearby skin.
A wood fire at 1500 K puts out peak radiation at about 2000 nm. 98% of its radiation is at wavelengths longer than 1000 nm, and only a tiny proportion at visible wavelengths (390–700 nm). Consequently, a campfire can keep one warm but is a poor source of visible light.
So, the spectrum is not sensitive, the temperature is related to the electromagnetic radiation emission at a certain wavelength range. A high temperature like the sun (~5700K) will emit a peak around 500nm (green), but it is also emitting in the UV, visible and IR range. On the other side, fire or wood fire (as the example) will have a peak at ~2200nm, having most of the emitted radiation outside the visible range, that is, in the SWIR range.
source: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
First, I would reword the question to Why is fire "visible" in the short-wave infrared portion of electromagnetic spectrum ?
Second, I would like to add my 2 cents to @radouxju answer. These 2 examples could make the explanation clearer:
A piece of metal heated by a blow torch first becomes "red hot" as the very longest visible wavelengths appear red, then becomes more orange-red as the temperature is increased, and at very high temperatures would be described as "white hot" as shorter and shorter wavelengths come to predominate the black body emission spectrum. Before it had even reached the red hot temperature, the thermal emission was mainly at longer infrared wavelengths, which are not visible; nevertheless, that radiation could be felt as it warms one's nearby skin.
A wood fire at 1500 K puts out peak radiation at about 2000 nm. 98% of its radiation is at wavelengths longer than 1000 nm, and only a tiny proportion at visible wavelengths (390–700 nm). Consequently, a campfire can keep one warm but is a poor source of visible light.
So, the spectrum is not sensitive, the temperature is related to the electromagnetic radiation emission at a certain wavelength range. A high temperature like the sun (~5700K) will emit a peak around 500nm (green), but it is also emitting in the UV, visible and IR range. On the other side, fire or wood fire (as the example) will have a peak at ~2200nm, having most of the emitted radiation outside the visible range, that is, in the SWIR range.
source: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
First, I would reword the question to Why is fire "visible" in the short-wave infrared portion of electromagnetic spectrum ?
Second, I would like to add my 2 cents to @radouxju answer. These 2 examples could make the explanation clearer:
A piece of metal heated by a blow torch first becomes "red hot" as the very longest visible wavelengths appear red, then becomes more orange-red as the temperature is increased, and at very high temperatures would be described as "white hot" as shorter and shorter wavelengths come to predominate the black body emission spectrum. Before it had even reached the red hot temperature, the thermal emission was mainly at longer infrared wavelengths, which are not visible; nevertheless, that radiation could be felt as it warms one's nearby skin.
A wood fire at 1500 K puts out peak radiation at about 2000 nm. 98% of its radiation is at wavelengths longer than 1000 nm, and only a tiny proportion at visible wavelengths (390–700 nm). Consequently, a campfire can keep one warm but is a poor source of visible light.
So, the spectrum is not sensitive, the temperature is related to the electromagnetic radiation emission at a certain wavelength range. A high temperature like the sun (~5700K) will emit a peak around 500nm (green), but it is also emitting in the UV, visible and IR range. On the other side, fire or wood fire (as the example) will have a peak at ~2200nm, having most of the emitted radiation outside the visible range, that is, in the SWIR range.
source: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
First, I would reword the question to Why is fire "visible" in the short-wave infrared portion of electromagnetic spectrum ?
Second, I would like to add my 2 cents to @radouxju answer. These 2 examples could make the explanation clearer:
A piece of metal heated by a blow torch first becomes "red hot" as the very longest visible wavelengths appear red, then becomes more orange-red as the temperature is increased, and at very high temperatures would be described as "white hot" as shorter and shorter wavelengths come to predominate the black body emission spectrum. Before it had even reached the red hot temperature, the thermal emission was mainly at longer infrared wavelengths, which are not visible; nevertheless, that radiation could be felt as it warms one's nearby skin.
A wood fire at 1500 K puts out peak radiation at about 2000 nm. 98% of its radiation is at wavelengths longer than 1000 nm, and only a tiny proportion at visible wavelengths (390–700 nm). Consequently, a campfire can keep one warm but is a poor source of visible light.
So, the spectrum is not sensitive, the temperature is related to the electromagnetic radiation emission at a certain wavelength range. A high temperature like the sun (~5700K) will emit a peak around 500nm (green), but it is also emitting in the UV, visible and IR range. On the other side, fire or wood fire (as the example) will have a peak at ~2200nm, having most of the emitted radiation outside the visible range, that is, in the SWIR range.
source: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered yesterday
gustavovelascohgustavovelascoh
1413
1413
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
gustavovelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
Thanks for contributing an answer to Geographic Information Systems Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fgis.stackexchange.com%2fquestions%2f316341%2fwhy-is-short-wave-infrared-portion-of-electromagnetic-spectrum-so-sensitive-to-f%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
1
This sounds like a question more on-topic at the Earth Science Stack Exchange than here.
– PolyGeo♦
yesterday
2
@PolyGeo this is a question about spectral signature, so it also belongs here as long as this site hosts remote sensing questions.
– radouxju
yesterday