Short Event Description: Participants will use remote sensing imagery, data and computational process skills to complete tasks related to climate change processes in the Earth system.
What is the difference between active and passive sensing?
Re: Remote Sensing C
Posted: September 6th, 2016, 9:52 pm
by zyzzyva980
bhavjain wrote:Short Event Description: Participants will use remote sensing imagery, data and computational process skills to complete tasks related to climate change processes in the Earth system.
What is the difference between active and passive sensing?
This is a great question to start with because it will be on literally every Remote Sensing test you take this year. Know the answer to this question.
Re: Remote Sensing C
Posted: September 7th, 2016, 5:07 am
by EastStroudsburg13
zyzzyva980 wrote:
bhavjain wrote:Short Event Description: Participants will use remote sensing imagery, data and computational process skills to complete tasks related to climate change processes in the Earth system.
What is the difference between active and passive sensing?
This is a great question to start with because it will be on literally every Remote Sensing test you take this year. Know the answer to this question.
Confirmed. I don't think I ever had one without it.
Re: Remote Sensing C
Posted: September 7th, 2016, 5:28 am
by Unome
Active - the sensor emits radiation and detects its reflection. Passive - the sensor detects the reflection of radiation from an outside source (e.g. the sun).
Using the term scattering in your answer, why is the sky blue?
Re: Remote Sensing C
Posted: November 20th, 2016, 6:19 am
by Unome
The smaller particles in the air disperse sunlight via Rayleigh scattering, which causes light to be visible from all directions. Since Rayleigh scattering is more effective at shorter wavelengths, blue light is scattered more than longer colors.
Re: Remote Sensing C
Posted: December 22nd, 2016, 2:41 pm
by hearthstone224
Restarting this x2!
This isn't really much of a question you might see on a test, but I'm still curious.
What does blackbody radiation and blackbodies have to do with remote sensing?
I've read through the rules and tried to define the terms.. Most of the first part have something to do with blackbody radiation (Planck's function, Wies' law, so on)
Re: Remote Sensing C
Posted: December 22nd, 2016, 3:51 pm
by jonboyage
Blackbody radiation is when a blackbody emits radiation when at different temperatures. When a blackbody has a certain temperature, it has a specific wavelength at which it emits the most of its radiation (peak emission). If we treat the Earth's surface as a blackbody, then we can measure the temperature of a surface using the radiation emitted. For example, if the surface is 300 kelvin, then the peak emission is about 10 micrometers. This is why many satellites are tuned to be able to detect 10 micrometer radiation when observing the Earth. Other satellites, such as Terra, which have the instrument MODIS, are able to detect fire hot spots by measuring wavelengths of about 3 micrometers, representing temperatures of approximately 1000 kelvin.
Re: Remote Sensing C
Posted: December 27th, 2016, 10:07 am
by hearthstone224
Oh, so basically the blackbody radiation is used to find the surface temperature of something?
And can someone define blackbody for me? I got it as "a physical body that absorbs all EM radiation regardless of frequency or angle of incidence."