Microwaves guard weather forecasts, or what a scatterometer
It's no secret that the wind blows only because the trees are swaying. However, the guys from NASA JPL (and not only them) decided to go further than the hero of the famous comedy “Business People”, and successfully study the wind directly from space. How? I will tell about it under a cat.
According to personal tradition, I attach a video that I translated and voiced specifically for this note. Everything is explained in it as simply as possible and without unnecessary details.
A few words about terminology: there are two almost equivalent concepts: reflectometry and scatterometry . However, I propose to call the study of the Earth's surface from space precisely scatterometry, in order to avoid confusion during translations and adaptations.
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Speaking in simple language, scatterometry is a method of measuring the size and shape of an object (more often, the relief of a surface) based on how the object reflects and diffuses light. Consequently, the scatterometer is a microwave radar that “fires” the surface with beams of light and tries to catch the reflected rays.
Scatterometers can work both from space, for example, by clinging to a satellite, and during air travel within the earth’s atmosphere, comfortably sitting under the belly of an airplane. Microwaves are used for scanning, therefore NASA employees jokingly call the devices “microwaves”.
It is worth noting that the devices are long and carefully calibrated: errors in the measurement of reflected-scattered rays are very significant. That is why NASA plans to use the already-running scatterometers for accelerating the calibration process of its latest device: the RapidScat.
RapidScat is the most advanced and technologically advanced scatterometer, which is scheduled to launch at the end of this year. SpaceX Dragon will deliver the device to the ISS, where it will begin to perform its main function - scanning the surface of oks and seas. There are no special requirements for the mission, but NASA has set several goals for its “microwave”.
RapidScat attached to the International Space Station
Objectives of RapidScat:
1) Create a new platform for constellation scatterometers
RapidScat should provide a new calibration platform that will improve the stability and accuracy of the data received by the rest of the scatterometers operating on Earth orbit.
2) To investigate the daily and semi-daily wind cycles in the ocean, as well as the evaporation of water from the surface of the Earth.
3) Provide data for forecasting weather and sea storms, as well as data for the introduction of time cycles in space.
In addition to RapidScat, the whole constellation of scatterometers is concerned with the study of winds: Seasat Scatterometer (SASS), launched in 1978, launched by the European Space Agency in 1991, European Remote-Sensing Satellite ERS-1, armed with Advanced Microwave Instrument (AMI) equipment, and also launched after first ERS-2 (1995). In 1996, NASA launches the first NASA Scatterometer (NSCAT).
The first scanning scatterometer launched by NASA, also known as ' SeaWinds ', went to work in 1999. In 2002, NASDA ADEOS-2 followed it. Another launch took place in 2006, when the European Space Agency sent ASCAT into orbit.
In addition, the Indian Space Agency launched its own spacecraft in 2009.
The intersection of the trajectories of scatterometers and ISS
Thus, at the end of this year, NASA expects to begin to solve the problems of meteorology and calibration of the entire constellation of vehicles.
The importance of such studies is due to the fact that we still call some physical phenomena "riddles of nature."
Data obtained from ocean scatterometers will help scientists better explore the interaction of the atmosphere and the ocean, ocean circulation, and their effect on weather conditions and global climate.
These data can also be used to study unusual weather events, such as El Niño , the long-term effects of deforestation, and changes in ice masses around the polar regions. All these phenomena play a central role in regulating the global climate.
The following materials were used when writing the note:
About Scatteromerty by NASA JPL
Ocean Wind program by NASA JPL
Scatterometer on Wikipedia
PS It would be nice to add an article about scatterometers to Wikipedia in Russian: the method itself, and the programs deserve more detailed attention.
According to personal tradition, I attach a video that I translated and voiced specifically for this note. Everything is explained in it as simply as possible and without unnecessary details.
A few words about terminology: there are two almost equivalent concepts: reflectometry and scatterometry . However, I propose to call the study of the Earth's surface from space precisely scatterometry, in order to avoid confusion during translations and adaptations.
')
Speaking in simple language, scatterometry is a method of measuring the size and shape of an object (more often, the relief of a surface) based on how the object reflects and diffuses light. Consequently, the scatterometer is a microwave radar that “fires” the surface with beams of light and tries to catch the reflected rays.
Scatterometers can work both from space, for example, by clinging to a satellite, and during air travel within the earth’s atmosphere, comfortably sitting under the belly of an airplane. Microwaves are used for scanning, therefore NASA employees jokingly call the devices “microwaves”.
It is worth noting that the devices are long and carefully calibrated: errors in the measurement of reflected-scattered rays are very significant. That is why NASA plans to use the already-running scatterometers for accelerating the calibration process of its latest device: the RapidScat.
RapidScat is the most advanced and technologically advanced scatterometer, which is scheduled to launch at the end of this year. SpaceX Dragon will deliver the device to the ISS, where it will begin to perform its main function - scanning the surface of oks and seas. There are no special requirements for the mission, but NASA has set several goals for its “microwave”.
RapidScat attached to the International Space Station
Objectives of RapidScat:
1) Create a new platform for constellation scatterometers
RapidScat should provide a new calibration platform that will improve the stability and accuracy of the data received by the rest of the scatterometers operating on Earth orbit.
2) To investigate the daily and semi-daily wind cycles in the ocean, as well as the evaporation of water from the surface of the Earth.
3) Provide data for forecasting weather and sea storms, as well as data for the introduction of time cycles in space.
In addition to RapidScat, the whole constellation of scatterometers is concerned with the study of winds: Seasat Scatterometer (SASS), launched in 1978, launched by the European Space Agency in 1991, European Remote-Sensing Satellite ERS-1, armed with Advanced Microwave Instrument (AMI) equipment, and also launched after first ERS-2 (1995). In 1996, NASA launches the first NASA Scatterometer (NSCAT).
The first scanning scatterometer launched by NASA, also known as ' SeaWinds ', went to work in 1999. In 2002, NASDA ADEOS-2 followed it. Another launch took place in 2006, when the European Space Agency sent ASCAT into orbit.
In addition, the Indian Space Agency launched its own spacecraft in 2009.
The intersection of the trajectories of scatterometers and ISS
Thus, at the end of this year, NASA expects to begin to solve the problems of meteorology and calibration of the entire constellation of vehicles.
The importance of such studies is due to the fact that we still call some physical phenomena "riddles of nature."
Data obtained from ocean scatterometers will help scientists better explore the interaction of the atmosphere and the ocean, ocean circulation, and their effect on weather conditions and global climate.
These data can also be used to study unusual weather events, such as El Niño , the long-term effects of deforestation, and changes in ice masses around the polar regions. All these phenomena play a central role in regulating the global climate.
The following materials were used when writing the note:
About Scatteromerty by NASA JPL
Ocean Wind program by NASA JPL
Scatterometer on Wikipedia
PS It would be nice to add an article about scatterometers to Wikipedia in Russian: the method itself, and the programs deserve more detailed attention.
Source: https://habr.com/ru/post/223419/
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