Weather Satellite Imaging
What is Satellite Imaging?
Satellite Imaging is the collection and interpretation of data and images by high tech satellites that orbit our Earth.
This page looks at Weather Satellite Imaging, a vital addition to our Environment & Weather monitoring capabilities.
Principals of Operation
Currently, there are two types of Weather Satellites, capable of collecting data and images.
POLAR ORBITING (APT & HRPT)
GEOSTATIONARY (WEFAX & PDUS)
POLAR ORBITING SATELLITES
Polar Orbiting Satellites have been above our sky's since 1960 when the very first satellite of it's kind was launched.
This satellite was called TIROS-1 and today, some forty two years later, current satellites are still launched in the TIROS configuration. The name Polar Orbiting is derived from the Orbit of the satellite. Each revolution by the satellite ends and begins near the two Poles. Currently, NOAA the US Government department charged with operating the US satellites has three active Satellites called NOAA 12, 14 &15. A fourth satellite NOAA 16 was launched in 2000 and is currently undergoing in orbit checks before being released for operation. These satellites have onboard thermal imaging, along with infrared and visible cameras. They can measure temperatures in our sea, our air and on land and can measure cloud thickness. Images are transmitted back to Earth in real time where ground stations can receive these images and data using relatively inexpensive equipment. Further information on NOAA and it's scientific research program can be found by visiting the NPOESS web site. In addition to the US Satellites, there are many operational from Russia and China.
Below is an example of an image received from NOAA 14 during the Summer of 1998. This is a colour image made up from an infrared image and a visible image. The two images are combined to give a FALSE colour image. Here we see a cloud free UK. The second image is of the UK and Europe and was taken by the Satellites on board infrared camera. The South East Tip of Greenland can be seen in the upper left corner of the image. This image was received on the 8th of October 2000
GEOSTATIONARY SATELLITES
As there name suggests, these Satellites appear to be fixed in one place 24 hours a day. This is due to their height above our ground which is some 36,000km and their velocity which matches our Earth's. These Satellites are injected into what's called a Geostationary orbit and onboard stabilizers prevent the Satellite from spinning. This location allows accurate data to be collected on one specific area of our Planet. A series of Satellites run by the US Government in association with NASA currently collect data and images from the US. These are known as GOES (Geostationary Operational Environmental Satellite). One of it's primary missions is to monitor the Atlantic Ocean for Hurricanes. These Satellites give Meteorologists invaluable information when predicting the possible danger areas when a Hurricane is heading for populated Area's.
The two images below are typical examples of images produced by GOES 8. The first one shows the overall capture area. This is where the Hurricanes are first detected and then constantly monitored.
The second Image is of an actual Hurricane. This was Hurricane Mitch which lasted from 22nd October through to November 4th 1998.
Full details of this Storm and others can be found by visiting the OSEI Web Site
An up to the minute Image from GOES can be viewed by linking here.
Image above courtesy of the GOES Web site at www.goes.noaa.gov
Image above courtesy of the OSEI Web site at www.osei.noaa.gov
EUROPEAN SATELLITES
Europe has a strong Weather Satellite Presence in the form of METEOSAT, a series of Geostationary Satellites run by EUMETSAT in Germany. Meteosat Satellites occupy an Equatorial Geostationary orbit. This location is ideal for collecting data from Iceland to Southern Africa. An example of an image taken by Meteosat (MET7) can be seen below. This is a Colour Visible Image with Country overlays.
"copyright © 2001 EUMETSAT" "copyright © 2001 EUMETSAT"
Probably one of the best images of our Planet is the so called "FULL DISC" image. The image Top right was taken by Met7 on April 4th 2001. The Area around the Northern part of Africa shows up as black due to the difference in temperature between Land and Sea.
Top of Page**This page was put together as part of an assignment for an Open University course taken in 2001. **
