posted on Oct, 6 2008 @ 12:58 AM
Since the 1960s, the capability to view Earth's cloud patterns from space has been made possible from two main types of environmental satellites,
geostationary Earth-orbiting and low Earth-orbiting satellites. At least five geostationary satellites positioned around the equator are capable of
providing depictions of global weather patterns, updated every hour. From their vantage point 36,000 km above the equator, the sensors onboard
geostationary satellites can't quite 'see'the very high latitudes near the north and south poles. Since their orbit flies over the high latitude
regions over the north and south poles typically every 90 minutes, low Earth-orbiting satellite imagery is well-suited to complement the geostationary
imagery and thereby provide total global coverage. Even so, such satellite data merging is complicated by the fact that each individual satellite
observation represents a single 'snapshot' of the cloud patterns, each taken at slightly different times, whereas the underlying clouds themselves
are constantly moving and evolving.
In this depiction of global clouds, these satellite data are processed to discriminate clear (transparent) and cloudy areas. For cloudy areas, the
brightness is approximated based upon the cloud top temperature relative to the surface temperature, as a proxy for the height of each cloud pixel.
Due their location near the Earth's surface, low level clouds such as stratocumulus and stratus (fog) clouds may be poorly represented.
For more information, visit the Naval Research Laboratory (NRL) Marine Meteorology Division.
Conditions and Forecasts
Current Conditions - Current conditions on Google Earth are sourced from weather.com and are powered by HiRAD (High Resolution Aggregated Data), an
exclusive patented technology developed by The Weather Channel. HiRAD delivers a highly localized, extremely timely, and precise snapshot of current
weather conditions for any location within the contiguous United States. HiRAD analyzes and combines surface weather observations with other data
sources such as Doppler radar, weather satellites, a lightning detection network, weather prediction computer models, and climatology profiles to
provide unique up-to-date conditions for 1.9 million locations.
The HiRAD system literally fills in the gaps in the current reporting system, which relies on a sparse network of weather stations spread about the
country. With computer modeling that creates exclusive, high quality assessments of weather conditions less than one mile from any arbitrary location,
this technology enables users to monitor and track current conditions with details such as current precipitation (for example rain, snow, fog, and
thunderstorms), cloud cover (for example mostly sunny, cloudy), and visibility (an important detail when conditions are snowy or foggy), which are
typically not provided with other specialized weather networks.
---Taken from Google
On a side note. That is an awful lot of bragging about their best in the world system and it's methods, seeing as for the last three days it has been
on the fritz BIG TIME.
[edit on 6-10-2008 by turk182]