Environmental Engineering Reference
In-Depth Information
(NESDIS), supports weather forecasting, severe storm, tracking, and meteorology
research. Spacecraft and ground systemwork together to provide a continuous stream
of environmental data. The National Weather Service (NWS) uses the GOES system
for its United States operational weather forecasting and monitoring, and scientific
researchers use the data to better understand land, atmosphere, ocean, and climate.
The GOES system uses geosynchronous satellites which—since the launch in
1974—have been a basic element of US weather monitoring and forecasting.
Designed to operate in geostationary orbit, 35,790 km (22,240 statute miles)
above the Earth, thereby remaining stationary with respect to a point on the ground,
the advanced GOES I-M spacecraft continuously view the continental United
States, observing environments of the Pacific and Atlantic Oceans, Central, South
America, and southern Canada. The three-axis, body-stabilized spacecraft design
enables the sensors to “stare” at the Earth and thus more frequently image clouds,
monitor Earth's surface temperature and water vapor fields, and sound the atmo-
sphere for its vertical thermal and vapor structures. Before being launched, GOES
satellites are designated by letters (-A, -B, -C
). Once a GOES satellite is
launched successfully, it is redesignated with a number (-1, -2, -3
...
). So, GOES-
A to GOES-F became GOES-1 to GOES-6. Because GOES-G was a launch failure,
it never received a number. Since then, GOES-H to GOES-N became GOES-7 to
GOES-13.
In this chapter, we mainly focus our efforts to derive the LST products from the
imager of the GOES satellites currently available for operational use:
• GOES-12 is designated GOES-South, currently located at 75
W over the
Amazon River.
• GOES-13 is designated GOES-East, currently located at 105
W. It provides
most of the U.S. weather information.
• GOES 14 was placed in orbit on 7 July 2009, underwent Post-Launch Testing
until December 2009 and then was placed in on-orbit storage.
The GOES imager is a multichannel instrument designed to sense emitted and
reflected energy from sampled areas of the Earth. The multielement spectral
channels simultaneously sweep east-west and west-east along a north to south
path using a two-axis mirror scan system.
The GOES imager before GOES-12 had five channels centered at 0.67, 3.9, 6.7,
11, and 12
...
m channels are infrared
windows with little water vapor absorption, while the 6.7-
μ
m, respectively. The 3.9-, 11-, and 12-
μ
m band is a water
vapor band that can be used to detect atmospheric water vapor in the upper
troposphere. The 0.67
μ
μ
m is a visible band that can be used to detect clouds during
daytime.
The transmittance of the four thermal channels of GOES 8-11 vs. surface skin
temperature distribution is shown in Fig.
19.1a
. The transmittance at the 6.7-
m
water vapor band is almost zero for skin temperature above 240 K. The surface
radiation is almost totally absorbed by water vapor, so this band can be used to
detect atmospheric water vapor distribution, but not for retrieving surface skin
μ
Search WWH ::
Custom Search