Lecture No. : Satellite Meteorology
 
The color statements (not links) provide the answers to the questions 
in the Study Guide. Please click the word “Links” above for more
Information (in the Content Modules of the Course homepage).
 
 
1. Scanning Devices
 (1). Television camera (TV or visible photos).
  A. Regular TV camera or scanning radiometer.
  B. Reflected visible sun light.
  C. White (bright) and gray tones correspond to high and low
  clouds, respectively.
  D.  Land and water: light dark tone.
  E. Only taken during the day.
  F. Can sense moonlight or city light at night.
  G. Not good in detecting thin cirrus (small reflection).
  H. Sharp image edges (visually different from infrared 
  images). 
 (2). Infrared scanning radiometers (sensors) 
  A. Emitted radiation from objects (clouds, fog, water, and
 land).
  B. GOES Radiometer detects 10.5 to 12.5 microns infrared
  radiation from clouds, land, and water, etc.
  C. White: high clouds (low temperature).
  Gray: low clouds or fog (warmer temperature).
  Dark: land or water (warmest object).
  D. Can take nighttime photos.
  E. Good in detecting high clouds (cirrus).
  F. Poor in detecting low clouds (warm clouds, small
  contrast with it surrounding air).
  G. Summer night: coastline can not be detected because of
  almost same temperature.
 (3). Enhanced color photos
   A. Various temperature classes for different colors or 
  Different shades (white, gray, dark).
  B. Color enhanced imagery is a method meteorologists use to 
  aid them with satellite interpretation. The colors enable 
 a meteorologist to easily and quickly see features which 
 are of special interest to them. Usually they look for 
  high clouds or areas with a large amount of water vapor. 




 
 
 
  C. In an infrared (IR) image cold clouds are high clouds, so 
  the colors typically highlight the colder regions. 
  D. In a water vapor image, white areas indicate moisture and 
 dark areas indicate little or no moisture, so the colors 
 typically highlight areas with large amounts of moisture.  
2. Terminology
 (1). Principal point
  The point on the earth where the camera in satellite is
  focused.
 (2). Subpoint
  The point on the earth directly below the satellite at any
  given time during its orbit.
 (3). Nadir angle
  A. The angle between the principal point and subpoint.
  B. Most modern satellites are designed to have zero nadir
  angle (principal point and subpoint are the same).
 (4). WEFAX
  Weather facsimile data relayed via satellites.
 (6). Apogee
  The point in the orbit at which the satellite is farthest 
 From the center of the earth.
 (7). Perigee
  The point in the orbit at which the satellite is closest 
  to the center of the earth.
 (8). Ascending node
  The point at which the satellite in its orbital motion 
  Crosses the equator going from south (southern hemisphere) 
  to north(northern hemisphere).
 (9). Descending node
  A. The point at which the satellite crosses the equator 
 Going from north to south.
  B. Approximately but not exactly 180o longitude difference
  from ascending point because of the rotation of the 
  earth.
 (10). APT (Automatic Picture Transmission)
  A. The system aboard satellites that automatically transmit
   pictures (real time) without storing them.
  B. Sensors: TV camera and Scanning Radiometer (SR).  
3. Types of Orbits
 (1). Sun-synchronous orbit (Polar-Orbit Operational Environmental 
  Satellite or POES)
  A. The satellite always passes over the equator at the same
  sun times (local times) because the earth rotates.
  B. The satellite passes or nearly passes over both of the
  earth's poles.
  C. Low altitudes: 650-1500 km (400-900 miles).
  D. 12-14 orbits daily.
  E. Duration of each orbit: 90 to 110 minutes.
  F. TIROS, ESSA, ITOS, NOAA, NIMBUS, AND LANDSAT.
  G. Repetitively viewing large areas with high, medium, and 
  Low resolution sensors under similar solar illumination 
 and orbital operating conditions.
  H. Near-to global data recorded by tape recorder.
  I. TIROS N and NOAA 6:
  (A). In circular polar orbits every 102 minutes.
  (B). At about 850-km elevation.
  (C). Pictures in strips about 1800 km wide from pole to
  pole.
  (D). See a particular place twice a day (daylight and
  darkness).
  (E). The two satellites see a storm 4 times a day in
  total.
  J. NPOES 
  (A). The National Polar-orbiting Operational Environmental 
    Satellite System (NPOESS) will converge existing 
 polar-orbiting satellite systems under a single 
 national program. Polar-orbiting satellites observe 
 Earth from space. 
  (B). The polar orbiters are able to monitor the 
 entire planet and provide data for long-range weather 
 and climate forecasts. 
 (C). The program is managed by the tri-agency Integrated 
 Program Office (IPO) utilizing personnel from the 
 Department of Commerce, Department of Defense and NASA. 
  (D). The current NPOESS mandate extends to the year 2018. 
 (2). Earth-synchronous orbit (geostationary orbit)
  A. The satellite moves at the same speed and direction as 
  the rotation of the earth (11,000 km/hr or 5936 knots at 
 equator).
  B. The satellite moves eastward and makes one complete orbit
  approximately every 24 hours (23 hours 56 minutes).
  C. The satellite is always at the same location above a 
  given point of the earth.
  D. The orbit may be over any latitude circle.
  E. Absences of ascending and descending nodes.
  F. High altitude: 35,850 km (22,300 miles).
  G. Observe the same area or weather system continuously 
  with visible and infrared instrument. 
  H. ATS and SMS/GOES series.
4. History of Weather Satellites
 (1). The satellite program began in 1959: Vanguard and explorer.
 (2). TIROS 1 (Television and InfraRed Observation Satellite):
  A. April 1, 1960, the first weather satellite.
  B. TIROS series: 1 through 10, 1960 through 1965.
  C. Experimental vehicles to test various procedures for
  observing the atmosphere from space.
 (3). GOES (Geostationary Operational Environmental Satellites):
  A. Operational SMS: GOES-1 through GOES-7 (GOES-EAST or H).
  B.  GOES I-M series: The five new generation satellites.
  (A). GOES-EAST (GOES-8 or GOES-I, now GOES-12 or GOES-M): 
  a. At 75 oW.
  b. Overlooking North America, South America, and 
 the Atlantic ocean.
  c. GOES-8: Launched on April 13, 1994 and 
  de-orbited on May 5, 2004.
  d.  GOES-12: Launched on July 23, 2001. Operating 
   as GOES East since the spring of 2003.
  (B). GOES-WEST (GOES 9 or GOES J, Now at 200 oW as backup): 
  a. At 135 oW.
   b. Overlooking the North and South Americas,Hawaii, 
  and well out into the Pacific Ocean.  
  c.  GOES-9: Launched on May 23, 1995, stationed 
  over the Gulf of Mexico for testing(90 oW), 
  has become GOES-WEST (135 oW) since December, 
  1995. Providing support to the Japanese 
  Meteorological Agency (JMA). 
  d. GOES-10: Launched on April 25, 1997 and was 
  placed in orbit at 105 oW. Was shutdown in 
  1998 and designated as ”on-orbit spare”. Has 
  Become GOES-WEST after GOES-9 began 
  experiencing problems with its momentum 
  wheels.
  e. GOES-11 (GOES-West or L, 135 oW): 
  Launched and placed in storage mode in 2000.
  Now becomes primary.
  

Satellite	GOES-8	GOES-9	GOES-10	GOES-11	GOES-12
Location*	195° W	200° W	135° W	135° W	75° W
Status	Deactivated 5/5/2004	Backup	Standby Drifting	West Primary	East Primary

GOES satellites operate at an altitude of 35,800 km

*Geostationary operational orbits are defined by their location over the equator.

   C. GOES-N, O, P: Improved GOES I-M series. GOES-NEXT 
 (GOES-N)to be launched in 2006.
  D. GOES-R: Planned to launch in 2012. Currently in the 
  formulation phase. The first of a new 3rd generation 
 of three-axis stabilized satellites with an entirely 
  new sensor complement. The definition phase of this 
  program started in 2000.  
  E. Weather forecasts on American television: film loops
  showing weather in motion. 
  F. Resolution
  (A). visible spectrum: 1/2 to 2 miles.
  (B). infrared spectrum: 4 miles.
  white: the coldest surface (cloud).
  black: the warmest surface.
  various shades: various temperatures.
5. Wallops Island, Virginia
 Receives original satellite signals. After certain electronic
 manipulations, the signal is sent to Suitland, Maryland and to the
 headquarter of the National Environmental Satellite Data and
 Information Service (NESDIS) and from there it can be transmitted 
 To various users throughout the country equipped with receivers to
 produce satellite photographs. 
6. Cloud Patterns
 (1). Open cellular clouds (Ring clouds)
  A. Composed of cloudless, or less cloudy, centers 
 Surrounded by cloud walls with a predominant ring or 
 u-shape.
  B. Location
 The rear of a cold polar front with a cyclonic flow.
  C. Cold air advection over warm water to the rear of a 
 cold polar front (unstable air, heating from below).
  D. Cause: large air-sea temperature difference: 3 oC 
 or more .
  E. As, Ac or Cu
 (2). Closed cellular clouds (Bean clouds)
  A. Bean-shaped or lump-shaped clouds.
  B. Location
 South of open cellular clouds in the rear part of a 
 cold front.
 South of a polar high with an anticyclonic flow. 
  C. Cold air advection over warm water (heating from below).
  D. Smaller air-sea temperature difference: less than 3 oC.
  E. Sc.
 (3). PVA (positive vorticity advection) area:
  A. Area of enhanced convective (cyclonic) activity: strong
 vertical motion.
  B. Comma cloud.
  C. Cumulus congestus or Cb.
  D. A clear slot ahead of the positive vorticity advection
 area.
 (4). Sun glint
  A. Reflection of sun light from the calm (smooth) ocean
 surface.
  B. High pressure center: calm wind.
  C. Appears as stratus or fog.
 (5). Fog 
  A. Looks like stratus (gray tone).
  B. Extent of Fog follows topographical contours.
 (6). Fronts
  A. Bright elongated bands of clouds, oriented in 
 north-south direction.
  B. Low center: Often cloudless with spiraling clouds
 extending outward.
  C.  Ci, Cb, St. Cu , Ns (all types of clouds).
 (7). Jet stream
  A. Long meandering cloud bands.
  B. North of Cirrus shield.
  C. High clouds.
 

GOES (NOAA and NASA) websites (optional)

http://www.nesdis.noaa.gov/satellites.html

http://www.ipo.noaa.gov/ (NPOES)

http://www.goes.noaa.gov/enhanced.html (enhanced color)

http://www.osd.noaa.gov/GOES/goes-11.asp

http://goes.gsfc.nasa.gov/ (GOES 12)

https://osd.goes.noaa.gov// (GOES R)

http://goespoes.gsfc.nasa.gov/goes/index.html (GOES project)

http://goespoes.gsfc.nasa.gov/poes/index.html (POES)

http://www.oso.noaa.gov/goes/index.htm

http://www.oso.noaa.gov/poes/index.htm

http://goes.gsfc.nasa.gov/text/summary.html

http://goes.gsfc.nasa.gov/text/goesimbroch.html (GOES N)

http://images.eoportal.org/

http://www.osd.noaa.gov/GOES/goes_n.htm (GOES NOP)

http://www.boeing.com/news/releases/2005/q2/nr_050407n.html (GOES R)

http://www.geoplace.com/pressrelease/detail.asp?id=9591 (GOES R)

http://goespoes.gsfc.nasa.gov/goes/spacecraft/r_spacecraft.html (GOES R)

http://science.hq.nasa.gov/missions/satellite_67.htm (GOES R)

http://goes.gsfc.nasa.gov/text/goesnext.html (GOES Next)

http://goes.gsfc.nasa.gov/text/goes.lessons.html

http://www.ssd.noaa.gov/
http://www.ncdc.noaa.gov/oa/satellite/satelliteresourcesabout.html