GEO-NEWS AROUND THE WORLD
last updated 11 May 2011

• GOES Satellites
• Non-GOES Geosynchronous Weather Satellites
• CGMS, Coordination Group for Meteorological Satellites
• Jordan's list of WeatherSat Sites
• Basic facts about the OKEAN/SICH polar satellites
• Spectral response curves for the weather satellite imagers, listed at NASA-GISS
• Archive of 3-hourly composites of geosynchronous satellite images
• ZombieSats and Orbital Debris in GEO (2010)

Personal, brief summaries for the non-GOES geosynchronous weather satellites, gleaned from semi-reliable sources:

• Europe: METEOSAT
  • Europe: MSG
  • Europe: MTG
• Japan: GMS
  • Japan: MTSAT
  • Japan: HIMAWARI
• China: FENG-YUN-2
  • China: FENG-YUN-4
• Russia: GOMS
  • Russia: ELECTRO-L
• India: INSAT
• Korea: COMS
• Canada: PCW

Current Earthview from any satellite

METEOSAT

• As of November 2003, EUMETSAT operates METEOSAT-7 at 0 E longitude, and distributes its products. The standard mode of operation is full-disk imagery in 3 channels every half-hour.
  As of April 2006, METEOSAT-7 is out of inclination-keeping fuel, and operations will be switched to MSG/METEOSAT-8 in May 2006. EUMETSAT plans to terminate METEOSAT-7 operations on 14 June 2006.
  METEOSAT CHANNEL CHARACTERISTICS

  Image Band	VIS	WV	IR
  spectral range	0.45-1.0 um	5.7-7.1 um	10.5-12.5 um
  resolution at nadir	2.5 km	5.0 km	5.0 km

  In 1995, EUMETSAT began encrypting digital images and selling commercial licenses to receive METEOSAT real time broadcasts. EUMETSAT has made an international arrangement for METEOSAT encrypted data distribution via NOAA. Non-commercial users can arrange to get it from NOAA - contact John Pacquette at NESDIS. Fortunately, the METEOSAT-7 WEFAX images are still available in real time from EUMETSAT and from other sites in Europe, such as Nottingham, England. EUMETSAT posts a dissemination schedule. Radiometric calibration of the first-generation METEOSATs is indirect, through calculations and secondary earth-targets. METEOSAT navigation can be estimated using geometry and FORTRAN code.

  • METEOSAT-7 was launched on 3 September 1997. It is the last of this series. It is the prime operational satellite, located at 0 longitude. It is planned to continue operations until the end of 2005, operating in parallel with the new MSG-1 during its commissioning in 2003.
  • METEOSAT-6 was launched in 1993. METEOSAT-6's performance is errratic, and so it is kept as an emergency spare positioned at 10 E. In September-November 1999, METEOSAT-6 was used in a rapid-scan imaging experiment to study weather in the Mesoscale Alpine Program. Some of the routine half-hourly full-disk images were replaced by six 5-minute scans of Europe. In September 2001, METEOSAT-6 was dedicated to continuous rapid scans of 15-65 North latitude every 10 minutes.
  • METEOSAT-5 was launched in 1991. It was being kept as an on-orbit spare at 10W until the INDOEX experiment of 1998-1999 (see below). After IDOEX, it remains at 63 E and generates hourly full-disk images of the Indian Ocean, where expected to operate until at least the end of 2001.
  • METEOSAT-4 was launched in June 1989. METEOSAT-4 was taken out of service on 9 November 1995, and moved to a graveyard orbit, 200 to 300 kilometers above geostationary altitude.
  • METEOSAT-3 was launched in June 1988. In the early 1990's, METEOSAT-3 was stationed at 70W, where was an emergency backup for a few years to fill the GOES-EAST slot at 75W. The METEOSAT-3 lease with NOAA ran out in November 1995, and METEOSAT-3 was to be moved to a graveyard orbit, 200 to 300 kilometers above geostationary altitude.
• The orbital status of the GOES and METEOSATs are updated occasionally at NOAA.

METEOSAT-INDOEX

An American site at UCSD describes the INDOEX science.

METEOSAT-5 has been re-located to a position around 63E. The re-location lasted from 14 January until 18 May 1998. The routine INDOEX mission started in July 1998.

Only high resolution image formats will be disseminated on channel A2. There are AIVH and AW formats during daylight and AIW during night. PDUS reception coverage is possible from about 135E to 4W. A subset of the images taken by Meteosat-5 will be disseminated as hourly X-formats (XI, XVH) via the prime mission satellite at 0E. Additionally some reduced image formats are made available via the Internet at 3-hourly intervals.

Due to the high orbit inclination of METEOSAT-5, users may require a special PDUS set-up:
Use of a smaller diameter antenna or
Defocusing of the antenna feed.

PDUS users will require two separate reception systems for direct reception of image data from 0E and 63E simultaneously. MKU's are required for other than 6-hourly image intervals.

Users who receive the HRI images from Meteosat-5 either directly or via the prime mission spacecraft, should note that these images can be easily distinguished from the other Meteosat images by checking the parameters in the identification field of the dissemination formats, i.e. the satellite identifier (bytes 1 and 2) and the longitude of the sub-satellite point (bytes 25 and 26).

INDOEX satellite images are on-line at EUMETSAT.

Data Policy for INDOEX

Below is a brief description of EUMETSAT's Data Policy for INDOEX. In view of the short term experimental nature of this activity, this deviates from EUMETSAT's standard Data Policy.

INDOEX real time data are available free of charge to all users for any type of use. Access to encrypted real time data will be subject to a license agreement, in order to ensure the protection of EUMETSAT's Intellectual Property Rights. The necessary decryption key unit (MKU) will be provided to users at the currently applicable cost (700 ECU).

Access to INDOEX data archived in the MARF is also free of charge except for the payment of marginal costs of delivery as currently applicable. Again, access to MARF data will be subject to a simplified license agreement, in order to ensure the protection of EUMETSAT's Intellectual Property Rights. The Data Policy for INDOEX will apply only for the duration of the INDOEX activity, as agreed at the 34th EUMETSAT Council, i.e. until the end of 1999.

MSG, aka METEOSAT II

EUMETSAT's MSG satellite carries a 12-channel spinning Imager called SEVIRI, with a 1 km resolution visible band and 3 km resolution infrared bands, 8 of which are in the thermal infared.

There is a MSG glossy brochure (2.5 MB PDF).

MSG is capable of full-disk images every 15 minutes. With a 60-cm aperture and a ton of spin-stabilized mass, imagery is sharp and stable.

Bandwidth limitations allow it to only downlink half of the 1 km resolution visible data (the left, middle, or right portion of the full-width scan). Their notion of data compression is to throw away half the image.

MSG-1 was originally scheduled to launch in October 2000, but was delayed until July 2001 to deal with issues with the launch (moving from a dedicated launch on Ariane-4 to a rougher, shared launch on Ariane-5) and the ground segment. Further concerns about the ground system readiness delayed the launch schedule to August 2002. The MSG-1 satellite was successfully launched on 28 August 2002, and turned over to EUMETSAT on 25 September. First public imagery was due in late October 2002.

However, on 17 October 2002, a power supply switched off unexpectedly. Since then, the three remaining power supplies are being babied, preventing the global rebroadcast of the full resolution imagery, which will have to be routed through commercial communications satellites. As of November 2003, SEVERI HRIT and LRIT data is transmitted via EUMETCast, a satellite DVB broadcast system that provides coverage over Europe, Africa, the Middle East and parts of eastern North and South America.

The first official full-disk images were taken by MSG-1 on 28 November 2002.

After launch, there was one year of commissioning the ground system and validating calibrated imagery from MSG-1.

When MSG-1 became operational in 2004, it was renamed METEOSAT-8.

MSG-2 was originally scheduled for launch in 2002; it was eventually launched in 21 December 2005 on an Ariane-5 rocket. The first image was taken 24 January 2006.

MSG-3 was originally scheduled for launch in 2006; as of May 2003, it is scheduled for 7 years after the launch of MSG-1 (in 2009).

In spring 2003, EUMETSAT contracted for MSG-4 at a cost of 391 euros.

The total cost of MSG to EUMETSAT through 2015 will be 1,637 billion euros.

ESA has posted a Research Announcement of Opportunity (RAO) that solicits proposals to develop new and better satellite data products from MSG.

MTG, aka METEOSAT III

EUMETSAT's MTG mission will consist of satellite pairs, one carrying a multispectral imager (MTG-I), the other a hyperspectral sounder (MTG-S). For the first time in the METEOSAT series, the satellites will be 3-axis stabilized, with constantly earth-pointing instruments.

The imaging satellite will carry a 16 channel scanning imager, and a high-resolution 4 channel mesoscale imager. The sounding satellite will carry an infrared instrument for temperature-moisture profiling, a lightning mapper, and a reflected sunlight instrument for pollution tracking over Europe.

The scanning imager (FCI) will have 8 channels using reflected sunlight at 0.4, 0.5, 0.6, 0.8, 0.9, 1.3, 1.6, and 2.2 microns. The scanning imager will also have 8 channels using thermal emission at 3.8, 6.2, 7.3, 8.7, 9.7, 10.5, 12.3, and 13.3 microns.

The pollution tracking instrument (UVN) will have channels in the ultraviolet, visible, and near infrared bands to track trace gases and aerosols.

As of 2009, the launch schedule for the imaging satellites is for MTG-I-1 in 2015, MTG-I-2 in 2020, MTG-I-3 in 2024, and MTG-I-4 in 2028. The launch schedule for the sounding satellites is for MTG-S-1 in 2018, and MTG-S-2 in 2026.

By the mid-2030's, METEOSAT Fourth Generation (MFG) will be needed.

Additional information about European satellites

• URLs
  • http://www.eumetsat.int/ [EUMETSAT]
  • http://www.esrin.esa.it/ [ESA ESRIN]
  • http://earth.esa.int [ESA ESRIN Earthnet Online - Earth Remote Sensing]
  • http://www.ssc.se/ [SSC]
  • http://www.cnes.fr/ [CNES]
  • http://www.dfd.dlr.de/ [DLR]
  • http://www.knmi.nl/home/Home.html [KNMI]
  • http://www.wmo.ch/ [UN WMO]

GMS

• GMS-5 was launched in the spring of 1995. GMS-5 became the operational Japanese geosynchronous weather satellite in June 1995. GMS-5 reached its 5-year design life in the spring of 2000.
  GMS-5 is operated by The Meteorological Satellite Center (MSC) of the Japan Meteorologcial Agency.
  GMS-5 broadcasts on a roughly hourly schedule, stationed at 140E longitude.
  In June 2001, GMS-5 reduced its southernmost coverage to deal with increased torque in the scan mirror motor at the end of the rotation (probably due to lubricant buildup).
  In the spring of 2003, GMS-5 was replaced by GOES-9.
  The spin-scan imager on GMS-5 carries four channels:
  • a visible channel at 1.25 km spatial resolution
  • a thermal infrared (11 micron) channel with 5 km resolution
  • a thermal infrared (12 micron) "split window" channel with 5 km resolution
  • a thermal infrared (6.5 micron) water vapor channel with 5 km resolution
  The GMS-5 high-resolution image format is the same as the old GOES-7 VISSR broadcast in the S-band, similar to the format used by GOES-7, since it is a copy of that satellite. GMS-5 receivers of the raw digital data can use a table-lookup to convert counts to albedo and brightness temperature.
• GMS-5 operational images are served in realtime from NASA-GSFC. These are received at the University of Hawaii and pumped to NASA over the internet.
• 1997 was an ENSO year, with the Asian monsoon shifted far north east into the East China Sea (10 MB QT movie), and sporting a number of super-typhoons south of Japan, such as Typhoon Winnie (5 MB QT movie), which struck China a direct blow.
• GMS-5 also saw the ordinary-looking storm that injured over 100 people and killed 1 by in-flight turbulence in the middle of the night on 28 December 1997.
• GMS-5 images are now also served on-line in Japan, they can ordered as a video loop from the Japanese Weather Association (JWA):

       Date: Mon, 11 Nov 1996
       Subject: GMS-5 data archive
  
       Dear Sir,
   
       With reference to your mail dated 5 November 1996 concerning GMS image, our
       office, Japan Weather Association (JWA) can provide you an analog VHS video
       tape of image titled "Time Lapse Cloud Movie" or a photographic print. Any
       other media including digital form for images is not available.
   
       Our e-mail address is kokusai@jwa.go.jp.
     

• GMS-5 made its final S-VISSR observation on May 22 @ 00Z and has been replaced by GOES-9.
• GMS-4 was launched in September 1989. GMS-4 WEFAX images were widely used around the Pacific rim. GMS-4 was finally moved to a graveyard orbit, 600 km above geosynchronous altitude, on 24 February 2000.

MTSAT

MTSAT is a Japanese weather satellite for geosynchronous orbit. MTSAT is a three-axis stabilized spacecraft and carries both a meteorological mission and an aeronautical communications mission. The Japan Meteorological Agency (JMA). contracted for MTSAT as a successor to GMS-5, in cooperation with the Civil Aviation Bureau (CAB), of the Ministry of Transport of Japan. The Japanese weather satellites are operated by JMA's Meteorological Satellite Center.

MTSAT SPECIFICATIONS
Design Life	more than 5 years for the meteorological mission, more than 10 years for the air traffic control mission
Survival Probability (Estimated)	0.89 or greater for 5 years for the meteorological mission 0.81 or greater for 10 years for the air-traffic control mission
Orbital Position	+/- 0.1 degrees north-south and east-west, from its nominal position of 140E longitude
Imaging period	Full earth disc within 27.5 minutes
Imager characteristics	Visible 0.55 - 0.80 micron IR1 10.3 - 11.3 micron IR2 11.5 - 12.5 micron IR3 6.5 - 7.0 micron IR4 3.5 - 4.0 micron
Signal quantisation	10 bits for both Visible and IR
Resolution (at the sub-satellite point)	1 km for Visible, 4 km for IR
Imager Data Transmission Rate	2.62 Mbps
Telecommunications	Transmission of raw image data
Functions	Relay of High REsolution imager data (HiRED) Relay of WEFAX and LRIT signals Relay of DCP reports Relay of DCP interrogation messages

In the late 1990's, MTSAT-1 was constructed by Space Systems/Loral, and integrated with an Imager by ITT/Fort Wayne, and shipped to Japan in March 1999. Unfortunately, the Japanese H-2 rocket launch failed in mid-November 1999.

The MTSAT-1 replacement is called MTSAT-1R. In March 2000, the contract for MTSAT-1R was awarded to SS/Loral. Launch was originally scheduled for March 2003. In November 2001, the MTSAT-1R launch was rescheduled to mid-summer 2003, due to delays created by US technology transfer restrictions. In the spring of 2003, launch was rescheduled to early 2004, due to problems during thermal-vacuum testing of the MTSAT Imager. In the fall of 2003, SS/Loral went bankrupt, temporarily delaying the shipment of MTSAT-1R. MTSAT-1R was successfully launched on 26 February 2005. MTSAT-1R became operational in mid-2005 at 140E longitude.

On MTSAT-1R, a Japanese Advanced Meteorological Imager (JAMI) was supplied by Raytheon/Santa Barbara Research Systems (SBRS), not by ITT/Fort Wayne. The imaging schedule calls for one full-disk and one northern hemisphere scan per hour for cloud-tracked wind estimation.

MTSAT-1R's first published full-disk images were taken at midday on 23 March 2005. After becoming operational in mid-2005, the MTSAT-1R images are being published on the web.

MTSAT-1 is similar to the GOES-I/M Satellites, but carrying more communications gear and no Sounder. The MTSAT-1 5-band Imager by ITT had performance improvements over the GOES-I/M Imagers by ITT:

• half the noise in the visible
• a calibration procedure for the visible channel
• twice the spatial resolution in the 6.7 micron water vapor channel
• a baffle to stop stray light near midnight

MTSAT-2 was launched on 24 February 2006. MTSAT-2 will be left in cold storage on-orbit at 145E longitude until it is needed to replace MTSAT-1R, circa 2010. The MTSAT-2 spacecraft contract was awarded late in 2000 to MELCO, also known as Mitsubishi Electric Space Systems, with MTSAT-2's Imager to be supplied again by ITT/Fort Wayne. The major improvement in the ITT Imager is the noise performance of the infrared channels. MTSAT-2 will be the first to employ Mitsubishi's new communciations bus.

In May 2010, JMA began preparations to switch from MTSAT-1R to MTSAT-2 on 1 July 2010.

In Japan, JMA refers to MTSAT-1R as HIMAWARI-6 and MTSAT-2 as HIMAWARI-7, while the MTSAT names are used in the western press.

HIMAWARI

• In 2009, JMA selected Mitsubishi Electric to build the next two geosynchronous meteorological satellites, HIMAWARI-8/9 for 40 Billion Yen (US$420 Million), excluding launch costs on an H-IIA rocket.
• Launch of HIMAWARI-8/9 are scheduled for 2014/16, the first a year before the expected end-of-life for MTSAT-2.
• The budget for HIMAWARI-8/9 was too small to include the development of a custom imager, so they contracted with ITT/Fort Wayne to buy copies of the ABI instrument being developed for GOES-R.

FENG-YUN-2

• Feng-Yun-2 are China's first series of geostationary meteorological satellites, built by the Shanghai Institute of Satellite Engineering. They are very similar to the Japanese GMS and the USA's GOES-3/7 spin-stabilized satellites originally built by the Hughes Corp. in the USA.
• The cylindrical satellite measures 2.1 m by 1.6 m, and is dual spin-stabilized at a rate of 100 rpm.
• The main payload of FY-2 is a Visible and Infrared Spin Scan Radiometer (VISSR) which obtains hourly full-disk images of the Earth, through step action of the scan mirror, in three channels: visible (0.55-1.05 micrometer), infrared (10.5-12.5 micrometer) and water vapour (6.2-7.6 micrometer).
• The visible channel makes observations and derives reflectance of clouds and the Earth surface during daylight hours while the infrared channel senses heat radiation at all times. The water vapour channel measures the amount of water vapour in the middle and upper atmosphere.
• The subsatellite resolution is 1.25 km for the visible channel and about 5 km for the infrared and water vapour channels.
• Other functions of FY-2B include monitoring solar activities such as emission of x-ray and particle radiation; collecting and transmitting meteorological, oceanographic and hydrologic data; and broadcasting stretched digital images, low resolution cloud and WEFAX images, synoptic maps and processed products.
• The FY-2 satellites are operated by the China Meteorological Administration (CMA), National Meteorological Satellite Center (NMSC).
• The first FY-2 satellite to be built was destroyed on the ground when the rocket blew up during a fueling accident on 2 April 1994, killing 1 person and injuring at least 20.
• The second FY-2 satellite to be built was successfully launched to 105 degrees East longitude on 10 June 1997, and began regular service late in 1997. It is called FY-2A. However, due to a problem with the S-band antenna on the spacecraft on 8 April 1998, FY-2A ceased transmission of VISSR images, to resume for a few hours on 10 April. CMA managed to regain earth lock and ranging with the S-band antenna for 12 hours on 14 April 1998, but there were no regular S-VISSR re-transmissions during the summer of 1998. Sarting late in 1998, CMA was able to get raw image downlinks a few times per day, and to make one full-disk picture each day. In March 1999, FY-2A ceased transmitting images and moved to 86 E.
• FY-2B was launched on 25 June 2000. The meteorological satellite reached its orbital slot at 105 E longitude over the equator in July. There was to be a six-month on-orbit checkout of the satellite before it went into full operation. The design life of FY-2B is three years. As of November 2003, FY-2B was apparently suffering spin-stabilization problems similar to FY-2A. In August 2004, it was moved to storage at 123.5 E.
• FY-2B captured images of Typhoon Xangsane in late October 2000, which was raging during a Singapore Airlines crash during a takeoff in Taiwan
• FY-2C was launched on 19 October 2004. It's first visible image was taken on 29 October 2004. It was put into operations in July 2005 at 105 E. FY-2C will be moved to storage late in 2009.
• FY-2D was launched on 8 December 2006, and became operational in June 2007 at 86.5 E. It will form a "twin-star" observation system with FY-2C. The two satellites have their own observation tasks, but they can also replace each other if one of them malfunctions. Each satellite scans the Earth in 30 minutes. They start scanning 15 minutes apart to provide 4 full-earth scans per hour, to support weather forecasting during the 2008 Olympics in Beijing.
• FY-2E was launched on 23 December 2008, and kept in on-orbit storage until it replaces FY-2C late in 2009.
• FY-2F, FY-2G and FY-2H are scheduled to be launched in 2010, 2012 and 2014 respectively, and each put into operations in the following year, with 4 year working lifetimes planned.
• Processed and animated images of China from FY-2 are posted on the internet by the Hong Kong Observatory.
• FY-2 broadcasts the image data in S-VISSR format, used by the old GOES and GMS satellites, described by China at http://nsmc.cma.gov.cn/fy2e.html .
• In 2004, China agreed to put its processed image data on a server in MCIDAS format for users to access. They have just begun to do this for their current geostationary satellite. Thus, all major operational satellite operators within CGMS will have their data available in a common format.
• The basic imaging properties of FY-2 are:

  FY-2 Spacecraft
  Attitude Stability		Spin stabilized (100 rotation/min)
  Orbital Altitude		35800km
  Services		S-VISSR, L-Fax, etc.
  Scan Radiometer
  Channel	Waveband	Nadir Resolution	Temporal Resolution
  Visible	0.55-1.05 micron	1.25 x 1.25 (km x km)	1 hour
  Water Vapour	6.2 - 7.6 micron	5 x 5 (km x km)	1 hour
  IR	10.5-12.5 micron	5 x 5 (km x km)	1 hour

• The first visible image by FY-2A was taken on 21 June 1997, and a thumbnail version of it is posted on the web. You can get a large (3k x 3k) version by clicking on that thumbnail image on that page, or you can get the large image from us by clicking here.
• The first infrared images by FY-2A were taken on 13 July 1997. Thumbnail versions of all three "first" images are posted here:
  • First FY-2 VIS, thumbnail image
  • First FY-2 IR, thumbnail image
  • First FY-2 WV, thumbnail image
• Click here for an IR-resolution full disk image from FY-2 on 23 December 1997, colorized to look natural (1.3 MByte download).
• FY-2 internet data service (when it was working, December 1997 to April 1998):

  NASA requested and obtained permission to receive and share FY-2 data. This satellite will provide much needed coverage of the central Asian Hemisphere on an hourly basis. NASA has arranged to receive the data in Adelaide, Australia at the University of Southern Australia, and to transmit some full-resolution data, as well as calculated real-time products and localized sectors, over the Internet through Hawaii to NASA's Ames Research Center and Goddard Space Flight Center. There, the data will join similar data already being provided for GOES-8/9 and GMS-5. The data will be a short-term archive of infrared-resolution images, on-line for perhaps a week. Long-term archiving of the data will be performed by anyone willing to download the images using anonymous FTP from the NASA sites.

  X-Sender: jdodge@mail.hq.nasa.gov
  Date: Mon, 11 Aug 1997 17:21:34 -0400
  Subject: Real-Time FY-2 Data
  
  Dear Colleagues:
  
  Many of you have expressed an interest in receiving geostationary 
  meteorological satellite data over the Asian Hemisphere.  As you know the
  Chinese have recently launched a successful geostationary satellite and
  placed it at 105 deg E. Highly-compressed samples of their three channels
  (VIS, IR, and WV) are provided as attachments to this e-mail.  Direct 
  broadcast of the FY-2 data will begin in Oct., 1997.  NASA has located a 
  ground station for direct reception of the data at the Univ. of Southern 
  Australia in Adelaide. The antenna has been erected, and the receiver, 
  built in Hawaii and tested on GMS, will be installed before reception begins.
  
  Since any geostationary satellite produces large volumes of data, and
  FY-2, with its three bands, and hourly observations is no exception, we plan
  to place a computer at the reception site to generate segmented or
  subsampled files for reduced-volume transmission of the key data sets
  for real-time projects.  We ask that you consider your real-time data 
  requests carefully and plan a regular downloading of the requested products
  before their residence on the temporary storage site expires.  Currently,
  we are planning a two-week residence time for the data.  The data will be
  mirrored through Ames Research Center, and the Goddard Space Flight
  Center.
  
  We ask that you submit your requests for various areas and/or
  formats of real-time data so that we may attempt to consolidate the 
  requests into reasonable sets of data that may satisfy the needs of 
  several users and thereby save storage space and processing time.
  
  Please send your requests for real-time data processing to Pat
  Coronado at the Goddard Space Flight Center (Tel.(301)286-9323) or
  e-mail him at:
  
     cwifs@suzieq.gsfc.nasa.gov
  
  and please copy me at
  
     jdodge@hq.nasa.gov
  
  Those persons responding with descriptions of their real-time
  data requirements will be sent instructions concerning the procedure
  and scheduling of data access.
  
  Also don't forget to check out the Chinese Web site for higher
  resolution versions of their first images:
  
  http://www.cma.go.cn/fy2/fy2.htm
  
  It would also help if you would give me a brief description of the
  research that your are planning to do with the data.  While we have heard
  of the desires to study the diurnal variabilities of various cloud regimes,
  and the interactions among atmospheric layers, as well as the evolution
  of large-scale storm systems, we are also interested to learn of the many
  possible atmospheric radiation interpretations, boundary layer-ocean
  interactions, multiple satellite analyses, latent heat exchange estimations,
  wind-wave relationships, rainfall estimation, and possible bioproductivity
  implications.
  
  Thanks for helping us to provide an efficient data access and 
  delivery system for what promises to be a great new source of 
  environmental satellite data.
  
  Jim Dodge
  
  
  ***************************************************************
  Dr. James C. Dodge
  Global Data Integration and Validation Program
  Science Division - Code YS
  Office of Mission to Planet Earth
  NASA Headquarters
  Washington, DC 20546
  Tel. (202)358-0763
  Fax (202)358-2770
  Email: James.Dodge@hq.nasa.gov
  ***************************************************************
  

  The spectral channels of VISSR on FY-2

  Channel	Wavelength (μm)
  	FY-2 A,B	FY-2 C,D,E
  VIS	0.50-1.05		0.50-0.75
  IR1	10.5-12.5		10.3-11.3
  IR2			11.5-12.5
  IR3			3.5-4.0
  WV	6.3-7.6		6.3-7.6

  The characteristics of VIS channels of VISSR

  Item	Characteristics
  	FY-2 A,B	FY-2 C,D,E
  Wavelength (μm)	0.50-1.05	0.50-0.75
  FOV(μr)	40	35
  Space resolution (km)	1.44	1.25
  Dynamic range	0-95%	0-98%
  S/N	6.5 (2.5%)	1.5 (0.5%)
  	43 (95%)	50 (95%)
  Number of detectors	4 (main) + 4 (alternate)	4 (main) + 4 (alternate)
  Quantization level	64	64
  Calibration	Cool-space images and solar image to realize in-orbit calibration	Same as FY-2 A,B

  The characteristics of IR, WV channels of VISSR

  	FY-2 A,B		FY-2 C,D,E
  	IR	WV	IR1		IR2	IR3	WV
  Wavelength (μm)	10.5-12.5	6.3-7.6	10.3-11.3		11.5-12.5	3.5-4.0	6.3-7.6
  FOV (μr)	160	160	140		140	140	140
  Space resolution (km)	5.76	5.76	5		5	5	5
  Dynamic range	180-330K	190-290K	180-330K				180-280K
  Temperature resolution	0.6K	1.0K	0.4-0.2K	0.4-0.2K		0.5-0.3K	0.6-0.5K
  Number of detectors	1(main)+1 (alternate)	1(main)+1 (alternate)	1(main)+1 (alternate)	1(main)+1 (alternate)		1(main)+1 (alternate)	1(main)+1 (alternate)
  Quantization level	256	256	1024	1024		1024	1024
  Calibration	On board blackbody calibration, once every 3 disks		The ground calibration accuracy is 1K. Cool space and planet calibration is used for on-board calibration, once every 2 disks.

• In the fall of 2004, the China Meteorologic Administration (CMA), sponsored by the Commission of Science and Technology Industry for National Defence, signed a contract for the research, manufacturing, launch and monitoring of the second generation of geosynchronous satellites, Fengyun-2 batch two (FY-2 02), which would be launched atop Long March 3A rockets. "China badly needs a stationary satellite like the FY-2 02 with its function of detecting sandstorms, forest and prairie fires," it quoted Qin Dahe, the top official at the China Meteorologic Administration (CMA), as saying.

• Downlinks
  The S-VISSR broadcast format is described at http://nsmc.cma.gov.cn/fy2e.html, and there is a local copy here.

  Subject: Re:  Fengyun-2 downlink freq
  From: mdk@bom.gov.au (Mike Kenny)
  Date: Wed, 5 Feb 97 10:29:04 EST
  
  The GMS SV downlink frequency is 1687.1 MHz
  
  The Feng Yun 2B (FY-2B) meteorological satellite is offically due for 
  launch sometime in 1997 and will be located at 105 degrees East.
  
  The FY-2B satellite will be operationally similar to GMS with
  high resolution stretched VISSR data (5km IR, 5km WV, 1.25km VIS),
  low resolution Wefax (analog), DCP capability and a new digital S-band
  fax service (CCITT G3) for domestic distribution of charts and imagery.
  
  FY-2B downlink characteristics
  
  Channel     Freq        Mod         Power       BW
  S.VISSR     1687.5 MHz  BPSK NRZ-M  +57 dBm     2 MHz
  LR-FAX      1691.0 MHz  AM/FM       +57 dBm     260 KHz
  S-FAX       1699.5 MHz  AM/FM       +46 dBm     26 KHz
  
  The Australian Bureau of Meteorology (BOM) is working with the China
  Meteorological Administration (CMA) on the Feng Yun 2B satellite and
  is providing a Turn Around Ranging Station (TARS) to support FY2AB
  operations as it does for the Japanese GMS satellite.
  
  ---
  Mike Kenny
  Satellite Engineering, Bureau of Meteorology, Melbourne, Australia.
  

• Calibration and Navigation
  For 1997, the orbital/navigation/calibration informormation included in the DOC sector of the S-VISSR downlink was mostly useless, and contained lots of checksum errors. Starting with FY-2C, the S-VISSR format was revised to version 2 and its usability was verified.

  Image Navigation for the FY2 Geosynchronous Meteorological Satellite, Lu, Feng, Xiaohu Zhang, Jianmin Xu, 2008: J. Atmos. Oceanic Technol., *25*, 1149-1165.
  

• Linguistics
  
  "Feng-Yun" means "Wind-Cloud", and I am told that it is pronounced "Phone-Wheeen?" ("?" indicates rising pitch, like an English question, OK?).

  By the way, the Chinese name all their weather satellites "Feng-Yun", often spelled "Fengyun" in the western press. They originally planned to use odd numbers for the low-earth orbiting birds (FY-1, FY-3, etc.), and even numbers for the geosynchronous birds (FY-2, FY-4, etc.). But then, naming conventions changed in the late 1990's, so that now the first-generation geosynchronous series are all called FY-2. For some years, their first geosynchronous satellite to be constructed (and destroyed in a fueling accident) was called "FY-2A", and the first satellite to be launched successfully was called "FY-2B". By the year 2000, the unsuccessful satellite was no longer given any alphabetical designation, and the first geo-satellite in space was being called "FY-2A". By the year 2006, the decommissioned FY-2A and -2B satellites were declared "experimental", and FY-2C was declared "operational" at 105E.

• Future Plans
  The FY-2E/F/G/H satellites follow on at two year intervals in the 2000-2010 decade and carry a 5-channel VISSR with enhanced signal/noise. The analog S-band WEFAX was to be stopped, and replaced by digital LRIT format. When there are enough functioning FY-2 satellites on orbit, China plans to go from a one satellite operation at 105E to a two satellite operation at 86.5E and 123.5E.

  In the mid-2000's, the FY naming convention changed again, with alphabetical designations for the pre-launch spacecraft, changed to numerical designations on orbit. FY2-D was launched in 2004 and became FY2-04. FY2-E was launched in 2006 and became FY2-05. FY2-F was launched in 2008 and became FY2-06.

FENG-YUN-4

• Feng-Yun-4 will be China's second series of geostationary meteorological satellites. They are similar to the USA's GOES-13/15 3-axis stabilized satellites built by the Boeing Corp. in the USA.
• FY-4 plans for 3-axis stabilization, 14 channel imagery with 5-minute scans of China, a FTIR sounder, a lightning mapper, and a solar imager.
• As of 2009, the first "experimental" satellite will be FY-4A launched in 2014, with two "operational" satellites to follow in 2017 and 2019.
• The FY-4 imager is called the "Advanced Geosynchronous Radiation Imager" (AGRI), and resembles "Advanced Baseline Imager" (ABI) being constructed by the ITT Corp. for GOES-R/S. AGRI uses an off-axis telescope, two scan mirrors, 216 detectors in 14 spectral bands, and full-path on-orbit calibration.
  

  AGRI Specifications

  Channel	Band (microns)	Spatial Resolution (km)	Sensitivity	Application
  Visible & Near Infrared	0.45-0.49	1	S/N≥70	Aerosol
  	0.55-0.75	0.5-1	S/N≥200	Cloud, Fog
  	0.75-0.90	1	S/N≥200	Vegetation
  Shortwave Infrared	1.36-1.39	2	S/N≥200	Cirrus
  	1.58-1.64	2	S/N≥200	Cloud, Snow
  	2.10-2.35	2-4	S/N≥200	Cirrus, Aerosol
  Midwave Infrared	3.5-4.0 (high)	2	NEDT≤0.7K	Fire
  	3.5-4.0 (low)	4	NEDT≤0.2K	Land Surface
  Water Vapor	5.8-6.7	4	NEDT≤0.3K	Water Vapor
  	6.9-7.3	4	NEDT≤0.3K	Water Vapor
  Longwave Infrared	8.0-9.0	4	NEDT≤0.2K	Water Vapor, Cloud
  	10.3-11.3	4	NEDT≤0.2K	Sea Surface Temperature
  	11.5-12.5	4	NEDT≤0.2K	Sea Surface Temperature
  	13.2-13.8	4	NEDT≤0.2K	Cloud, Water Vapor

  
  Notes: S/N is specified at 100% albedo, NEDT is specified at 300K, except for the two water vapor channels, which are specified at 260K.

• The FY-4 sounder is called the "Geosynchronous Interferometric Infrared Sounder" (GIIRS), and resembles the sounder proposed for GOES-R/S.
• GIIRS uses an optical design similar to AGRI, with 16x16 detectors arrays and active cooling.
  

  GIIRS Specifications

  	R&D	OPERATIONAL
  Spectral Parameters (cm-1)	LWIR: 700-1130@0.8, 538 ch. S/MIR: 1650-2250@1.6, 375 ch.	LWIR: 700-1130@0.625, 688 ch. S/MIR: 1650-2250@1.2, 500 ch.
  Spatial Resolution	16 km (448 microrad)	8 km (224 microrad)
  Operational Modes	China (5000x5000 km) Mesoscale (1000x1000 km)	China (5000x5000 km) Mesoscale (1000x1000 km)
  Temporal Resolution	China (1.0 hr) Mesoscale (0.5 hr)	China (<1.0 hr) Mesoscale (<0.5 hr)
  Sensitivity (mW/m^2 sr cm-1)	LWIR = 0.5, S/MIR= 0.1	LWIR = 0.3, S/MIR= 0.06
  Calibration Accuracy of Radiation (3 sigma)	1.5K	1.0K
  Calibration Accuracy of Spectrum (3 sigma)	10 ppm	5 ppm
  Quantization (bits)	13	13

• China plans to have hyperspectral interferometric sounders on both their geosynchronous (FY-4s) and polar-orbiting (FY-3s) satellites by 2015.

GOMS

• GOMS-1 GOMS is Russia's first geosynchronous weather imaging satellite, a 3-axis stabilized bird operated at 77E.

  The Scanning Television Radiometer (STR) on GOMS-1 has two spectral channels:

  • a visible (0.47-0.70 micron) channel with 1.25 km spatial resolution
  • a thermal infrared (10.5-12.5) channel with 6.25 km spatial resolution.
  Images can be scanned in 15 minutes, but the operational mode is 30 minute intervals. Pixels are downlinked in 8-bit words.

  GOMS-1 initially had serious problems after launch on 31 October 1994, but the controllers eventually managed to bring it on-line. Despite the problems, GOMS-1 has become operational for the Eastern Hemisphere, but visible imagery can't be broadcast because of problems with the sensor package.

  GOMS-1 infrared data became operational in June 1996. GOMS IR images are posted on-line, and a GOMS data archive is also on-line.

• GOMS historical items
  • Here is an early full-earth 11 micron image dated 28 February 1995 that was been presented to the WMO.
  • There have been some public descriptions of GOMS, such as a 1990 description of the key features and a 1995 post-launch blurb.
• GOMS-1 WEFAX
  • GOMS WEFAX downlink

    26 June 1996
    GOMS/ELEKTRO WEFAX FORMAT as for METEOSAT WEFAX
    
            3 second 300Hz Start signal
            5 seconds phasing signal 5% black, 95% white lines
            about 800 lines of image each with line start signal 
            (7 cycles of 840 Hz in blanking period) 
            Image content   : GOMS IR full earth disk + 4 quadrants
                            : METEOSAT IR full earth disk
                            : GMS IR 4 quadrants
                            : meteorological charts (not seen here, see note)
            3 seconds 450 Hz stop signal.
            RF characteristics
            Frequency : 1691.0 MHz
            EIRP:  +? dBW
            Modulation: AM/FM
            Baseband video frequency : ? 1600 Hz
            Mod index: ? 80%
            Sub-carrier  freq : 2400 Hz
            Freq Dev : ? 9 KHz
            RF bandwidth : 26 KHz
    
            Position : 76 degrees East
    
            ? is best guess or unknown, can anyone fill in the blanks ?
    
    GOMS DIGITAL DATA FORMAT
    
            Date rate : 1200 bps
            Modulation ? (PCM(SPILT PHASE-LEVEL)/PM)
            Mod index : ? (1.2 radian)
            RF bandwidth : ?
            Data Format : ?
    
    Note :  See "06Z 23/6/96 surface analysis chart" at URL 
            "http://www.drig.com/~johnb/gomsfax.gif "
            but beware, it is big (424 Kbytes !!!)
            (Credit : Chris van Lint and John Boyer)
    --
    Mike Kenny
    (m.kenny@bom.gov.au)
    Satellite Engingeering, Bureau of Meteorology, Melbourne, Australia.
    

  • GOMS WEFAX schedule

    Subject: GOMS Schedule
    From: "Donald E. Hinsman" <hinsman@www.wmo.ch>
    Date: Wed, 03 Jul 1996 14:27:06 +0100
    
    The following information was provided to WMO by the Russian Federation at
    the 48th WMO Executive Council.
    
    The following is the satellite data broadcasting schedule for GOMS N-1
    WEFAX channel No. 1 via the Obninsk information reception and transmission
    station (on 1691 MHz) (Time in UTC) (SSP 76 degrees east longitude)
    
    Certified by Mr A. B. Uspensky, May 1996
    Director-General of Planeta, a scientific production company
    
                          Hour
           03.00   04.00   15.00   16.00   17.00   Comments
    Min.
    
    :02            W0              W0      M4      Retransmission of other 
                                                   Meteosat WEFAX formats 
                                                   is possible
    :06            W1              W1
    :10            W2              W2
    :14    DTOT    W3              W3      M5
    :18    ETOT    W4      DTOT    W4
    :22                    CTOT
    :26    GMSA    M1      GMSA    M1      M6
    :30
    :34
    :38            M2              M2      W0
    :42                                    W1
    :46                                    W2
    :50    GMSB    M3              M3      W3
    :54                                    W4
    :58
    
    Where
    
    DTOT   Standard Meteosat WEFAX format
    ETOT   Standard Meteosat WEFAX format
    CTOT   Standard Meteosat WEFAX format
    GMSA   Standard Meteosat WEFAX format
    GMSB   Standard Meteosat WEFAX format
    
    W0     Standard GOMS N-1 WEFAX format
    W1     Standard GOMS N-1 WEFAX format
    W2     Standard GOMS N-1 WEFAX format
    W3     Standard GOMS N-1 WEFAX format
    W4     Standard GOMS N-1 WEFAX format
    
    Mn  Frames with Meteor TV information
    M1  Part of Europe sector (direct transmission mode)
    M2  Parts of the western Indian Ocean and Africa
    M3  Parts of the western Indian Ocean and Africa
    M4  Parts of the western Indian Ocean and Africa
    M5  Parts of the Arctic Eurasian coast (the Northern Passage -  Sevmorput)
    M6  Parts of the Arctic Eurasian coast (the Northern Passage -  Sevmorput)
    
    and 
    
    W0 Full disk IR
    W1 NW quadrant IR
    W2 NE quadrant IR
    W3 SW quadrant IR
    W4 SE quadrant IR
    
    
    _________________________________________________
    Dr Donald Hinsman       tel: + 41 22 730 8285
    41, av Giuseppe-Motta   fax: + 41 22 734 2326
    PO Box 2300             email: hinsman@www.wmo.ch
    CH-1211 Geneva 2, Switzerland
    _________________________________________________
    

• The imager on GOMS-2 will carry a third channel: infrared water vapor (0.6-0.7 micron). As of November 2003, GOMS-Electro-N2 is scheduled for launch in 2005-6, to be positioned at 76E.
• The GOMS satellites have a 3-year design life.

ELECTRO-L

• The next generation of Russian geosynchronous satellites are generically named ELEKTRO-L. They will be 3-axis stabilized, with a 10 year design life, and carry a 10 channel imager capable of 15 to 30 minute repeat scans.
• As of 2006, the plan was to launch ELEKTRO-L1/2/3 in 2007/10/15. As of 2009, the plan was to launch ELEKTRO-L1/2 in 2010/11.
• ELEKTRO-L1 was launched in January 2011.
• The first published full-disk image was taken on 26 Feb. 2011, at 14:30 Moscow time.
  
• The visible/infrared imaging instrument is called the "Multichannel Scanning Unit" (MSU or MSU-GS). It will carry 3 visible (reflected sunlight) channels, and 7 infrared channels:

INSAT

• INSAT is a series of 3-axis stabilized geosynchronous satellites operated by the Indian Space Research Organisation (ISRO), primarily as communications birds. INSATs are built as a group of similar satellites in a series, roughly one series per decade, so there have been INSAT-1's (1980's), INSAT-2's (1990's), and INSAT-3's (2000's). The satellites in each series are designated A, B, C, etc.. Typically, one of the later INSAT satellites in each series carries a meteorological imager.
• The data from the meteorological imager on INSAT is sent to the India Meteorological Department (IMD), which posts recent thumbnail images from INSAT.
• THE INSAT-1 SERIES
  • INSAT-1D was a 3-axis stabilized communications bird launched in 1990 carrying a Very High Resolution Radiometer (VHRR). In 1999, it was temporarily retired from imagery and moved to 74E longitude, with 1.5 degrees inclination.
    The VHRR has two spectral channels:
    • a visible (0.47-0.70 micron) channel with 2 km spatial resolution
    • a thermal infrared (10.5-12.5) channel with 8 km spatial resolution.
    Full disk images can be scanned in 30 minutes, and smaller sectors more rapidly.
• THE INSAT-2 SERIES
  • INSAT-2B has an inclined orbit at 111 E, and is listed as a backup satellite.
  • INSAT-2C is at 48 E.
  • INSAT-2D is at 55 E.
  • INSAT-2E has a meteorological imaging payload, with an additional water vapour window (5.7-7.1 microns) and a 3-band CCD. Launched on 3 April 1999, and located at 83E longitude, INSAT-2E replaced INSAT-1D.
    First visible image from INSAT-2E.
    However, late in 1999, the new imager on INSAT-2E was failing, and INSAT-1D was pressed back into service, which functioned intermittantly until mid-May 2002, when INSAT-2E was pressed back into service at 83E.
• THE INSAT-3 SERIES
  • During 2002 to 2006, ISRO plans to build and launch six geosynchronous satellites: one stop-gap METSAT, and five INSATs, INSAT-3A through INSAT-3E. While INSAT-3A to -3D are expected to weigh around 2.5 tons each, INSAT-3E will be 3.5 tons. The INSAT-3A, -3B and -3C satellites would augment the INSAT-2 transponder capacity to about 130 transponders by 2002. The launch of the heavy INSAT-3 series depended upon the successful development of ISRO's geosynchronous launch vehicle.
    • GSAT-1 was a light-weight, inexpensive stop-gap satellite carrying a VHRR. GSAT-1 was launched in September 2002 using a modified version of ISRO's polar satellite launch vehicle. However, GSAT-1 failed to make geosynchronous orbit due to problems with the final booster. GSAT-1 was to provide basic imagery in the early 2000's, before the INSAT-3 series could be launched.
    • INSAT-3A carries a basic meteorologial package: a 3 channel VHRR and a 3 -band CCD. INSAT-3A was launched in April 2003, declared operational after a few weeks, and positioned at 89E.
    • INSAT-3B is operational in 2003.
    • INSAT-3C is operational in 2003.
    • INSAT-3D is expected to carry an advanced six channel VHRR imager and a 19-channel sounder, besides 10 Ku band channels. As of early 2006, INSAT-3D is scheduled for launch in 2007.
    • INSAT-3E will be a heavier satellite with a different upgraded bus, capable of carrying 20 Ku band channels.
• THE INSAT-4 SERIES
  • According to the ISRO's annual report for 2005, the INSAT-4 series will carry a larger number of Ku-band transponders to improve service for users of small aperture terminals in India. From 2005 to 2009, the INSAT communications system is expected to grow from 102 transponders to 251 in various frequency bands.
  • INSAT-4B was launched on an Ariane-5 in December 2005.
  • INSAT-4B is scheduled to be launched on an Ariane-5 in 2007.
  • INSAT-4C was lost in a launch failure of India's new heavy-lift vehicle, the Geosynchronous Satellite Launch Vehicle (GSLV) in July 2006.
• METSAT aka KALPANA-1
  • METSAT, India's first exclusively meteorological satellite, was launched on 12 September 2002. It was renamed KALPANA-1, and is positioned at 74 E, co-located with INSAT-3C.
  • The KALPANA-1 scanning imager has 2 km visible resolution and 8 km infrared resolution in a window and water vapor band, like INSAT-3A.
• In the mid-1990's, INSAT imagery was encrypted to hide it from the surrounding nations, leaving a major gap in real time global cloud coverage. An agreement was signed in late 1997 by NASA, NOAA, and the Indian government for western access to real time INSAT data, and data began flowing by mid-1999.
  These publicly available INSAT images are at least 3 days old, in accordance with the agreement with India not to distribute real time INSAT data. Even then, these images are restricted to use by the employees of NASA and NOAA, and to their contract employees, including univerities engaged in NASA-funded or NOAA-funded research.

COMS

• In 2005, Korea contracted with EADS Astrium for a 3-axis stabilized Ka-band communication satellite.
• COMS will carry a 5-channel Meteorological Imager (MI), with 1 km VIS resolution and 4 km IR resolution. The instrument will be built by ITT, the same company that built the GOES Imagers.
  

  MI Requirements

  Channel	Spectral band (microns)	Application
  Visible	0.675	Daytime cloud imagery Detection of special event (yellow dust, fire, haze, etc.) Atmospheric motion vector
  Shortwave IR	3.75	Nighttime fog/stratus Fire detection Surface temperature
  Water Vapor	6.75	Upper atmospheric water vapor Upper atmospheric motion
  Longwave Window 1	10.8	Standard IR split window channel (Cloud, Sea surface temperature, Yellow sand detection)
  Longwave Window 2	12.0	Standard IR split window channel (Cloud, Sea surface temperature, Yellow sand detection)

• COMS will also carry an 8-band Geostationary Ocean Color Imager (GOCI) that provides hourly coverage of a 2500 km square area at 500 m resolution.

  GOCI Requirements

  Band center (nm)	Band width (nm)	Nominal radiance (Wm-2μm-1sr-1)	Maximum radiance (Wm-2μm-1sr-1)	NEdL (Wm-2μm-1sr-1)	Signal/Noise ratio
  412	20	100.0	150.0	0.100	1000
  443	20	92.5	145.8	0.085	1090
  490	20	72.2	115.5	0.067	1170
  555	20	55.3	85.2	0.056	1070
  660	20	32.0	58.3	0.032	1010
  680	10	27.1	46.2	0.031	870
  745	20	17.7	33.0	0.020	860
  865	40	12.0	23.4	0.016	750

• As of early 2006, COMS was to be launched at the end of 2008 and stationed at 116.2E or 128.2E longitude, depending on the ITU communications slot allocation.
• As of late 2006, COMS-1 was to be placed into geostationary transfer orbit by an Ariane 5 from the Guiana Space Center, Europe's Spaceport in Kourou, French Guiana, between the end of 2008 and June 2009.
• As of late 2009, COMS-1 was to be launched late in 2010, and plans for COMS-2 to be launched in 2016 were begun.
• On 27 June 2010, COMS-1 was launched from Kourou.
• Seoul spent more than 354.9 billion won (US$295.4 million) and took eight years to build the 2.5 ton high-tech satellite that is designed to be in operation for seven years.
• Users will get rebroadcast COMSdata in LRIT/HRIT format.

PCW

• In 2009, The Canadian Space Agency was examining the feasibility of flying a weather-imaging instrument on communications satellites in highly inclined "bi-geosynchronous" (twice-a-day) orbits, of the kind long used by the Russian Molniya communications satellites.
• A Molniya orbit is highly elliptical with an inclination of 63.4 degrees and an orbital period of about 12 hours, with apogee at 39,500 km (over the Arctic) and perigee at 600 km (over the Antarctic). A satellite placed in a Molniya orbit spends most of its time over the high latitudes as a result of "apogee dwell". The polar cap is visible to the satellite for 8 out of 12 hours, so a pair of such satellites can provide continuous communications and weather imaging to all the northern latitudes.
• The area north of 60 degrees is one-sixth of the northern hemisphere, but cloud- and water vapor-tracked winds are not visible to the geosynchronous satellites over the equator. Experiments have shown that such satellite-based wind estimates can significantly improve medium-range forecasts, particularly for avoiding "busted forecasts" due to the surprise emergence of a polar storm into mid-latitudes. Real time observations are needed for weather "nowcasts" to route aircraft efficiently over the pole, as well as for timely assimilation into numerical weather forecast models.
• As of 2009, Canada is considering a high-resolution, multi-channel, 15-minute refresh imager with many of the characteristics of the "Advanced Baseline Imager" (ABI), which was under construction at that time for the USA's GOES-R/S mission.
  

  PCW Imager Options

  Wavelength (microns)	Heritage	Goal spatial resolution (km)	Minimum spatial resolution (km)	Priority 1=high	Main Applications
  0.45-0.49	ABI-01	1	2	2	Surface
  0.5-0.6	MODIS-04	0.5	1	2	Vegetation
  0.59-0.69	ABI-02	0.5	1	1	Wind, Clouds
  0.85-0.89	ABI-03	1	2	1	Wind, Aerosols, Vegetation
  1.37-1.39	ABI-04	1	4	2	Cirrus
  1.58-1.64	ABI-05	1	2	1	Snow-cloud distinction
  2.22-2.28	ABI-06	2	4	2	Cloud phase
  3.80-4.00	ABI-07	2	4	1	Fog/ fire detection, Ice/cloud separation, Wind
  5.77-6.60	ABI-08	2	4	2	Wind, Humidity
  6.75-7.15	ABI-09	2	4	1	Wind, Humidity
  7.24-7.44	ABI-10	2	4	1	Wind, Humidity
  8.30-8.70	ABI-11	2	4	2	Total water
  9.42-9.80	ABI-12	2	4	2	Total ozone
  10.1-10.6	ABI-13	2	4	2	Cloud, Surface
  10.8-11.6	ABI-14	2	4	1	Cloud, SST, Ash
  11.8-12.8	ABI-15	2	4	1	Ash, SST
  13.0-13.6	ABI-16	2	4	2	Cloud height
  13.5-13.8	MODIS-34	2	8	2	Cloud height
  13.8-14.1	MODIS-35	2	8	2	Cloud height
  14.1-14.4	MODIS-36	2	8	2	Cloud height