@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix ns0: <http://gcmd.gsfc.nasa.gov/kms#> .

<https://gcmd.earthdata.nasa.gov/kms/concept/ba611e74-27eb-4e97-a132-79d63f5e892b>
  skos:changeNote """2019-02-22 12:28:05.0 [mmorahan]  
insert AltLabel (id: null
category: null
text: SeaWinds
language code: en); 
update Resource (image); 
""", """2020-01-31 17:35:04.0 [sritz]  
update Definition (The SeaWinds scatterometer is a specialized microwave radar that measures near-surface wind velocity (both speed and direction)
under all weather and cloud conditions over Earth's oceans. The experiment is a follow-on mission and continues the data 
series initiated in 1996 by the NASA scatterometer (NSCAT).  The SeaWinds instrument was launched on the NASA QuikScat "quick 
recovery" satellite on June 19, 1999.  SeaWinds was also launched on the Japan Aerospace Exploration Agency (JAXA) Advanced 
Earth Observation Satellite II (ADEOS-II) on December 14, 2002. ADEOS-II failed on October 24, 2003.

SeaWinds uses a rotating dish antenna with two spot beams that sweep in a circular pattern. The antenna radiates microwave 
pulses at a frequency of 13.4 gigahertz across broad regions on Earth's surface. The instrument will collect data over ocean, 
land, and ice in a continuous, 1,800-kilometer-wide band, making approximately 400,000 measurements and covering 90% of 
Earth's surface in one day.

Scatterometers use a highly indirect technique to measure wind velocity over the ocean. Changes in the wind velocity cause 
changes in ocean surface roughness, modifying the radar cross section of the ocean and the magnitude of the backscattered 
power. Multiple collocated measurements acquired from several viewing geometries (incidence angles, polarizations, and 
directions) are used to determine wind speed and direction simultaneously. The directly measured backscatter cross-sections 
over land and ice-covered regions yield information on vegetation type and ice type and extent.

Key SeaWinds Facts
Heritage: SeaSat, NSCAT
Dimensions: CDS: 32 cm ? 46 cm ? 34 cm; SES: 81 cm ? 91 cm ? 43 cm;
SAS: ~150 cm; 100-cm diameter antenna dish on 60-cm diameter ? 60-cm pedestal
Mass: 220 kg
Power: 220 W
Duty Cycle: 100%
Thermal Control: Radiators
Thermal Operating Range: 5\\–40Ú C
Field of View (FOV): Rotating (at 18 rpm) pencil-beam antenna with dual feeds pointing 40Ú and 46Ú from nadir
IFOV: ? 51Ú from nadir
Swath: 1800 km (? 51Ú look angles) from 803-km altitude
Pointing Requirements (3Ã): Control: <0.3Ú (~1000 arcsec); Knowledge: <0.05Ú (~167 arcsec); Stability: <0.008Ú/s (30 arcsec/s)


Group: Instrument_Details
   Entry_ID: SEAWINDS
   Group: Instrument_Identification
      Instrument_Category: Earth Remote Sensing Instruments
      Instrument_Class: Active Remote Sensing
      Instrument_Type: Scatterometers
      Short_Name: SEAWINDS
      Long_Name: SeaWinds
   End_Group
   Group: Associated_Platforms
      Short_Name: QUIKSCAT
      Short_Name: ADEOS-II
   End_Group
   Group: Spectral_Frequency_Information
      Wavelength_Keyword: Microwave
      Spectral_Frequency_Coverage_Range: 13.4 gigahertz; 110-watt pulse at 189-hertz pulse repetition frequency (PRF)
   End_Group
   Online_Resource: https://www.jpl.nasa.gov/missions/seawinds/
   Online_Resource: https://winds.jpl.nasa.gov/
   Online_Resource: https://winds.jpl.nasa.gov/missions/quikscat/index.cfm
   Online_Resource: https://winds.jpl.nasa.gov/missions/seawinds/index.cfm
   Creation_Date: 2007-04-16
   Group: Instrument_Logistics
      Data_Rate: 40 kbps
      Instrument_Start_Date: 1999-07-19
      Instrument_Owner: USA/NASA
   End_Group
   Group: Instrument_Logistics
      Data_Rate: 40 kbps
      Instrument_Start_Date: 2003-04-10
      Instrument_Stop_Date: 2003-10-24
      Instrument_Owner: USA/NASA
   End_Group
End_Group); 
update Definition (https://winds.jpl.nasa.gov/); 
delete Resource (null); 
""" ;
  ns0:altLabel [ ] ;
  skos:definition """The SeaWinds scatterometer is a specialized microwave radar that measures near-surface wind velocity (both speed and direction)
under all weather and cloud conditions over Earth's oceans. The experiment is a follow-on mission and continues the data 
series initiated in 1996 by the NASA scatterometer (NSCAT).  The SeaWinds instrument was launched on the NASA QuikScat "quick 
recovery" satellite on June 19, 1999.  SeaWinds was also launched on the Japan Aerospace Exploration Agency (JAXA) Advanced 
Earth Observation Satellite II (ADEOS-II) on December 14, 2002. ADEOS-II failed on October 24, 2003.

SeaWinds uses a rotating dish antenna with two spot beams that sweep in a circular pattern. The antenna radiates microwave 
pulses at a frequency of 13.4 gigahertz across broad regions on Earth's surface. The instrument will collect data over ocean, 
land, and ice in a continuous, 1,800-kilometer-wide band, making approximately 400,000 measurements and covering 90% of 
Earth's surface in one day.

Scatterometers use a highly indirect technique to measure wind velocity over the ocean. Changes in the wind velocity cause 
changes in ocean surface roughness, modifying the radar cross section of the ocean and the magnitude of the backscattered 
power. Multiple collocated measurements acquired from several viewing geometries (incidence angles, polarizations, and 
directions) are used to determine wind speed and direction simultaneously. The directly measured backscatter cross-sections 
over land and ice-covered regions yield information on vegetation type and ice type and extent.

Key SeaWinds Facts
Heritage: SeaSat, NSCAT
Dimensions: CDS: 32 cm ? 46 cm ? 34 cm; SES: 81 cm ? 91 cm ? 43 cm;
SAS: ~150 cm; 100-cm diameter antenna dish on 60-cm diameter ? 60-cm pedestal
Mass: 220 kg
Power: 220 W
Duty Cycle: 100%
Thermal Control: Radiators
Thermal Operating Range: 5\\–40Ú C
Field of View (FOV): Rotating (at 18 rpm) pencil-beam antenna with dual feeds pointing 40Ú and 46Ú from nadir
IFOV: ? 51Ú from nadir
Swath: 1800 km (? 51Ú look angles) from 803-km altitude
Pointing Requirements (3Ã): Control: <0.3Ú (~1000 arcsec); Knowledge: <0.05Ú (~167 arcsec); Stability: <0.008Ú/s (30 arcsec/s)


Group: Instrument_Details
   Entry_ID: SEAWINDS
   Group: Instrument_Identification
      Instrument_Category: Earth Remote Sensing Instruments
      Instrument_Class: Active Remote Sensing
      Instrument_Type: Scatterometers
      Short_Name: SEAWINDS
      Long_Name: SeaWinds
   End_Group
   Group: Associated_Platforms
      Short_Name: QUIKSCAT
      Short_Name: ADEOS-II
   End_Group
   Group: Spectral_Frequency_Information
      Wavelength_Keyword: Microwave
      Spectral_Frequency_Coverage_Range: 13.4 gigahertz; 110-watt pulse at 189-hertz pulse repetition frequency (PRF)
   End_Group
   Online_Resource: https://www.jpl.nasa.gov/missions/seawinds/
   Online_Resource: https://winds.jpl.nasa.gov/
   Online_Resource: https://winds.jpl.nasa.gov/missions/quikscat/index.cfm
   Online_Resource: https://winds.jpl.nasa.gov/missions/seawinds/index.cfm
   Creation_Date: 2007-04-16
   Group: Instrument_Logistics
      Data_Rate: 40 kbps
      Instrument_Start_Date: 1999-07-19
      Instrument_Owner: USA/NASA
   End_Group
   Group: Instrument_Logistics
      Data_Rate: 40 kbps
      Instrument_Start_Date: 2003-04-10
      Instrument_Stop_Date: 2003-10-24
      Instrument_Owner: USA/NASA
   End_Group
End_Group"""@en ;
  skos:altLabel "SeaWinds"@en ;
  skos:prefLabel "SEAWINDS"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/563f30c8-43f8-48be-b649-4b548f877fa4> ;
  a skos:Concept .

<https://gcmd.earthdata.nasa.gov/kms/concept/563f30c8-43f8-48be-b649-4b548f877fa4>
  skos:prefLabel "Scatterometers"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/ba611e74-27eb-4e97-a132-79d63f5e892b> .

