@prefix skos: . @prefix ns0: . skos:prefLabel "Imaging Spectrometers/Radiometers"@en ; a skos:Concept ; skos:narrower . skos:altLabel "SeaWiFS"@en ; skos:changeNote """2019-02-22 08:54:19.0 [mmorahan] update Resource (image); insert WeightedRelation (id: null related concept uuid: aef85316-b8f8-422a-add0-8130b113fa7d relationship type: null relationship value: null generated by: null); """, """2020-01-29 16:53:01.0 [sritz] insert AltLabel (id: null category: null text: SeaWiFS language code: en); """, """2020-01-29 16:57:11.0 [sritz] update Resource (https://oceancolor.gsfc.nasa.gov/SeaWiFS/SEASTAR/seawifs_bench.gif); """, """2020-01-29 16:52:03.0 [sritz] update Definition ([SeaWiFS collected data from September 1997 until the end of its mission in December 2010] The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September 1997 until the end of mission in December 2010. SeaWiFS had 8 spectral bands from 412 to 865 nm. It collected global data at 4 km resolution, and local data (limited onboard storage and direct broadcast) at 1 km. The mission and sensor were optimized for ocean color measurements, with a local noon (descending) equator crossing time orbit, fore-and-aft tilt capability, full dynamic range, and low polarization sensitivity. The SeaWiFS instrument has scanning mechanisms to drive an off-axis folded telescope and a rotating halfangle mirror. Incoming scene radiation is collected by the folded telescope and reflected onto the rotating half-angle mirror. The collected radiation is then relayed through dichroic beam splitters to separate the radiation into four wavelength intervals each wavelength interval encompassing two of the eight SeaWiFS spectral bands. Four corresponding aft-optics direct the radiation in the four separate wavelength intervals through two separate spectral band-pass filters that further separate the radiation into eight SeaWiFS spectral bands. The aft-optics assemblies also image each of the resultant defined bands of radiation onto four detectors that are aligned in the scan direction. Monitoring of sensor calibration over periods of a few orbits, to several months or years, is accomplished using solar calibration for the former and lunar calibration for the latter. Solar calibration uses a solar-radiation diffuser and an input port located in a fixed position outside of the 58.3 degree SeaWiFS scene-scan interval. Lunar calibration is accomplished by a spacecraft maneuver to view the moon when the spacecraft is in the nighttime portion of its orbit. Key SeaWiFS Facts Scan Width: 58.3 deg (LAC); 45.0 deg (GAC) Scan Coverage: 2,800 km (LAC); 1,500 km (GAC) Pixels along Scan: 1,285 (LAC); 248 (GAC) Nadir Resolution: 1.13 km (LAC); 4.5 km (GAC) Scan Period: 0.124 seconds Tilt: -20, 0, +20 deg Digitization: 10 bits (LAC stands for Local Area Coverage; GAC stands for Global Area Coverage) Additional Information: https://oceancolor.gsfc.nasa.gov/SeaWiFS/ Group: Instrument_Details Entry_ID: SEAWIFS Group: Instrument_Identification Instrument_Category: Earth Remote Sensing Instruments Instrument_Class: Passive Remote Sensing Instrument_Type: Spectrometers/Radiometers Instrument_Subtype: Imaging Spectrometers/Radiometers Short_Name: SEAWIFS Long_Name: Sea-Viewing Wide Field-of-View Sensor End_Group Group: Associated_Platforms Short_Name: SEASTAR End_Group Group: Spectral_Frequency_Information Wavelength_Keyword: Visible Number_Channels: 6 channels Spectral_Frequency_Coverage_Range: 0.4 - 0.7 micrometers End_Group Group: Spectral_Frequency_Information Wavelength_Keyword: Near Infrared Number_Channels: 2 channels Spectral_Frequency_Coverage_Range: 0.765 - 0.865 micrometers End_Group Online_Resource: https://oceancolor.gsfc.nasa.gov/SeaWiFS/ Online_Resource: https://oceancolor.gsfc.nasa.gov/data/seawifs/ Sample_Image: https://oceancolor.gsfc.nasa.gov/SeaWiFS/SEASTAR/seawifs_bench.gif Creation_Date: 2007-04-16 Group: Instrument_Logistics Instrument_Start_Date: 1997-09-01 Instrument_Stop_Date: 2010-12-11 Instrument_Owner: USA/NASA End_Group End_Group); """ ; skos:inScheme ; a skos:Concept ; skos:prefLabel "SEAWIFS"@en ; skos:definition """[SeaWiFS collected data from September 1997 until the end of its mission in December 2010] The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September 1997 until the end of mission in December 2010. SeaWiFS had 8 spectral bands from 412 to 865 nm. It collected global data at 4 km resolution, and local data (limited onboard storage and direct broadcast) at 1 km. The mission and sensor were optimized for ocean color measurements, with a local noon (descending) equator crossing time orbit, fore-and-aft tilt capability, full dynamic range, and low polarization sensitivity. The SeaWiFS instrument has scanning mechanisms to drive an off-axis folded telescope and a rotating halfangle mirror. Incoming scene radiation is collected by the folded telescope and reflected onto the rotating half-angle mirror. The collected radiation is then relayed through dichroic beam splitters to separate the radiation into four wavelength intervals each wavelength interval encompassing two of the eight SeaWiFS spectral bands. Four corresponding aft-optics direct the radiation in the four separate wavelength intervals through two separate spectral band-pass filters that further separate the radiation into eight SeaWiFS spectral bands. The aft-optics assemblies also image each of the resultant defined bands of radiation onto four detectors that are aligned in the scan direction. Monitoring of sensor calibration over periods of a few orbits, to several months or years, is accomplished using solar calibration for the former and lunar calibration for the latter. Solar calibration uses a solar-radiation diffuser and an input port located in a fixed position outside of the 58.3 degree SeaWiFS scene-scan interval. Lunar calibration is accomplished by a spacecraft maneuver to view the moon when the spacecraft is in the nighttime portion of its orbit. Key SeaWiFS Facts Scan Width: 58.3 deg (LAC); 45.0 deg (GAC) Scan Coverage: 2,800 km (LAC); 1,500 km (GAC) Pixels along Scan: 1,285 (LAC); 248 (GAC) Nadir Resolution: 1.13 km (LAC); 4.5 km (GAC) Scan Period: 0.124 seconds Tilt: -20, 0, +20 deg Digitization: 10 bits (LAC stands for Local Area Coverage; GAC stands for Global Area Coverage) Additional Information: https://oceancolor.gsfc.nasa.gov/SeaWiFS/ Group: Instrument_Details Entry_ID: SEAWIFS Group: Instrument_Identification Instrument_Category: Earth Remote Sensing Instruments Instrument_Class: Passive Remote Sensing Instrument_Type: Spectrometers/Radiometers Instrument_Subtype: Imaging Spectrometers/Radiometers Short_Name: SEAWIFS Long_Name: Sea-Viewing Wide Field-of-View Sensor End_Group Group: Associated_Platforms Short_Name: SEASTAR End_Group Group: Spectral_Frequency_Information Wavelength_Keyword: Visible Number_Channels: 6 channels Spectral_Frequency_Coverage_Range: 0.4 - 0.7 micrometers End_Group Group: Spectral_Frequency_Information Wavelength_Keyword: Near Infrared Number_Channels: 2 channels Spectral_Frequency_Coverage_Range: 0.765 - 0.865 micrometers End_Group Online_Resource: https://oceancolor.gsfc.nasa.gov/SeaWiFS/ Online_Resource: https://oceancolor.gsfc.nasa.gov/data/seawifs/ Sample_Image: https://oceancolor.gsfc.nasa.gov/SeaWiFS/SEASTAR/seawifs_bench.gif Creation_Date: 2007-04-16 Group: Instrument_Logistics Instrument_Start_Date: 1997-09-01 Instrument_Stop_Date: 2010-12-11 Instrument_Owner: USA/NASA End_Group End_Group"""@en ; skos:broader ; ns0:altLabel [ ] ; ns0:resource [ ] .