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  <Identification_Area>
    <logical_identifier>urn:nasa:pds:a12sws_solar_wind_28s_1hr:document:a12_solar_ephemeris</logical_identifier>
    <version_id>1.0</version_id>
    <title>Apollo 12 SWS Site - Solar Ephemeris</title>
    <information_model_version>1.23.0.0</information_model_version>
    <product_class>Product_Document</product_class>
    <Citation_Information>
      <publication_year>2025</publication_year>
      <description>The Solar Ephemeris file provides the local          
        position of the Sun at the site of the Apollo 12 SWS instrument           
        (336.58 East Longitude, 3.01 South Latitude).  The ephemeris data were    
        calculated at hourly intervals, beginning at 1969-Nov-18 00:00 and        
        ending at 1976-Mar-26 00:00 Universal Time Coordinated (UTC).             
        The columns are:                                                          
        
        - Date (yyy-mmm-dd) in UTC,                                             
        - Time in hours:minutes in UTC,                                         
        - Apparent solar azimuth angle in degrees (north=0, east=90),           
        - Apparent solar elevation angle in degrees with respect to a plane     
        perpendicular to the local zenith where a negative sign means the     
        Sun is below the plane horizon and 90 degrees is vertical,            
        - Change in solar azimuth with time multiplied by the cosine of         
        the elevation in arcseconds per minute, and                           
        - Change in solar elevation with time in arcseconds per minute.         
        
        Local topography is not taken into account, typically the local sunrise   
        and sunset will be offset by a few hours from the zero solar elevation    
        values because of surrounding landforms.  The table was generated by      
        the Horizons On-Line Ephemeris System at the Jet Propulsion Laboratory    
        (http://ssd.jpl.nasa.gov/).</description>
    </Citation_Information>
    <Modification_History>
      <Modification_Detail>
        <modification_date>2025-09-26</modification_date>
        <version_id>1.0</version_id>
        <description>Initial version.</description>
      </Modification_Detail>
    </Modification_History>
  </Identification_Area>
  <Context_Area>
    <Time_Coordinates>
      <start_date_time>1969-11-18T00:00:00Z</start_date_time>
      <stop_date_time>1976-03-26T00:00:00Z</stop_date_time>
    </Time_Coordinates>
    <Investigation_Area>
      <name>Apollo 12</name>
      <type>Mission</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:investigation:mission.apollo_12</lid_reference>
        <reference_type>document_to_investigation</reference_type>
      </Internal_Reference>
    </Investigation_Area>
    <Observing_System>
      <Observing_System_Component>
        <name>The Apollo 12 Lunar Surface Experiments Package</name>
        <type>Host</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument_host:spacecraft.a12a</lid_reference>
          <reference_type>is_instrument_host</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
      <Observing_System_Component>
        <name>Apollo 12 Lunar Surface Experiments Package Solar Wind Spectrometer</name>
        <type>Instrument</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument:sws.a12a</lid_reference>
          <reference_type>is_instrument</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
    </Observing_System>
    <Target_Identification>
      <name>Moon</name>
      <type>Satellite</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:target:satellite.earth.moon</lid_reference>
        <reference_type>document_to_target</reference_type>
      </Internal_Reference>
    </Target_Identification>
  </Context_Area> 
  <Document>
    <publication_date>2008-07-24</publication_date>
    <Document_Edition>
      <edition_name>7-Bit ASCII Text version</edition_name>
      <language>English</language>
      <files>1</files>
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