PDS_VERSION_ID                     = PDS3
RECORD_TYPE                        = STREAM
LABEL_REVISION_NOTE                = "2007-07-11 GEO:JGW;
                                      2010-04-06 GEO:JGW, updated;
                                      2011-04-19 Campbell, updates from peer 
                                      review."

OBJECT                             = INSTRUMENT
 INSTRUMENT_ID                     = "RTLS"
 INSTRUMENT_HOST_ID                = "ARCB"

 OBJECT                            = INSTRUMENT_INFORMATION
  INSTRUMENT_NAME                  = "RADIO TELESCOPE"
  INSTRUMENT_TYPE                  = RADAR
  INSTRUMENT_DESC                  = "

  Instrument Overview
  ===================
  
  The following information comes from the NAIC website
  (http://www.naic.edu/public/the_telescope.htm):
  
  The radio telescope at Arecibo Observatory, located in Arecibo, Puerto 
  Rico, is '305 m (1000 feet) in diameter, 167 feet deep, and covers an area 
  of about twenty acres. The surface is made of almost 40,000 perforated 
  aluminum panels, each measuring about 3 feet by 6 feet, supported by a 
  network of steel cables strung across the underlying karst sinkhole. It is 
  a spherical (not parabolic) reflector.
    
  Suspended 450 feet above the reflector is the 900 ton platform. Similar in 
  design to a bridge, it hangs in midair on eighteen cables, which are strung 
  from three reinforced concrete towers. One is 365 feet high, and the other
  two are 265 feet high. All three tops are at the same elevation. The
  combined volume of reinforced concrete in all three towers is 9,100 cubic
  yards. Each tower is back-guyed to ground anchors with seven 3.25 inch
  diameter steel bridge cables. Another system of three pairs of cables runs
  from each corner of the platform to large concrete blocks under the
  reflector. They are attached to giant jackswhich allow adjustment of the
  height of each corner with millimeter precision.

  Just below the triangular frame of the upper platform is a circular track 
  on which the azimuth arm turns. The azimuth arm is a bow shaped structure
  328 feet long. The curved part of the arm is another track, on which a
  carriage house on one side and the gregorian dome (installed in 1996) on
  the other side can be positioned anywhere up to twenty degrees from the
  vertical. Inside the gregorian dome two subreflectors (secondary and
  tertiary) focus radiation to a point in space where a set of horn antennae
  can be positioned to gather it.'

  The radar observations incorporated in this archive were produced by 
  transmitting a circular-polarized radio signal at 2380 MHz frequency 
  (12.6-cm wavelength) from the Arecibo Planetary Radar System. The typical 
  transmit power was 45-100 kilowatts. Circular polarization is routinely 
  used in planetary radar observations to avoid the complicating effects of 
  Faraday rotation in the Earth's ionosphere.

  See 'An Astronomer's Guide to the Arecibo 305-m Telescope' [SALTER2009] for
  more information.

  "

 END_OBJECT                        = INSTRUMENT_INFORMATION

 OBJECT                            = INSTRUMENT_REFERENCE_INFO
  REFERENCE_KEY_ID                 = "SALTER2009"
 END_OBJECT                        = INSTRUMENT_REFERENCE_INFO

END_OBJECT                         = INSTRUMENT
END