A 32 m INTELSAT Antenna in the Peruvian Andes

 to be Converted into a Radio Astronomy Facility

Japanese / Spanish

Antenna Site at 3,300 m
The antenna station in Huancayo, Peru

Introduction
By adding a station in southern hemisphere like Peru, a marvelous improvement in u-v coverage could be obtained with the VLBA for sources near equator.  Currently a plan is being developed to convert a 32-m telecommunications antenna used for INTELSAT in the Peruvian Andes into a radio astronomy facility operated by the Institute of Geophysics in Peru (IGP) and local universities with assistance from the National Astronomical Observatory of Japan (NAOJ).
Initially, the antenna will be tuned to receive Methyl Alcohol spectral lines at 6.7 GHz to survey and monitor Young Stellar Objects by smaller modifications from the present system.  As the surface accuracy of the main dish is better, observations at higher frequencies could be expected in the future.  On the other hand since the antenna location is unique in the southern hemisphere, geodetic observations at S/X band should be done to measure plate tectonics in South America.

Location
The Sicaya antenna station is located on a small hill in a beautiful open flat valley that is similar to Owens Valley in California or Nobeyama in Japan where world famous radio observatories are located.  The Huancayo observatory of IGP is just 5 km away from the Sicaya antenna station.  The antenna looks still in very good condition without no apparent rust probably due to its location at 3370 m of high altitude and being far away from sea side.  The structure of the antenna is well suited to upgrade receivers in future.  The receiver room is on the ground floor and connected with the main antenna dish and sub reflector with a beam transfer reflector guide system.  That allows us to install the receivers on the ground floor and to work on these easily.  Here is detail of the antenna that we got from the Japanese company NEC who made it:

    Latitude: -12‹02f15h, Longitude: -75‹17f39h
    Altitude: 3,370 m.
    Built year: 1984 to 1985
    Antenna type: Cassegrain system
    Diameter of main dish: 105 ft (32m)
    Frequency band: 6 GHz (transmission), 4 GHz (reception)
    Antenna mount: Wheel Track type AZ-EL mount
    Antenna moving speed: 0.3 degree/s for both AZ and EL
    Surface accuracy:  1.09 mm rms (without wind),
                               1.26 mm rms (with 13 m/s wind)

Conclusion
The advantage of the addition of the Sicaya 32-m telescope in the Peruvian Andes to the VLBA is remarkable especially for low declination and southern declination sources.  Discussions are now taking place to investigate how to upgrade this telescope so that both single dish and VLBI observations can be undertaken.  However we believe that joining VLBA for VLBI observations is one of the most exciting aspects of the project.  Geodetic measurements of plate tectonics in the active Andes region will be useful for geophysics and earth rotation sciences, and it would be also a great contribution for the development of sciences in Peru.

References:
- gPotential Improvements to VLBA uv-Coverages by the Addition of a 32m Peruvian Antennah, 2003, Future Directions in High Resolution Astronomy, A Celebration of the 10th Anniversary of the VLBA, Socorro, New Mexico, USA. (Poster in ppt format)(1 MB)


Links:
                              - Astronomical Society of Japan Meeting - 2004a          
Under Construction/Last update April 2007.