The Arecibo Observatory and its Telescope

The Arecibo Observatory (AO) is part of the National Astronomy and Ionosphere Center (NAIC), which is operated by SRI International under a cooperative agreement with the National Science Foundation (AST-1100968), and in alliance with Ana G. Méndez-Universidad Metropolitana, and the Universities Space Research Association. Use of the AO is available on an equal, competitive basis to all scientists from throughout the world to pursue research in radio astronomy, radar astronomy and atmospheric sciences. Observing time is granted on the basis of the most promising research as adjudicated by a panel of anonymous referees.

Table: Basic Information on the AO Site and the 305-m Telescope
      Longitude (Geodetic) 66$^{\circ}$45$^{\prime}$11.1 $^{\prime\prime}$ W
      Latitude 18$^{\circ}$20$^{\prime}$36.6 $^{\prime\prime}$ N
      Elevation of reflector center of curvature 497 m (1630 ft) above MSL
      Primary Reflector  
            Diameter of Spherical cap   305 m (1000 ft)
            Radius of Curvature 265 m (870 ft)
            Illuminated Area (at zenith):  
                 Gregorian Feeds $213 \times 237$ m ( $700 \times 776$ ft)
                 430-MHz Line Feed 305 m (1000 ft)
            Surface Accuracy 2 mm (rms)
      Frequency range 300 MHz $< \nu <$ 10 GHz (Gregorian)
      Wavelength range    1 m $> \lambda >$ 3 cm (Gregorian)
      Slew Rates:  
            Azimuth 24$^{\circ}$/min
            Zenith Angle 2$^{\circ}\!\!$.4/min
      Pointing Limits:  
            Azimuth 0$^{\circ}$-720$^{\circ}$
            Zenith Angle 0$^{\circ}$-19$^{\circ}\!\!$.7
  (1$^{\circ}\!\!$.06 -19$^{\circ}\!\!$.7 in tracking mode)
            Declination range $-1^{\circ}20^{\prime} < {\rm Dec} <
      Pointing Accuracy $\sim$5 $^{\prime\prime}$ (rms)

The Observatory lies in the karst hills of the Caribbean island of Puerto Rico, some 10 miles south of the coastal city of Arecibo. It was constructed in 1960-63 and upgraded, first in 1972-74, and again in 1992-98. Table 1 lists basic information on the observatory site and the telescope. The Arecibo 305-m telescope is a general-purpose meter-to-centimeter wavelength instrument. Among its many possibilities, are support of the following types of investigation;

Neither planetary radar nor atmospheric physics will be specifically mentioned in this document, (although some information included here may be of use to scientists active in these disciplines). Those requiring more details of the instruments available for such studies are directed to for planetary radar studies, and for atmospheric physics.

General information can be found on the NAIC web site,, including;

Robert Minchin 2017-10-30