Interpretation of 6 and 21 cm observations of Jupiter

Observations of Jupiter's radio emission were made at a frequency of 1412 MHz (21cm) in 1977 and at 4885 MHz (6cm) in 1978 using the Westerbork Synthesis Radio telescope in the Netherlands. The thermal disk temperatures at these wavelengths yield values of 320±20 K at 21 cm and 220±8 K at 6 cm. The first value requires an overabundance of ammonia by a factor of three with respect to the solar value, the second one is in agreement with the value expected for a convective model atmosphere with solar abundances for all chemical elements. The data at this wavelength however show no or very little limb darkening on the planet, indicating that there is a layered rather than a uniformly mixed atmosphere. A sudden increase in the ammonia abundance by a factor of about three below the 210–220 K level is proposed to explain this fact and also both derived disk temperatures.     

New information on Saturn and its rings from multi-frequency VLA data

High resolution radio data of Saturn have been obtained at 1.3, 2, 6, and 21 cm, at different inclination angles of the ring plane. Preliminary results of limb darkening curves on the planet and optical depth measurements in the rings are described.     

Establishing satellite data bases in developing countries: A critical view

Remote sensing is a data gathering and analysis technique that offers the possibility of natural resource evaluation. Countries that have not yet evaluated their main resources owing to the lack of basic knoweldge of their territory, are attracted by the idea of rapidly creating data banks through the use of remote sensing. While such a technique offers advantages over traditional means of data acquisition, it requires special systems and methods of analysis that are not particularly easy to assimilate. The building of data bases is taken here as the framework for analyzing some problems confronted by developing countries when trying to incorporate the techniques of teledetection.