Radio occultation of the Venusian atmosphere and bistatic radiolocation of the surface of Venus using the Venera‐9 and Venera‐10 satellites

Abstract

Experimental results for the radio occultation of the Venusian atmosphere using the Venera-9 and Venera-10 satellites are discussed. The time dependences of the field strength and frequency during immersion of the vehicles behind the planet and during their emersion from behind it are given. The dependences of the refraction index, density, pressure, temperature, and electron number density on the altitude above the planeCs surface have been obtained. The results of bistatic radiolocation of the Venus surface with the aid of the Venera-10 satellite are also presented. An analysis is made of the energy spectrum and variations of the Doppler frequency of a radio signal reflected from the planeCs surface. The distribution of the relative heights and of rms slopes of irregularities for two areas of the Venusian surface has been found.

Microwave absorptivity by sulfuric acid in the Venus atmosphere: First results from the Venus Express Radio Science experiment VeRa

“…The varying defocusing loss results from irregularities of the refractive index implying that the observed intensity variations must be attributed to the varying refractive index. Signal intensity variations in radio occultation experiments, known as intensity scintillations were first observed by Mariner 5 (Woo et al, 1974) and by Mariner 10 (Woo, 1975), the Veneras (Kolosov et al, 1979;Gubenko et al, 2001), Pioneer Venus (Woo et al, 1980) and the Magellan spacecraft (Hinson and Jenkins, 1995). Leroy and Ingersoll (1995) showed that those intensity scintillations may be associated with vertically propagating gravity waves.…”

Structure of the Venus neutral atmosphere as observed by the Radio Science experiment VeRa on Venus Express

“…The first radio occultation investigation of Venus was conducted during the flyby of Mariner 5 in 1967 [ Stanford Mariner Group , 1967; Kliore et al , 1967; Fjeldbo et al , 1971]. This was followed by Mariner 10 [ Howard et al , 1974; Nicholson and Muhleman , 1978], Venera‐9 and ‐10 [ Kolosov et al , 1979], Venera‐15 and ‐16 [ Yakovlev et al , 1991], and Magellan [ Jenkins et al , 1994; Steffes et al , 1994; Hinson and Jenkins , 1995]. To date, the most extensive campaign of radio occultation experiments at Venus was carried out with PVO [ Kliore and Patel , 1980, 1982; Kliore , 1985].…”

Radio Occultation Method for Remote Sensing of the Atmosphere and Ionosphere

“…Detailed investigations of the atmosphere and ionosphere of Venus started in 1975 with usage of the first Venus artifical satellites Venera 9 and 10. By means of these spacecrafts, the RO experiments at three frequencies were conducted in 50 regions of Venus [9][10][11][12][13]. During these experiments effects of radio waves propagation through the ionosphere and dense Venusian atmosphere were studied.…”