Editing Venera (section)

===Venera 15 and 16===
{{Main|Venera 15|Venera 16}}
[[File:VenusTopoVenera.jpg|right|thumb|Radar topography obtained by Venera 15/16]]The 1983 [[Venera 15 and 16]] spacecraft were orbiter missions, similar to previous probes, but the entry probes were replaced with surface imaging radar equipment. Radar imaging was necessary to penetrate the dense cloud of Venus and both missions included identical synthetic aperture radar (SAR) and radio altimeter systems. The SAR system was crucial in the mapping efforts of the mission and featured an 8-month operational tour to capture Venus's surface at a resolution of 1 to 2 kilometers (0.6 to 1.2 miles).<ref>{{Cite web |title=Venera 15 & 16 |url=https://solarviews.com/eng/venera16.htm |access-date=2022-05-14 |website=solarviews.com}}</ref> When the system was switched to radio altimeter mode the antenna operated at an 8-centimeter wavelength band to send and receive signals off of the Venusian surface over a period of 0.67 milliseconds.  

The results were a detailed map of the reflectivity distribution over the surface of the Venusian Northern Hemisphere. The linear distance measurements that were taken ranged from 91 to 182 kilometers. The twin Soviet spacecraft flew in near-polar elliptical orbits and succeeded in mapping the top half of the northern atmosphere (from the north pole to 30 degrees N latitude, about 115&nbsp;million square kilometers or 71&nbsp;million square miles) by the end of the main mission. An altimeter provided topographical data with a height resolution of 50 m (164 feet), and an East German instrument mapped surface temperature variations.<ref>{{Cite web |title=In Depth {{!}} Venera 15 |url=https://solarsystem.nasa.gov/missions/venera-15/in-depth |access-date=2022-05-15 |website=NASA Solar System Exploration |archive-date=7 August 2020 |archive-url=https://web.archive.org/web/20200807110711/https://solarsystem.nasa.gov/missions/venera-15/in-depth/ |url-status=dead }} {{PD notice}}</ref>