altimeter measurements
51Measurement of sea ice — Annual growth and retreat of the polar ice packs from SeaWiFS images Measurement of sea ice is important for safety of navigation and for monitoring the environment, particularly the climate. Record keeping of direct observations began over a… …
52Global Positioning System — GPS redirects here. For other uses, see GPS (disambiguation). Geodesy Fundamentals …
53Argo (oceanography) — Argo is an observation system for the Earth s oceans that provides real time data for use in climate, weather, oceanographic and fisheries research. [ [http://www.aip.org/pt/vol 53/iss 7/p50.html Physics Today: Argo Begins Systematic Global… …
54Compass — This article is about the direction finding instrument used in navigation. For other uses, see Compass (disambiguation). A simple dry magnetic pocket compass …
55Barometer — Schematic drawing of a simple mercury barometer with vertical mercury column and reservoir at base …
56Ocean surface wave — Ocean surface waves are surface waves that occur on the free surface of the ocean. They usually result from wind, and are also referred to as wind waves. Some waves can travel thousands of miles before reaching land. They range in size from small …
57Secondary surveillance radar — SSR antenna of Deutsche Flugsicherung at Neubrandenburg, in Mecklenburg/Western Pomerania Secondary surveillance radar (SSR)[1] is a radar system used in air traffic control (ATC), that not only detects an …
58Metrication in Australia — took place between 1970 and 1988. Before then, Australia mostly used the imperial system for measurement, which the Australian colonies had inherited from the United Kingdom. Between 1970 and 1988, imperial units were withdrawn from general legal …
59Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
60Surface weather observation — Surface weather observations are the fundamental data used for safety as well as climatological reasons to forecast weather and issue warnings worldwide. [Office of the Federal Coordinator of Meteorology. [http://www.ofcm.gov/fmh 1/pdf/B CH2.pdf… …
