Geodesy - Topics

How satellite altimetry measures the height of the ocean to the centimetre Why the same coordinates land in different places on WGS84 and NAD83 Why the mapped width of an earthquake zone is far wider than the fault that causes it How a meridian is marked and resurveyed on the ground with geodetic monuments Why longitude counts to 180 twice instead of running from 0 to 360 How accurate is a phone GPS fix in a canyon of glass towers Changing a map datum can shift every coordinate by hundreds of metres UTM zones vs latitudes and longitudes: why surveyors work in metres instead of degrees How to keep a latitude column from turning into dates and scientific notation in a spreadsheet Why a country's land area changes depending on who measured it Why three satellites are not enough to fix your position on the ground How does a GNSS receiver work out your position from satellites that only broadcast time? How is area computed on a curved Earth without distorting the total How many decimal places in a coordinate actually matter before the extra digits are noise Decimal degrees vs degrees minutes seconds: which format surveyors and hikers each prefer A degree of longitude shrinks toward the poles while a degree of latitude stays the same Magnetic declination: the gap between the meridian a compass points to and the true one Zero degrees longitude is fixed by satellites today rather than by a brass strip at Greenwich The point farthest from any ocean sits in Eurasia and has two rival coordinates Mean sea level is not level: how a national height system gets defined How satellites measure Hawaii drifting towards Japan a few centimetres a year UTC vs GMT: what the two labels actually disagree about What a gravity anomaly tells a geodesist about the rock underneath How surveyors measure a mountain's height to the nearest centimetre How ancient Greeks measured Earth's circumference with shadows and simple geometry Why your phone's altitude disagrees with the elevation printed on the map What the geoid is and why the ocean surface is not a perfect sphere How do you fix the elevation of a point nobody has ever surveyed? Meridians are halves of great circles: why due north is the shortest line to the pole Why the Earth bulges at the equator and how that shifts satellite orbits How do you set a survey benchmark that stays trustworthy for a century? Why GNSS receivers only listen and never transmit anything back