Geographical Coordinate Converter

Longitude is measured East or West from the Prime Meridian (0° longitude), which passes through Greenwich, London. Latitude is measured North or South from the Equator (0° latitude). The maximum latitude is 90° N (North Pole) or 90° S (South Pole), and the maximum longitude is 180° E or 180° W (which meet at the International Date Line).

The Global Positioning System (GPS) relies on a network of at least 24 satellites orbiting Earth. A GPS receiver calculates its position by precisely timing signals sent from these satellites and using trilateration.

The shortest distance between two points on the surface of a sphere (like Earth) is along a great-circle path. Lines of longitude are great circles, and the Equator is the only line of latitude that is a great circle.

A geodetic datum (like WGS 84) is a reference model of the Earth. Since the Earth is not a perfect sphere, different datums exist to provide better fits for different regions. Using the wrong datum can lead to location errors of hundreds of meters.

While determining latitude at sea was relatively easy using celestial navigation, accurately determining longitude was a major scientific challenge for centuries. The problem was finally solved in the 18th century with the invention of the marine chronometer by John Harrison.

A compass points to the Magnetic North Pole, not the Geographic North Pole. The angle of difference between these two points at any given location is called magnetic declination, and it's crucial for accurate navigation with a compass.

The Universal Transverse Mercator (UTM) system is another common way to represent coordinates. Instead of latitude/longitude, it uses a grid system measured in meters, which simplifies distance and area calculations over smaller regions.

Geocaching is a popular outdoor recreational activity where participants use a GPS receiver or mobile device to hide and seek containers, called 'geocaches' or 'caches', at specific geographic coordinates.

The antipode of any place on Earth is the point on the Earth's surface which is diametrically opposite to it. For example, the antipode of a point in northern Spain is in New Zealand. Calculating antipodes requires precise coordinate manipulation.

The International Date Line, located around 180° longitude, is where the date changes by one day. It zig-zags to avoid dividing countries or island groups into two different days.

Geohashing is a recreational activity inspired by the webcomic xkcd. It uses a stock market value and the current date to generate a new set of random coordinates each day for people to meet up at.

One minute of latitude is approximately one nautical mile (1.852 km). This relationship is why nautical miles are so convenient for marine and air navigation.

The Earth is not a perfect sphere; it's an oblate spheroid, slightly flattened at the poles and bulging at the equator. This affects high-precision distance calculations and is accounted for in modern geodetic systems like WGS 84.

The geoid is the shape that the ocean surface would take under the influence of the Earth's gravity and rotation alone, in the absence of other influences such as winds and tides. It's a more accurate representation of Earth's mean sea level than a simple ellipsoid.

What3Words is a proprietary geocoding system that has divided the world into 3-meter squares and assigned each one a unique three-word address. It's an alternative, more human-friendly way to communicate precise locations.

ISO 6709 is the international standard for the representation of geographic point location by coordinates. It provides a standardized format for exchanging latitude, longitude, and altitude data.

The Earth's magnetic poles are not fixed. The North Magnetic Pole is currently drifting from the Canadian Arctic towards Siberia at a rate of several tens of kilometers per year, requiring updates to navigation models.

Before electronic navigation, sailors used instruments like the sextant and astrolabe to measure the angle of celestial bodies (like the Sun or North Star) above the horizon to determine their latitude.