Location technology — Guides
Coordinates, GPS, geocoding and maps explained in plain language.
Location technology
What Is Latitude and Longitude?Latitude and longitude are two angles that pinpoint any place on Earth. Learn what each one measures, how they are written and how they work together.Positive and Negative Coordinates ExplainedWhy some latitude and longitude values are negative: how the sign maps to north, south, east and west, and how to convert between signs and letters.Latitude First or Longitude First? Coordinate OrderWhich comes first in a coordinate pair? Learn why latitude-longitude and longitude-latitude both exist, and how to spot swapped values.Decimal Degrees vs Degrees Minutes SecondsCompare decimal degrees (DD) with degrees, minutes and seconds (DMS): how each is written, where each is used and which one to choose.How to Convert DMS to Decimal DegreesA step-by-step method to convert degrees, minutes and seconds into decimal degrees and back again, with worked examples and sign rules.How to Find the Coordinates of a PlacePractical ways to get the latitude and longitude of any location: from a map, a phone, a photo or a code, plus tips for checking the result.How Long Is a Degree of Latitude and Longitude?One degree of latitude is about 111 km everywhere, but a degree of longitude shrinks toward the poles. See why and how to estimate distances.Decimal Places in Coordinates: What Precision MeansHow many decimal places of latitude and longitude do you need? See what each digit means in metres, from 111 km down to centimetres.How GPS Works: A Plain-Language ExplanationGPS works by timing radio signals from satellites. Learn how a receiver uses them to work out position, with no internet required.What Is GNSS? GPS, Galileo, GLONASS and BeiDouGNSS is the general term for satellite navigation systems. Learn how GPS, Galileo, GLONASS and BeiDou relate and why phones use several.GPS Accuracy vs Precision: What Is the Difference?Accuracy is how close a location is to the truth; precision is how consistent or finely written it is. Learn the difference for GPS and maps.Why Is My Phone GPS Inaccurate?Common reasons a phone shows the wrong location: blocked sky, reflections, indoor use, weak assistance data and drift, plus ways to improve it.Urban Canyons: Why GPS Fails Among Tall BuildingsIn dense city streets, tall buildings block and reflect satellite signals. Learn what an urban canyon is, how multipath causes errors and what helps.Why GPS Does Not Work Well IndoorsSatellite signals are faint and walls absorb or scatter them. Learn why GPS struggles inside buildings and what phones use instead.How Phones Locate You With Wi-Fi and Cell TowersPhones can estimate position without GPS by matching nearby Wi-Fi networks and cell towers to a database. See how it works and how accurate it is.GPS Altitude and Elevation: Why Height Is Less AccurateWhy GPS height readings are less accurate than horizontal position, and how ellipsoid height differs from elevation above sea level.What Is Geocoding? Turning Addresses Into CoordinatesGeocoding converts a written address or place name into latitude and longitude. Learn how it works, why results vary and where it falls short.What Is Reverse Geocoding?Reverse geocoding turns latitude and longitude into a nearby address or place name. Learn how it works and what its results really mean.Reverse-Geocoded Address vs Real AddressWhy an address returned for coordinates may not match the building's official address, and how to treat it as an approximation.What Is a Map Projection and Why Do Maps Distort?A map projection flattens the curved Earth onto a plane, and every method distorts something. Learn the main types and the trade-offs.What Is Web Mercator? The Projection Behind Web MapsWeb Mercator is the map projection used by most online maps. Learn why it was adopted, what it distorts and when not to use it for measurement.What Is WGS 84? The Datum Behind GPSWGS 84 is the global reference model of the Earth used by GPS and most digital maps. Learn what a datum is and why it matters for coordinates.Coordinate Reference Systems ExplainedA coordinate reference system defines what a set of coordinates actually means. Learn about geographic vs projected systems, datums and EPSG codes.How Map Tiles Work in Web Maps and AppsWeb maps are made of small square tiles loaded as you pan and zoom. Learn how tiles are organised, raster vs vector and why they make maps fast.Map Zoom Levels Explained for Web MapsWhat zoom levels 0 to 20 mean on a web map, how each step halves the scale, and roughly how many metres one pixel covers at each level.UTM Grid System ExplainedUTM divides the world into 60 zones and gives positions in metres as eastings and northings. Learn how zones, bands and coordinates work.MGRS: The Military Grid Reference SystemMGRS is a grid notation built on UTM that names squares with letters and digits. Learn how to read one and how precision is set by digits.What Is a Geohash and How Does It Work?A geohash encodes a latitude and longitude as a short string of letters and digits, where longer strings mean smaller areas. Learn how it works.What Are Plus Codes (Open Location Code)?Plus Codes, or Open Location Code, are short codes built from latitude and longitude. Learn how they are structured and where they are useful.Word-Based Location Systems ExplainedSome systems name locations with a few words instead of numbers. Learn how they work, what they offer and the trade-offs compared with coordinates.How Location Codes Are Generated From CoordinatesA general explanation of how a latitude and longitude become a short code: gridding the Earth, numbering cells and encoding the number.Why a 3 Metre Grid Cell Is PracticalWhy a 3 m by 3 m cell suits addresses and delivery: small enough to tell entrances apart, large enough for real-world GPS and map selection.What Is a Bounding Box in Mapping?A bounding box is the smallest rectangle that contains a place or set of points, defined by four coordinates. Learn how it is used and its limits.What Is Geofencing and How Does It Work?A geofence is a virtual boundary around a real place that triggers actions when a device enters or leaves. Learn how it works and where it is used.Location Privacy and Consent ExplainedWhy location data is sensitive, what informed consent looks like, and practical steps for people and businesses to handle location responsibly.