|
Reverse Geocoding
Reverse geocoding is the process of converting a location as described by geographic coordinates (latitude, longitude) to a human-readable address or place name. It is the opposite of forward geocoding (often referred to as address geocoding or simply "geocoding"), hence the term reverse. Reverse geocoding permits the identification of nearby street addresses, places, and/or areal subdivisions such as neighbourhoods, county, state, or country. Combined with geocoding and routing services, reverse geocoding is a critical component of mobile location-based services and Enhanced 911 to convert a coordinate obtained by GPS to a readable street address which is easier to understand by the end user, but not necessarily with a better accuracy. Reverse geocoding can be carried out systematically by services which process a coordinate similarly to the geocoding process. For example, when a GPS coordinate is entered the street address is interpolated from a range assigned to the road se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Coordinate System
The geographic coordinate system (GCS) is a spherical or ellipsoidal coordinate system for measuring and communicating positions directly on the Earth as latitude and longitude. It is the simplest, oldest and most widely used of the various spatial reference systems that are in use, and forms the basis for most others. Although latitude and longitude form a coordinate tuple like a cartesian coordinate system, the geographic coordinate system is not cartesian because the measurements are angles and are not on a planar surface. A full GCS specification, such as those listed in the EPSG and ISO 19111 standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values for the same location. History The invention of a geographic coordinate system is generally credited to Eratosthenes of Cyrene, who composed his now-lost ''Geography'' at the Library of Alexandria in the 3rd century&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Address Geocoding
Address geocoding, or simply geocoding, is the process of taking a text-based description of a location, such as an address or the name of a place, and returning geographic coordinates, frequently latitude/longitude pair, to identify a location on the Earth's surface. Reverse geocoding, on the other hand, converts geographic coordinates to a description of a location, usually the name of a place or an addressable location. Geocoding relies on a computer representation of address points, the street / road network, together with postal and administrative boundaries. * Geocode (''verb''): provide geographical coordinates corresponding to (a location). * Geocode (''noun''): is a code that represents a geographic entity ( location or object).Sometimes the term can be used in a broader sense: the characterization of a neighborhood, locality, etc., according to such demographic features as ethnic composition or the average income or educational level of its inhabitants, especially a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocoding
Address geocoding, or simply geocoding, is the process of taking a text-based description of a location, such as an address or the name of a place, and returning geographic coordinates, frequently latitude/longitude pair, to identify a location on the Earth's surface. Reverse geocoding, on the other hand, converts geographic coordinates to a description of a location, usually the name of a place or an addressable location. Geocoding relies on a computer representation of address points, the street / road network, together with postal and administrative boundaries. * Geocode (''verb''): provide geographical coordinates corresponding to (a location). * Geocode (''noun''): is a code that represents a geographic entity (location or object).Sometimes the term can be used in a broader sense: the characterization of a neighborhood, locality, etc., according to such demographic features as ethnic composition or the average income or educational level of its inhabitants, especially as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network (PSTN), and computer networks, such as the Internet. In packet switching networks, routing is the higher-level decision making that directs network packets from their source toward their destination through intermediate network nodes by specific packet forwarding mechanisms. Packet forwarding is the transit of network packets from one network interface to another. Intermediate nodes are typically network hardware devices such as routers, gateways, firewalls, or switches. General-purpose computers also forward packets and perform routing, although they have no specially optimized hardware for the task. The routing process usually directs forwarding on the basis of routing tables. Routing tables maintain a record of the routes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Location-based Service
A location-based service (LBS) is a general term denoting software services which use geographic data and information to provide services or information to users. LBS can be used in a variety of contexts, such as health, indoor object search, entertainment, work, personal life, etc. Commonly used examples of location based services include navigation software, social networking services, location-based advertising, and tracking systems. LBS can also include mobile commerce when taking the form of coupons or advertising directed at customers based on their current location. LBS also includes personalized weather services and even location-based games. LBS is critical to many businesses as well as government organizations to drive real insight from data tied to a specific location where activities take place. The spatial patterns that location-related data and services can provide is one of its most powerful and useful aspects where location is a common denominator in all of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhanced 911
Enhanced 911, E-911 or E911 is a system used in North America to automatically provide the caller's location to 911 dispatchers. 911 is the universal emergency telephone number in the region. In the European Union, a similar system exists known as E112 (where 112 is the emergency access number) and known as eCall when called by a vehicle. An incoming 911 call is routed to a Public Safety Answering Point (PSAP), which is a call center operated by the local government. At the PSAP, the call is answered by a specially trained official known as a 9-1-1 dispatcher. The dispatcher's computer receives information from the telephone company about the physical address (for landlines) or geographic coordinates (for wireless) of the caller. This information is used to dispatch police, fire, medical and other services as needed. Call routing Landline routing Calls to 911 over the public switched telephone network (PSTN) are routed to a special router (known as Selective Router, or 9-1-1 Ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georeference
Georeferencing means that the internal coordinate system of a map or aerial photo image can be related to a geographic coordinate system. The relevant coordinate transforms are typically stored within the image file (GeoPDF and GeoTIFF are examples), though there are many possible mechanisms for implementing georeferencing. The most visible effect of georeferencing is that display software can show ground coordinates (such as latitude/ longitude or UTM coordinates) and also measure ground distances and areas. In other words, georeferencing means to associate a digital image file with locations in physical space. The term is commonly used in the geographic information systems field to describe the process of associating a physical map or raster image of a map with spatial locations. Georeferencing may be applied to any kind of object or structure that can be related to a geographical location, such as points of interest, roads, places, bridges, or buildings. Geographic locations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Site
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjacent cells, in a cellular network. The raised structure typically supports antenna and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing (for CDMA2000/ IS-95 or GSM systems), primary and backup electrical power sources, and sheltering. Multiple cellular providers often save money by mounting their antennas on a common shared mast; since separate systems use different frequencies, antennas can be located close together without interfering with each other. Some provider companies operate multiple cellular networks and similarly use colocated base stations for two or more cellular networks, ( CDMA2000 or GSM, for example). Some cities require that cell sites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GeoNames
GeoNames (or GeoNames.org) is a user editable geographical database available and accessible through various web services, under a Creative Commons attribution license. The project was founded in late 2005. The GeoNames dataset differs from, but includes data from, the US Government's similarly named GEOnet Names Server. Database and web services The GeoNames database contains over 25,000,000 geographical names corresponding to over 11,800,000 unique features. All features are categorized into one of nine feature classes and further subcategorized into one of 645 feature codes. Beyond names of places in various languages, data stored include latitude, longitude, elevation, population, administrative subdivision and postal codes. All coordinates use the World Geodetic System 1984 (WGS84). Those data are accessible free of charge through a number of Web services and a daily database export. Wiki interface The core of GeoNames database is provided by official public sourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenStreetMap
OpenStreetMap (OSM) is a free, open geographic database updated and maintained by a community of volunteers via open collaboration. Contributors collect data from surveys, trace from aerial imagery and also import from other freely licensed geodata sources. OpenStreetMap is freely licensed under the Open Database License and as a result commonly used to make electronic maps, inform turn-by-turn navigation, assist in humanitarian aid and data visualisation. OpenStreetMap uses its own topology to store geographical features which can then be exported into other GIS file formats. The OpenStreetMap website itself is an online map, geodata search engine and editor. In 2004, OpenStreetMap was created by Steve Coast in response to the Ordnance Survey, the United Kingdom's national mapping agency, failing to release its data to the public and under free licences. Initially, maps were created only via GPS traces, but it was quickly populated by importing public domain geographi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Engineer
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accomplishes a task with very little (if any) insight into exactly how it does so. It is essentially the process of opening up or dissecting a system to see how it works, in order to duplicate or enhance it. Depending on the system under consideration and the technologies employed, the knowledge gained during reverse engineering can help with repurposing obsolete objects, doing security analysis, or learning how something works. Although the process is specific to the object on which it is being performed, all reverse engineering processes consist of three basic steps: Information extraction, Modeling, and Review. Information extraction refers to the practice of gathering all relevant information for performing the operation. Modeling refers to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
