Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection.
A nautical chart or hydrographic chart is a graphic representation of a sea region or water body and adjacent coasts or banks. Depending on the scale of the chart, it may show depths of water (bathymetry) and heights of land (topography), natural features of the seabed, details of the coastline, navigational hazards, locations of natural and human-made aids to navigation, information on tides and currents, local details of the Earth's magnetic field, and human-made structures such as harbours, buildings, and bridges. Nautical charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. Nautical charting may take the form of charts printed on paper or computerized electronic navigational charts. Recent technologies have made available paper charts which are printed "on demand" with cartographic data that has been downloaded to the commercial printing company as recently as the night before printing. With each daily download, critical data such as Local Notices to Mariners are added to the on-demand chart files so that these charts are up to date at the time of printing.
Piloting or pilotage is the process of navigating on water or in the air using fixed points of reference on the sea or on land, usually with reference to a nautical chart or aeronautical chart to obtain a fix of the position of the vessel or aircraft with respect to a desired course or location. Horizontal fixes of position from known reference points may be obtained by sight or by radar. Vertical position may be obtained by depth sounder to determine depth of the water body below a vessel or by altimeter to determine an aircraft's altitude, from which its distance above the ground can be deduced. Piloting a vessel is usually practiced close to shore or on inland waterways. Pilotage of an aircraft is practiced under visual meteorological conditions for flight.
A bathymetric chart is a type of isarithmic map that depicts the submerged topography and physiographic features of ocean and sea bottoms. Their primary purpose is to provide detailed depth contours of ocean topography as well as provide the size, shape and distribution of underwater features. Topographic maps display elevation above ground and are complementary to bathymetric charts. Charts use a series of lines and points at equal intervals to showcase depth or elevation. A closed shape with increasingly smaller shapes inside of it can indicate an ocean trench or a seamount, or underwater mountain, depending on whether the depths increase or decrease going inward.
Google Maps is a web mapping platform and consumer application offered by Google. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bike, air and public transportation. As of 2020, Google Maps was being used by over one billion people every month around the world.
GRIB is a concise data format commonly used in meteorology to store historical and forecast weather data. It is standardized by the World Meteorological Organization's Commission for Basic Systems, known under number GRIB FM 92-IX, described in WMO Manual on Codes No.306. Currently there are three versions of GRIB. Version 0 was used to a limited extent by projects such as TOGA, and is no longer in operational use. The first edition is used operationally worldwide by most meteorological centers, for Numerical Weather Prediction output (NWP). A newer generation has been introduced, known as GRIB second edition, and data is slowly changing over to this format. Some of the second-generation GRIB are used for derived product distributed in Eumetcast of Meteosat Second Generation. Another example is the NAM model.
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.
Global Navigation Satellite System (GNSS) receivers, using the GPS, GLONASS, Galileo or BeiDou system, are used in many applications. The first systems were developed in the 20th century, mainly to help military personnel find their way, but location awareness soon found many civilian applications.
A satellite navigation device is a user equipment that uses one or more of several global navigation satellite systems (GNSS) to calculate the device's geographical position and provide navigational advice. Depending on the software used, the satnav device may display the position on a map, as geographic coordinates, or may offer routing directions.
Here Technologies is an American–Dutch multinational group dealing with mapping, location data and related automotive services to individuals and companies. It is majority-owned by a consortium of German automotive companies and American semiconductor company Intel whilst other companies also own minority stakes. Its roots date back to U.S.-based Navteq in 1985, which was acquired by Finland-based Nokia in 2007. Here is currently based in The Netherlands.
Google Maps Navigation is a mobile application developed by Google for the Android and iOS operating systems that was later integrated into the Google Maps mobile app. The application uses an Internet connection to a GPS navigation system to provide turn-by-turn voice-guided instructions on how to arrive at a given destination. The application requires connection to Internet data and normally uses a GPS satellite connection to determine its location. A user can enter a destination into the application, which will plot a path to it. The app displays the user's progress along the route and issues instructions for each turn.
Sygic is a Slovak company of global automotive navigation systems for mobile phones and tablets. The company was founded in 2004 and is headquartered in Bratislava, Slovakia. It became the first company to offer navigation for iPhone and second for Android. In 2015 Sygic reached milestone of 100 million downloads of its navigation app.
Turn-by-turn navigation is a feature of some satellite navigation devices where directions for a selected route are continually presented to the user in the form of spoken or visual instructions. The system keeps the user up-to-date about the best route to the destination, and is often updated according to changing factors such as traffic and road conditions. Turn-by-turn systems typically use an electronic voice to inform the user whether to turn left or right, the street name, and the distance to the next turn.
OsmAnd is a map and navigation app for Android and iOS. It uses the OpenStreetMap (OSM) map database for its primary displays, but is an independent app not endorsed by the OpenStreetMap Foundation. It is available in both free and paid versions; the latter unlocks the download limit for offline maps and provides access to Wikipedia points of interest (POIs) and their descriptions from within the app. Map data can be stored on the device for offline use. Using the device's GPS capabilities, OsmAnd offers routing, with visual and voice guidance, for car, bike, and pedestrian. All of the main functionalities work both online and offline.
A moving map display is a type of navigation system output that, instead of numerically displaying the current geographical coordinates determined by the navigation unit or an heading and distance indication of a certain waypoint, displays the unit's current location at the center of a map. As the unit moves around and new coordinates are therefore determined, the map moves to keep its position at the center of the display.
This article contains a list with gratis satellite navigation software for a range of devices. Some of the free software mentioned here does not have detailed maps or the ability to follow streets or type in street names. However, in many cases, it is also that which makes the program free, avoid the need of an Internet connection, and make it very lightweight. Very basic programs like this may not be suitable for road navigation in cars, but serve their purpose for navigation while walking or trekking, and for use at sea. To determine the GPS coordinates of a destination, one can use sites such as GPScoordinates.eu and GPS visualizer.
Here WeGo is a web mapping and navigation service, operated by HERE Technologies and originally developed by Nokia. In 2013, HERE Technologies released this web mapping application for Windows Phone and the World Wide Web as a revamped version of Nokia Maps. HERE Technologies released the HERE Maps application to the Android platform on December 10, 2014, and later for iOS on March 11, 2015. The company changed the product name to HERE WeGo in July 2016. It is the default maps service provider for the Amazon Fire tablets and smartphones.
Locus Map is a multi-functional Android navigation app adding advanced online and offline GPS capabilities to Android devices. Primarily it is designed and used for leisure time outdoor activities like hiking, biking, geocaching. Besides its leisure time utilization the app is also used by professionals e.g. for collecting geospatial data, by rescue squad teams, aerial reconnaissance teams etc.
JOSM(Java OpenStreetMap editor) is a free software desktop editing tool for OpenStreetMap geodata created in Java, originally developed by Immanuel Scholz and currently maintained by Dirk Stöcker. The editing tool contains advanced features that are not present in OSM's default online editor, iD.
Yandex Maps is a Russian web mapping service developed by Yandex. The service provides detailed maps of the whole world, it provides directions and estimated times of arrival for driving, walking, cycling, kick scooter, and public transportation navigation. It includes a search, information about traffic jams, routing and street panoramas. The service was launched in 2004.
