Glosarium

Geospatial data is information about physical objects and features on Earth that includes their geographic location, spatial relationships, and associated attributes.

GeoTIFF is a standardized raster image format that embeds geospatial metadata directly into TIFF files, enabling georeferenced imagery and digital elevation models in surveying and mapping applications.

A Geographic Information System (GIS) is a computer-based tool that captures, stores, analyzes, and visualizes spatial data and geographic information for surveying, planning, and decision-making applications.

GLONASS is a Russian satellite navigation system providing global positioning and timing services similar to GPS, widely used in surveying and geospatial applications.

GNSS is a satellite-based navigation system that provides precise positioning, navigation, and timing information to users worldwide through multiple constellations of orbiting satellites.

A specialized antenna that receives signals from Global Navigation Satellite System (GNSS) satellites to enable precise positioning and surveying measurements.

The point within a GNSS antenna where the electromagnetic signals are effectively received, which may differ from the physical center and must be calibrated for accurate positioning.

The measured distance and three-dimensional vector between two GNSS receiver positions, forming the foundation of relative positioning and survey networks.

A GNSS epoch is a specific moment in time at which a Global Navigation Satellite System receiver collects and records positioning measurements from satellites.

Radio frequency bands used by Global Navigation Satellite Systems (GNSS) to transmit positioning signals, with L1 at 1575.42 MHz, L2 at 1227.60 MHz, and L5 at 1176.45 MHz.

Multipath is the degradation of GNSS signal accuracy caused by reflected satellite signals arriving at the receiver antenna after bouncing off nearby surfaces.

GNSS signal processing refers to the computational techniques used to receive, decode, and analyze satellite navigation signals to determine precise position, velocity, and time information.

A satellite-based navigation system that determines precise three-dimensional coordinates (latitude, longitude, and altitude) of survey points anywhere on Earth.

GPS Week is a continuous count of weeks since January 6, 1980, used as the fundamental time reference in the Global Positioning System and critical for synchronizing surveying measurements and GNSS data processing.

Grade control is the surveying process of establishing and monitoring elevation references to ensure construction elements are built to specified vertical heights and slopes.

Ground point filtering is a data processing technique that removes non-ground points from LiDAR or photogrammetric point clouds to isolate terrain elevation data for surveying applications.

The Geodetic Reference System 1980 (GRS80) is a standardized mathematical model of Earth's shape used as the basis for global geodetic datums and coordinate systems in modern surveying and mapping.

Ground Sample Distance (GSD) is the distance on the ground between the center of adjacent pixels in an aerial or satellite image, measured in units such as centimeters or meters.

HDOP is a dimensionless factor that describes the geometric strength of satellite positions and their effect on the accuracy of horizontal positioning in GNSS surveying.

A horizontal angle is the angular measurement between two lines or directions in a horizontal plane, typically measured from a point of observation to establish position and direction in surveying work.

A measurement of the horizontal angle between a reference direction and a target point, obtained by reading the graduated horizontal circle on a surveying instrument.

A hydrographic survey is the systematic measurement and mapping of underwater and coastal water features, including depths, seafloor characteristics, and navigational hazards.

ICP is an algorithm that automatically registers and aligns three-dimensional point clouds by iteratively finding the closest point pairs between datasets to minimize spatial differences.

A computational algorithm that automatically aligns two three-dimensional point clouds by iteratively minimizing the distance between corresponding points.

Industry Foundation Classes (IFC) is an open, neutral data format standard for sharing building information models across multiple disciplines including surveying, architecture, engineering, and construction.

Image overlap is the percentage of common ground area visible in two consecutive photographs or images used in photogrammetry and aerial surveying.

Instrument calibration is the systematic process of comparing and adjusting surveying equipment measurements against known standards to ensure accuracy and reliability in field operations.

A protective container specifically designed to transport, store, and safeguard surveying instruments during field operations and between job sites.

The process of determining the correct integer number of wavelengths in GNSS carrier phase measurements to achieve centimeter-level positioning accuracy.

A surveying method that determines the position of a point by measuring angles from two or more known reference stations to establish precise horizontal or vertical location.

A mathematical technique in GNSS surveying that eliminates ionospheric delays by combining dual-frequency signals to improve positioning accuracy.

The propagation delay of electromagnetic signals passing through the ionosphere, caused by free electrons that reduce signal velocity below the speed of light.

ISO 17123 is an international standard that establishes testing procedures and accuracy requirements for surveying instruments to ensure consistent measurement performance and data quality across projects.

A real-time positioning technique using GNSS receivers in motion to determine precise coordinates by continuously tracking satellite signals and applying corrections.

KML (Keyhole Markup Language) and KMZ (compressed KML) are XML-based file formats used to display geographic data and survey measurements in mapping and geospatial applications.

A conformal map projection that uses a cone tangent or secant to the Earth's surface, minimizing distortion over mid-latitude regions and preserving angles while maintaining relative accuracy for surveying and mapping applications.

A legal survey that establishes property boundaries and ownership limits to create or verify land title documents for real estate transactions.

LAS (Log ASCII Standard) is an open-source file format designed to store and exchange three-dimensional point cloud data acquired from LIDAR scanning systems.

LAS (Log ASCII Standard) is an open-source file format designed to store and exchange 3D point cloud data from LiDAR surveys and other surveying instruments in a standardized, vendor-neutral manner.

A surveying instrument that uses laser light to measure distances between points by calculating the time it takes for light to reflect off a target and return to the device.

LAZ is a lossless compression format for point cloud data that reduces file size while preserving all surveying and spatial information without data loss.

A mathematical method used in surveying to process redundant measurements and minimize errors, producing the most probable values for survey coordinates and observations.

A precise written identification of a parcel of land using standardized surveying methods and references to establish its exact boundaries and location for legal and property ownership purposes.

Leica Cyclone is a comprehensive point cloud processing and visualization software suite developed by Leica Geosystems for analyzing, managing, and converting three-dimensional survey data from laser scanners and other surveying instruments.

Leica Infinity is a comprehensive office software platform designed for processing, analyzing, and managing surveying data collected from Leica instruments and external sources.

Leveling is a surveying technique used to determine elevation differences and establish vertical control by measuring the vertical distance between points using an optical or digital level instrument.

LiDAR is a remote sensing technology that uses laser pulses to measure distances and create detailed three-dimensional maps of terrain and objects.

LiDAR intensity refers to the strength or amplitude of the laser signal reflected back from surveyed surfaces, providing additional information about material properties and surface characteristics beyond distance measurements.

A coordinate system established at a specific project location using arbitrary or project-defined origins and axes rather than national geodetic references.

A longitudinal profile is a two-dimensional graphical representation of ground elevation along a surveyed line or route, showing vertical changes relative to horizontal distance.