Geospatial and Drone Common Terms
Airbourne LiDAR
In airborne LiDAR, a laser scanner is mounted on an aircraft or helicopter, which scans the ground surface below it with laser beams. The reflected signals are then collected by the scanner and processed to generate 3D point clouds of the terrain.
Attribute Table
A tabular file containing rows and columns. In a GIS, attribute tables are associated with a class of geographic features, such as wells or roads. Each row represents a geographic feature. Each column represents one attribute of a feature, with the same column representing the same attribute in each row.
BIM
Building Information Modeling (BIM): These days, a growing number of architects, engineers, and contractors are using BIM. BIM is an intelligent model-based process that connects these professionals so they can more efficiently design, build, and operate buildings and infrastructure through information modeling.
BVLOS
Beyond Visual Line of Sight (BVLOS) refers to drone operations where the visual observer responsible for keeping an eye on the drone can’t physically see it during the flight.
Different types of BVLOS are :
Drones flying long distances
Drones flying at very high altitude
Drones flying in confined spaces
Drones flying in an area with large obstructions.
Band
One layer of a multispectral image representing data values for a specific range of the electromagnetic spectrum of reflected light or heat (e.g., ultraviolet, blue, green, red, near- infrared, infrared, thermal, radar, etc.). Also, other user-specified values derived by manipulation of original image bands. A standard color display of a multispectral image shows three bands, one each for red, green and blue. Satellite imagery such as LANDSAT TM and SPOT provide multispectral images of the Earth, some containing seven or more bands.
Boolean Expression
A type of expression that reduces to a true or false (logical) condition. A Boolean expression contains logical expressions (e.g., DEPTH > 100) and Boolean operators. A Boolean operator is a keyword that specifies how to combine simple logical expressions into complex expressions. Boolean operators negate a predicate (NOT), specify a combination of predicates (AND), or specify a list of alternative predicates (OR). For example, DEPTH > 100 AND DIAMETER > 20
CLU
Common land unit. A vector outline of tracts and/or fields. Many CLU polygons make up a coverage. The definition adopted for use in USDA service centers is: “The smallest unit which has a permanent, contiguous boundary, common management or treatment, common owner, or common client association." An example of a CLU might be a CRP field, a fenced pasture, or a strip in a crop/fallow ratio
CSSM
The Content Standards for Spatial Metadata. A document produced by the Federal Geographic Data Committee (FGDC) that describes spatial metadata.
Cartesian Coordinate System
A two-dimensional, planar coordinate system in which x measures horizontal distance and y measures vertical distance. Each point on the plane is defined by an x,y coordinate. Relative measures of distance, area, and direction are constant throughout the Cartesian coordinate plane.
Central Meridian
A zone constant used when defining a map projection.
Column
The vertical dimension of a table. A column has a name and a data type applied to all values in the column.
Compression
A software tool used to reduce the size of large raster files. Compression can be lossless, which preserves image quality, or lossy, which sacrifices some image quality for the sake of greatly reduced file size. Examples include MrSID and JPEG2000.
Constellation
1. A specific set of satellites used in calculating positions; 3 satellites for 2D fixes, 4 satellites or more for 3D fixes.
2. All of the satellites visible to a GPS receiver at one time. The optimum constellation is the constellation with the lowest PDOP.
Contour
A line connecting points of equal surface value.
Contour Interval
The difference in surface values between contours.
Coordinate
An x,y location in a Cartesian coordinate system or an x,y,z coordinate in a three dimensional system. Coordinates represent locations on the Earth’s surface relative to other locations.
Coordinate System
A reference system used to measure horizontal and vertical distances on a planimetric map. A coordinate system is usually defined by a map projection, a spheroid of reference, a datum, one or more standard parallels, a central meridian, and possible shifts in the x- and y-directions to locate x,y positions of point, line, and area features. A common coordinate system is used to spatially register geographic data for the same area.
DGM
Digital Geospatial Metadata. DGM was approved in June 1994 by the Federal Geographic Data Committee (FGDC). DGM describes the specifications for the content, quality, condition, and other characteristics of metadata (data about data). The standard provides a common set of terminology and definitions for the documentation of geospatial data. DGM establishes the names of data elements and groups of data elements to be used for these purposes, definitions of these data elements and groups, and information about the values that are to be provided for the data elements
DLG
1. Digital line graph files from the U.S. Geological Survey (USGS), including data from the base map categories such as transportation, hydrography, contours, and public land survey boundaries.
2. The digital format standards published by USGS for exchanging cartographic data files and in which the USGS delivers digital line graph data sets.
DOQ
Digital orthophoto quadrangle. Digital representation of an aerial photograph or other remotely sensed data that have been rectified to produce an accurate image of the earth by removing tilt and relief displacements which occurred when the photo was taken. Standard USGS format is one quarter of a 7.5' quad. Data is provided at the 1:12000 scale. The DOQ combines the image characteristics of a photograph with the accuracy and scale associated with a map. Typical base layer required for GIS functionality.
Data Dictionary
1. (GIS) A catalog of all data held in a database, or a list of items giving data names and structures. Also referred to as DDID for data dictionary/directory.
2. (GPS) A description of the features and attributes relevant to a particular project or job. This description includes feature names, data type classifications (point, line, area), attribute names, attribute types and attribute values. After being created, a data dictionary can be used to control the capture of features and attributes.
EOS
Earth Observation Satellite. An effort to study the earth as a system while tracking long-term changes on a global scale. EOS, a mission of the National Aeronautics and Space Administration (NASA), will produce petabytes (1,000 terabytes) of satellite image data and also large-scale data sets (terabytes [1,000 gigabytes] a day) to be manipulated and analyzed.
FIPS
The Federal Information Processing Standards. FlPS deals with a wide range of computer system components including the components of most GISs: hardware, storage media, data files, codes, interfaces, data transmission, networking, data management, documentation, programming languages, software engineering, performance, security, and so forth. FlPS 173 is the precursor to the SDTS (Spatial Data Transfer Standard), which includes standardized definitions for a variety of digital mapping terms and addresses federal requirements for accuracy. FlPS provides a U. S. government standard state and country identification code; standards approved for use by U.S. government agencies. FlPS 152-2 includes POSIX.lcompliance.
Geodatabase
An object-based GIS data model developed by ESRI for ArcGIS that stores each feature as rows in a table. Personal geodatabases store data in a Microsoft Access .mdb file. Corporate geodatabases store data in a DBMS such as SQLserver or Oracle. This data structure supports rules-based topology and allows the user to assign behavior to data.
Geodetic Datum
A mathematical model designed to fit part or all of the geoid (the physical earth's surface). Defined by the relationship between an ellipsoid and a point on the topographic surface established as the orgin of a datum. World geodetic datums are typically defined by the size and shape of the ellipsoid and the location of the center of the ellipsoid with respect to the center of the earth.
Image
A graphic representation or description of a scene, typically produced by an optical or electronic device. Common examples include remotely sensed data (e.g., satellite data), scanned data, and photographs. An image is stored as a raster data set of binary or integer values that represent the intensity of reflected light, heat, or other range of values on the electromagnetic spectrum.
LiDAR
LiDAR ( Light Detection and Ranging) is a method used for determining distances by targeting an object or area with a laser and measuring the time for the reflected light to return to the receiver. The data colllected is called point data and can also be used to make digital 3-D models of areas on the surface or ocean.
Pipeline Mapping
Pipeline mapping is the process of creating a detailed map of pipelines and related infrastructure used for the transportation of liquids, gases, or other materials. This technique is commonly used by the oil and gas industry, as well as other industries that rely on pipelines for transportation.
Raster
A raster is a digital image representation that uses a grid of pixels to represent an image.