Terms used in aerial mapping and geospatial data delivery.
Plain-language definitions for the technical terms that appear throughout this site and in Anchorpoint Geospatial project deliverables.
Drone mapping involves coordinate systems, processing software, file formats, and regulatory terms that aren't always familiar to everyone on a project team. These definitions cover the terms most commonly used in Anchorpoint deliverables, proposals, and capability statements.
A five-character identifier issued by the Defense Logistics Agency (DLA) to suppliers doing business with the U.S. federal government. Required for SAM.gov registration and government contracting. Anchorpoint Geospatial CAGE Code: 1ZV21.
Lines on a map connecting points of equal elevation. Generated from a DSM or DTM. Delivered as vector files (DXF, SHP, GeoJSON) at a specified interval — typically 0.5 ft or 1 ft for construction-grade mapping.
The mathematical framework that ties spatial data to real-world positions on the Earth. A CRS specifies both the horizontal datum (how x/y positions are measured) and the vertical datum (how elevations are measured). Common CRS choices include State Plane, UTM, and WGS84. Anchorpoint delivers data in whichever CRS a project requires.
Earthwork quantities representing how much material was removed (cut) or added (fill) relative to a design grade or base surface. Derived by comparing a current DSM to a baseline surface. Used for pay-application support, earthwork tracking, and bid verification.
A three-dimensional dataset consisting of millions of georeferenced points, each with x, y, z coordinates and optionally color (RGB) values. Generated by photogrammetry software matching overlapping aerial images. Denser than traditional LiDAR survey, delivered as LAS or LAZ files.
A raster elevation model representing the top surface of everything in the scene — buildings, trees, equipment, and ground. Derived from the dense point cloud. Delivered as a GeoTIFF. Used for volumetric analysis, visibility studies, and as-built documentation.
A bare-earth elevation model with above-ground features removed. Created by classifying and filtering the point cloud to retain only ground returns. More accurate for drainage analysis, grading plans, and flood modeling than a DSM.
CAD-native vector file formats. DXF (Drawing Exchange Format) is open; DWG is Autodesk’s native format. Anchorpoint delivers contour lines, breaklines, and TINs in DXF or DWG for direct use in AutoCAD Civil 3D and similar software.
The Federal Aviation Administration regulations governing commercial drone operations in the United States. A Part 107 Remote Pilot Certificate is required for any commercial UAS flight. Anchorpoint Geospatial holds an active Part 107 certificate. Operations requiring airspace authorization (controlled airspace, temporary flight restrictions) are coordinated through FAA LAANC or waiver as applicable.
Physical targets placed on the ground at surveyed locations, used to tie aerial imagery to a known coordinate system during processing. With RTK-equipped drones, GCPs are generally not required for standard mapping accuracy. Check points (CPs) are sometimes used to independently verify accuracy without influencing the model.
The current NGS geoid model used to convert ellipsoidal heights (GPS/GNSS output) to orthometric heights (elevations above mean sea level, i.e., NAVD88). A geoid model is required any time GPS-derived elevations need to match surveyed benchmark elevations. GEOID18 is the version used for the conterminous United States.
A standard raster image format with embedded georeferencing metadata — the coordinate system, spatial extent, and pixel resolution are stored inside the file. Used for orthomosaics, DSMs, and DTMs. Opens natively in ArcGIS, QGIS, AutoCAD, and most other GIS and CAD platforms.
A state-level densification of the National Spatial Reference System, providing more accurate control than the older NAD83 network. Written as NAD83(HARN). The standard horizontal datum for most Washington State survey and mapping work.
Standard binary file formats for point cloud data. LAS is the uncompressed format; LAZ is a losslessly compressed version. Both contain x, y, z coordinates per point along with classification codes (ground, building, vegetation, etc.) and RGB color values when available. Open natively in ArcGIS, QGIS, CloudCompare, and Civil 3D.
The horizontal geodetic datum used as the basis for most U.S. survey and mapping work. Defines the x/y (latitude/longitude or State Plane/UTM) coordinate framework. Realizations include NAD83(HARN) and NAD83(2011), which are more accurate densifications of the original network. Anchorpoint delivers data in NAD83(HARN) / Washington South unless the project specifies otherwise.
A six-digit code used by federal agencies to classify businesses by industry type. Required for federal contracting and SAM.gov registration. Anchorpoint Geospatial primary NAICS: 541370 (Surveying and Mapping Services).
Real-time correction signals from a network of continuously operating reference stations (CORS), used to improve GNSS positioning accuracy without a physical base station on site. Common networks include the NGS CORS network, Washington State Reference Network (WSRN), and commercial RTN providers. Used in conjunction with RTK positioning to achieve centimeter-level accuracy.
A geometrically corrected aerial image mosaic in which distortions from camera tilt and terrain relief have been removed. Each pixel has a precise geographic location. Unlike a raw aerial photo, an orthomosaic can be used for accurate distance, area, and boundary measurements. Delivered as a GeoTIFF.
A periodic billing document submitted by a contractor to an owner requesting payment for work completed to date. Earthwork pay apps typically require quantity documentation — stockpile volumes, cut/fill progress — which drone-derived volumetrics can provide on the same schedule as the billing cycle.
The science of extracting geometric information from photographs. In aerial drone mapping, photogrammetry software (such as Pix4Dmatic) analyzes hundreds of overlapping images to reconstruct a precise 3D model of the site, producing point clouds, meshes, orthomosaics, and surface models.
Professional photogrammetry processing software by Pix4D, optimized for large datasets and RTK-equipped drones. Produces calibrated point clouds, DSMs, DTMs, orthomosaics, and 3D meshes. Anchorpoint uses Pix4Dmatic for all processing and Pix4D Cloud for client-facing delivery.
See Dense Point Cloud.
A satellite positioning technique that provides centimeter-level accuracy in real time by using correction data from a fixed base station or correction network. An RTK receiver on the drone geotags each image with a precisely positioned coordinate, enabling accurate photogrammetry without placing ground control points. Typical horizontal accuracy: 1–3 cm. Typical vertical accuracy: 2–5 cm.
The U.S. federal government’s primary database for vendors seeking to do business with federal agencies. SAM.gov registration is required before a company can receive federal contract awards or grants. Anchorpoint Geospatial SAM.gov registration is in progress.
A federal small-business designation for companies majority-owned and controlled by service-disabled veterans. SDVOSB firms are eligible for set-aside contracting programs across federal agencies. Certification is administered through the SBA VetCert program. Anchorpoint Geospatial SDVOSB certification is pending.
A set of 124 geographic zones covering the United States, each using a map projection that minimizes distortion for a specific region. Coordinates are in feet (US survey feet in most states). Washington State is divided into a North zone and a South zone; Anchorpoint operates primarily in the Washington South zone (EPSG:2286 in US survey feet, EPSG:32149 in meters).
A three-dimensional model in which a geometric surface (mesh) is overlaid with photographic texture mapped from the source imagery. Produces a photorealistic 3D representation of the site. Delivered via the Pix4D Cloud viewer or as an OBJ/FBX file for use in other 3D software.
A vector surface model built from triangles connecting sample points of known elevation. TINs represent terrain more efficiently than rasters in areas with variable complexity. Commonly used in Civil 3D for surface modeling, grading, and volume calculation. Delivered as a LandXML or DXF file.
A 12-character alphanumeric identifier issued by SAM.gov, replacing the older DUNS number as the standard identifier for entities doing business with the federal government. Anchorpoint Geospatial UEI: SF4UBKWUDGM6.
A global coordinate system that divides the Earth into 60 north-south zones, each 6° wide. Coordinates are in meters. Pierce County, WA falls in UTM Zone 10N. UTM is widely used in GIS workflows that span state boundaries or require metric units.
The calculation of material volumes from 3D surface data. In construction, typically used to measure stockpile quantities or cut/fill progress. A current DSM is compared against a base surface (design grade or previous flight) to compute the difference in volume. Results include cut volume, fill volume, and net balance, exportable as a CSV report.
The global datum used by GPS satellites. WGS84 coordinates are what a consumer GPS or phone reports. For high-accuracy mapping, WGS84 is typically converted to a project-specific datum (NAD83, State Plane, UTM) that matches the engineer’s or surveyor’s existing workflow. WGS84 and NAD83 differ by less than 1 meter in North America and are often treated as equivalent for GIS purposes.