GEOM

Geospatial / Location Data

Information combining location data (where a feature is on Earth) with attribute information (characteristics describing what it is).

Cartographer / Cartography

A practitioner of, and the science/art behind, the creation and design of maps.

Abstraction & Generalization

The practice of simplifying and reducing real-world details to make a map readable and serve its intended purpose.

Map Legend

A reference table on a map defining the shapes, lines, colors, and symbols used to represent features.

General Purpose (Reference) Map

A map showcasing the general geographic location of everyday features (e.g., roads, boundaries, water bodies) without highlighting one over another.

Thematic Map

A map focused heavily on communicating a singular topic, theme, or parameter (e.g., disease spread), often simplifying surrounding features.

Topographic Map

A map focused on illustrating land elevation, terrain shape, hills, valleys, and built environments.

Isoline

A line drawn on a map connecting points of constant, equal value. Examples include isobars (air pressure) and isohyets (rainfall).

Contour Line & Interval

A specific type of isoline connecting points of equal elevation. The Contour Interval is the vertical elevation step between adjacent lines. Closer lines mean a steeper slope.

Spot Height

A single mapped point displaying a surveyed, highly precise location elevation relative to Mean Sea Level (MSL).

Geographic Coordinate System (GCS)

A 3D angular coordinate system modeling the curved Earth. Uses Latitude (parallels measuring North-South from the Equator, \(0^{\circ }\) to \(\pm 90^{\circ }\)) and Longitude (meridians measuring East-West from the Prime Meridian, \(0^{\circ }\) to \(\pm 180^{\circ }\)). Units are in Degrees, Minutes, and Seconds (DMS) or Decimal Degrees (DD).

Earth Shapes & Models

Sphere (basic ball), Ellipsoid (idealized calculus equation accounting for equatorial bulge), and Geoid (lumpy model mapping global gravitational strength variances).

Map Projections

Mathematical conversions of the curved ellipsoid surface onto a flat 2D plane. Always results in a trade-off distortion among Shape (Conformity), Size/Distance, and Direction. Uses basic shapes like Cylinders, Cones, or Azimuthal planes.

Mercator Projection

A classic cylindrical projection wrapped at the Equator. Straight lines retain constant compass bearings (ideal for marine navigation), but it massive distorts size away from the equator (e.g., Greenland looking the size of Africa).

Universal Transverse Mercator (UTM)

A projected coordinate system wrapped sideways (transverse). Divides the globe into 60 UTM Zones (6 degrees longitude wide each). Coordinates are measured linearly in meters using vertical Eastings (measured from a central meridian given a False Origin of 500,000 mE) and horizontal Northings (measured from the Equator at 0 mN).

The Three Norths

True North (direction pointing to the geographic North Pole where longitudes converge), Magnetic North (direction a magnetic compass needles point, drifts over time requiring Declination adjustments), and Grid North (the artificial orientation alignment of a grid system like UTM).

Map Scale Relationships

The ratio of map distance to ground distance. Large-scale maps show a small area with large, highly detailed features (low generalization). Small-scale maps show massive land areas where features look small and highly simplified (high generalization). Represented via Representative Fraction (RF) ratios (e.g., 1:50,000), written Scale Statements (1 cm = 4 km), or Scale Bars.

Horizontal Datums

Frameworks matching coordinate grids to physical landmark markers (Benchmarks). Common types: NAD83 (modern North American standard based on the GRS80 ellipsoid), NAD27 (older system utilizing the Clarke 1866 ellipsoid), and WGS84 (global standard utilized by native GPS receivers).

Vertical Datums

Standards used to establish a baseline surface for measuring elevation. Common types in Canada include CGVD28 (tide-gauge benchmark system) and CGVD2013 (modern system tracking space gravity models and GPS).

GNSS
GPS (Navstar)
GLONASS / Galileo / BeiDou

Global Navigation Satellite System is the umbrella term for tracking satellite constellations providing Position, Navigation, and Timing (PNT). GPS is specifically the US network (Navstar satellites). GLONASS is Russian, Galileo is European (civilian-controlled), and BeiDou is Chinese.

GNSS Architecture

Space: Satellite arrays continuously broadcasting microwave signals carrying Almanac (constellation status) and Ephemeris (precise orbital paths) information.
Ground Control: Base stations checking orbital paths and uploading clock corrections.
User: Standalone hardware units (Recreational, Mapping, or Survey grade) that exclusively receive timing data.

Trilateration

Measuring absolute distances (speed of light \(\times \) travel time signal discrepancies) from 4 or more spheres in space to pinpoint an \(X, Y, Z\) location and account for clock errors. (Triangulation uses angles; Trilateration uses distances).

Atmospheric Interference
Multipath Error
PDOP

Atmospheric: Ionosphere gas electrons and Troposphere moisture disrupting and slowing down signals.
Multipath: Radio waves reflecting off hard surfaces (buildings, tree canopies, water) creating confusing "echo signals."
PDOP: Position Dilution of Precision. Poor mathematical accuracy caused when visible satellites are tightly clustered together in the sky.

DGPS
SBAS (WAAS/EGNOS)
RTK & NRTK
PPP

DGPS (Differential): Using a stationary local Base over a known monument alongside a traveling Rover to cancel out shared errors either via Post-processing or real-time fields.
SBAS: Geostationary satellite correction networks. North America uses WAAS; Europe uses EGNOS; Galileo uses global HAS signals.
RTK: Real-Time Kinematic tracker using carrier-phase wavelengths to grab centimeter-level accuracy instantly.
PPP: Precise Point Positioning. Long occupation times processed later via specialized web networks (e.g., CSRS-PPP).

Waypoints
Tracks / Track Log

Waypoints: Singular, hand-marked field point coordinates (\(X, Y, Z\)).
Tracks: An active automated breadcrumb trail of sequential points logged over time intervals.

GIS Software

Geographic Information Systems. Computer packages designed to tie Spatial data (coordinates showing where) to Attribute data (tables looking like spreadsheets mapping what). Includes legacy ArcGIS Desktop (ArcMap/ArcCatalog), modern ArcGIS Pro, cloud-based ArcGIS Online, and open-source QGIS.

Vector Model

Represents the world discretely through explicit math coordinate points. Features are drawn as isolated Points (\(1\times\) coordinate), Lines (minimum of 2 points), or Polygons (minimum of 3 lines enclosing an area). Highly precise.

Raster Model

Maps continuous landscape variables (elevations, imagery, temperature) across space using a uniform grid of square grid blocks called Pixels / Cells. Detail depends directly on cell size (Resolution). Stretches and looks "blocky" when over-zoomed.

Shapefile

A legacy vector architecture splitting spatial and tabular components into multiple files. Requires matching .shp (geometry), .dbf (attribute table), and .shx (spatial index) files. Limitations: Maximum 2 GB size ceiling, maximum 10-character header limits, and can hold only a single geometry type per file.

Geodatabase (.gdb)

A localized database container grouping multiple geometry layers together seamlessly. Visible layers inside are called Feature Classes, which can be sub-sorted inside Feature Datasets. Looks like an incomprehensible cluster folder inside Windows File Explorer, requiring ArcGIS Pro to read.

Project File (.aprx)

The master command file tracking tool connections, maps, layout settings, and references. ArcGIS Pro does not embed spatial files within the project document directly; it merely logs reference pointers.

Default Geodatabase

An automatically generated database inside your workspace directory that catches scratch outputs created by processing tools.

Project Toolbox (.tbx)

A built-in system file directory designed to archive localized custom formulas, scripts, or automated processing sequences.

Metadata

"Data about the data." Embedded or supplemental logs detailing data creators, production dates, permitted uses, quality lineage, and attribute table data dictionary definitions (explaining cryptic table headers).

Web Map Services (WMS)

Streaming connection protocols linking georeferenced maps over the web. Used mostly as read-only, contextual un-editable backgrounds (Base layers).

Data Licensing Agreements

Legal contracts outlining restrictive bounds on usage, replication, or distribution rights for acquired map datasets.

Open Data

Public framework initiatives by governing bodies making fundamental base layout maps entirely free and unrestricted for the public.

GeoGratis

The federal government's master spatial portal web interface administered through Natural Resources Canada.

Ontario GeoHub

Provincial data center directory run by Geospatial Ontario under the Ministry of Natural Resources (MNR).

SOLRIS

Southern Ontario Land Resource Information System. Remote-sensing land-cover resource utilizing the Ecological Land Classification (ELC) framework.

OWES (Wetlands)

Ontario Wetland Evaluation System. Classifies field-mapped or remote ecosystems into specific groupings (marsh, swamp, fen, bog, open water).

OHN & ORN

Ontario Hydrographic Network (OHN): Tracks lakes (polygons) and watercourses (lines).
Ontario Road Network (ORN): Tracks road centerlines, speed boundaries, and surface types.

Georeferencing

The mechanical process of taking a generic unreferenced raster image (like a scanned map) and registering it into a known coordinate workspace by placing digital anchor pins called Control Points.

Digitizing

Manually creating vector graphics by tracing features using a cursor. Modern methods use Heads-up digitizing, where users place point anchors called Vertices directly on a computer screen.