1 Introduction to Geographic Information Systems Free Online FlashCards

What is a geographic information system (GIS)?

A computer-based system for collecting, managing, analyzing, and displaying information linked to locations on Earth.

What are spatial data attributes?

Descriptive or measured values associated with a geographic feature, such as a road’s name, number of lanes, or speed limit.

Why might two GIS layers appear misaligned?

They may appear misaligned if their coordinate systems or datums differ and the GIS does not correctly transform between them.

What does GIS metadata record?

Metadata documents details such as a dataset’s source, date, meaning, coordinate system, quality, and limitations.

What is remote sensing?

It collects information about an area from a distance, commonly using sensors on satellites or aircraft that measure reflected or emitted energy.

What does buffering do in spatial analysis?

Buffering creates zones within a specified distance of geographic features, such as areas near bus stops.

How does vector data represent geographic features?

Vector data represent discrete geographic features with coordinates, using points, lines, or polygons.

How does raster data represent an area?

A raster divides an area into grid cells, each storing a value such as elevation, temperature, or land-cover class.

How does raster cell size affect spatial resolution?

Smaller cells can represent finer spatial detail; larger cells summarize broader areas.

What does a map projection do?

It transforms positions on the curved Earth to a flat map. Every projection introduces some distortion.

What does a geodetic datum specify?

A datum specifies the reference used to measure and locate positions.

What does geocoding do, and what limits its precision?

It converts a place description, often a street address, into geographic coordinates; the result may be an approximate position rather than an exact entrance.