GIS Geospatial Data Acquisition 2

Question 1

Which satellite constellation is the European equivalent of GPS, providing global navigation services?

Accepted Answer

Galileo

Answer

Galileo is the European Union's global navigation satellite system, providing high-accuracy positioning services independent of GPS.

Question 2

In LiDAR data acquisition, what does 'point density' refer to?

Accepted Answer

The number of points per unit area on the ground

Answer

Point density in LiDAR refers to the number of measured points per square meter or square foot on the ground surface.

Question 3

What is 'dead reckoning' in the context of GPS navigation?

Accepted Answer

Estimating position using known speed, direction, and elapsed time when GPS signal is lost

Answer

Dead reckoning estimates current position by using a previously known position and advancing it using speed, heading, and time when GPS signals are unavailable.

Question 4

What type of remote sensing uses radar pulses to detect surface elevation and penetrate vegetation?

Accepted Answer

Synthetic Aperture Radar (SAR)

Answer

SAR uses microwave radar pulses that can penetrate cloud cover and vegetation canopy, making it useful for mapping terrain beneath forest cover.

Question 5

What is the primary purpose of ground control points (GCPs) in aerial photogrammetry?

Accepted Answer

To georeference and improve the accuracy of aerial imagery

Answer

GCPs are surveyed points on the ground with known coordinates used to georeference aerial photos and correct positional errors in photogrammetric products.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS Geospatial Data Acquisition 2