1What is geodetic data collection?
The process of gathering precise information about the Earth’s shape, size, gravity field, and positions of points on its surface
2What are the main types of geodetic data?
Positional data, distance & direction data, gravity data, astronomical data, and satellite data
3What is triangulation?
A classical method of geodesy that measures angles in networks of triangles
4What is trilateration?
A classical method of geodesy that measures distances using electronic distance measurement instruments
5What is leveling used for?
To measure height differences between points
6What are astronomical observations used for in geodesy?
To determine latitude, longitude, and azimuth by observing stars and the Sun
7What is GNSS/GPS surveying?
A modern method that uses satellites to determine precise positions
8What is Satellite Laser Ranging (SLR)?
A technique that measures the distance to satellites using laser pulses
9What does VLBI (Very Long Baseline Interferometry) do?
Uses radio telescopes to observe quasars and measure Earth orientation and positions
10What is DORIS?
A satellite geodetic technique that measures satellite positions using ground-based beacons
11What does InSAR (Interferometric Synthetic Aperture Radar) measure?
Ground deformation using radar images from satellites
12What are the steps in geodetic data collection?
Planning, field measurement, data processing, adjustment, and storage/sharing
13What mathematical method is commonly used to adjust geodetic data?
The method of least squares
14What are some applications of geodetic data collection?
Mapping, engineering projects, GPS navigation, tectonic monitoring, and sea-level measurement
15What is Satellite Laser Ranging (SLR)?
A technique that measures the round-trip travel time of short laser pulses sent from ground stations to satellites equipped with retroreflectors
16What does SLR primarily measure?
The precise distance between the ground station and the satellite, with millimeter accuracy
17What are applications of SLR?
Determining Earth’s center of mass, monitoring tectonic plate motion, measuring variations in Earth’s rotation, and tracking satellite orbits
18What is Very Long Baseline Interferometry (VLBI)?
A geodetic technique that uses radio telescopes at great distances apart to observe distant quasars simultaneously
19What does VLBI measure?
The difference in arrival time of radio signals at different telescopes to determine Earth orientation, plate motions, and baseline lengths
20What are applications of VLBI?
Studying Earth’s rotation, nutation, polar motion, and maintaining the International Celestial Reference Frame (ICRF)
21What is Satellite Altimetry?
A technique that measures the height of the satellite above the sea surface using radar pulses
22What does satellite altimetry provide?
Global measurements of sea surface height, ocean circulation, tides, and sea level rise
23What are applications of satellite altimetry?
Oceanography, climate studies, monitoring ice sheets, and improving the geoid model