Geology 495/695: Environmental Geodesy

Extra Credits

Lectures 1-3

Problem 1: Define geodesy as a science and describe concisely the three pillars of modern geodesy.

Problem 2: What is a geodetic "reference system" and what a "reference frame"?

Problem 3: What are the two fundamental global geodetic reference systems and what physical quantity links these two systems together? What are the two conventional systems accepted by IAG and IAU, and what are the corresponding most accurate reference frames? What organization maintains the systems and frames, and where are the conventions published?

Problem 4: For the International Terrestrial Reference Frame (ITRF):

1. How is the ITRF given and published?
2. How do reference coordinates for ITRF reference points change over time?
3. What is the general mathematical relationship between two versions of the ITRF?
4. How can the coordinates of a point in the two systems be compared?

Problem 5: What are the mathematical shapes of the solid Earth that are related to the main phases in the development of geodesy since its beginning and what are the main parameters of these shapes that were the focus of research/observations in these phases?

Problem 6: How is the geodetic reference ellipsoid for the Earth defined and what are the key parameters?

Problem 7: What are the main endogenic and exogenic processes impacting the shape of the Earth from periods of sub-seconds to millions of years?

Please submit the responses by February 28, 2011 (preferably by e-mail to hpplag@unr.edu).

Lectures 4-5

Problem 1: What are key physical constants related to gravitation and the gravity field of a planet and how well are these known?

Problem 2: Name and characterize the main equations related to the gravity potential.

Problem 3: How large are the deviations of the geoid from the reference ellipsoid and how are these deviations explained?

Problem 4: Explain in simple words the origin of tides.

Problem 5: Why do we see ocean tides?

Problem 6: Why are the amplitude and phases of semidiurnal and diurnal tides varying irregularly in space?

Problem 7: How large is the largest equilibrium tide on Earth?

Problem 8: Why does the Moon keep the same face toward the Earth?

Problem 9: How large is the tidal bulge of the Moon?

Problem 10: What are the main rotational eigenmodes of the Earth and to which parts of the Earth are they mainly attributed?

Please submit the responses by March 14, 2011 (preferably by e-mail to hpplag@unr.edu).

Lectures 6-8

Problem 1: Describe the main characteristics of point-geodetic observations versus imaging techniques in terms of spatial and temporal resolution and coverage.

Problem 2: What is the "station motion model" and how does it enter into the analysis of point-geodetic techniques?

Problem 3: Which space-geodetic techniques provide the origin of the reference frame with respect to the center of mass and which provide the scale? Why?

Problem 4: Explain the principle of GNSS reflectometry.

Problem 5: Why are laser retroreflectors on satellites like Global Navigation Satellites, altimeter satellites, and other satellites that use geometrical principles important?

Problem 6: Explain briefly the principle of InSAR and identify the major limitations for accuracy and and applicability. How could these challenges be addressed?

Problem 7: What are the main characteristic of in situ, airborne and spaceborne gravity measurements in terms of temporal and spatial resolution, as well as accuracy as function of spatial and temporal scale?

Problem 8: Explain the principle of GRACE and its main limitations in terms of accuracy.

Please submit the responses by April 18, 2011 (preferably by e-mail to hpplag@unr.edu).