Study questions and exercises

Write the answers to the questions in a word document and send it to christian.stranne[at]geo.su.se. Your document should be named with your name and the moment according to the following convention: firstname_lastname_MomentX.docx
Once we received your answers you will get a correction sheet. Correct your own answers using the sheet and where you have questions, please write them in an email to the course email. When you have answered all questions you will also get a code to open the lecture(s) of the next Moment.
The study questions and exercises are only for your own learning and the code system is intended to help you following the course structure and to set your study pace. It is your own responsibility to follow this scheme.

Study questions and exercises on Moment 2

  1. Explain the basic principle behind using electromagnetic waves (radio waves) transmitted from fixed stations with known positions for navigation.
  2. Can a ship’s radar be used to determine the ship’s position? If so, how?
  3. Mention two navigational systems based on electromagnetic waves that were widely used before the modern GNSS systems took over.
  4. What is the main factor that limits the range of navigational systems using electromagnetic waves?
  5. Assume a spherical Earth with a radius of 6370 km and no obstructions, how far can we expect that radio waves reach if the transmitter is mounted at the top of a 50 m high tower?
  6. Why is an extremely accurate and precise clock essential for the common GNSS like GPS, GLONASS and Galileo?
  7. Mention three known sources of errors for a GNSS position along with estimates of how large they are.
  8. What is meant by that a GPS receiver is capable of handling the L1 and L2 bands?
  9. What is a rough estimate of the accuracy of an un-augmented GPS position?
  10. What is a GPS position on Earth referenced to by default?
  11. How come that a so-called Real Time Kinematic (RTK) GPS is able to achieve horizontal and vertical accuracies of 2–3 cm and 4–6 cm respectively?
  12. What is the main difference between a Differential GPS (DGPS) correction provided following IALA recommendations and SBAS?