GPS for Land surveyors, Third Edition
2.The clocks in GPS satellites are rubidium and sesium oscillators, whereas quartz crystal oscillators provide the frequency standard in most GPS receivers. Concerning the relationship between these standards, which of the following statements is not true?
(a) Quartz clocks are not as stable as the atomic standards in the GPS satellites and are more sensitive to temperature changes, shock, and vibration.
(b) Both GPS receivers and satellites rely on their oscillators to provide a stable reference so that other frequencies of the system can be generated from or compared with them.
(c) The foundation of the oscillators in GPS receivers and satellites is the piezoelectric effect .
(d) The oscillators in the GPS satellites are also known as aromic clocks.
3. what is an advantage available using a dual frequency GPS receiver that is not available using a single frequency GPS receiver?
(a) A single frequency GPS receiver cannot collect enough data to perform single, double, or triple difference solutions.
(b) A dual-frequency receiver affords an opportunity to track the P code, but a single frequency receiver cannot.
(c) A dual frequency receiver has access to the Navigation code, but a single frequency receiver does not.
(d) Over long baselines, a dual-frequency receiver has the facility of modeling and virtually removing the ionospheric bias whereas a single frequency receiver cannot.
4. Which of the following satements is not correct concerning refraction of the GPS signal in the troposphere?
(a) L1 and L2 carrier waves are refracted equally.
(b) When a GPS satellite is near the horizon, its signal is most affected by the atmosphere
(c) THe density of the troposphere governs the severity of its effect on a GPS signal.
(d) The wet component of refraction in the troposphere contributes the larger portion of the range error.
5. In a between-receivers single difference across a short baseline, which of the following problems are not virtually eliminated?
(a) satellite chock errors
(b) atmospheric bias
(c) integer cycle ambiguities
(d) orbital errors