4.1 Pre-Observation 3. Initialization L Antenna Setup the preprogramming or the on-site input of parameter 2. Receiver Calibration: Self-Calibration: In general, GPs receivers are 3. Minimum number of satellites to track, considered to be self-calibrating and users do not normally 4. Start and stop time for the session, erform equipment calibration 5. Cutoff elevation angle and Zero-Calibration: One simple test is a zero baseline 6. Assignment of a data file name measurement Modern receivers have several channels and track all satellites I. A preselection is necessary to disregard a satellite. 2. The ephemerides are gathered and stored automatically 3. Many receivers have been designed to require the minimum of operator interaction In the kinematic mode, the phase ambiguities are determined 4.2 Observation during initialization by static or kinematic techniques 1. Communications between survey crews are desirable 1. One static technique is based on the occupation of a and generally increase eff resolution after a few observation epock 2. Most static observations can be performed in an 2. Another method is to perform a(rapid) static survey to automated mode so that an operator is not required determine the vector between the fixed point and the However, data checks during the session, and any unknown starting point for the kinematic survey. regularity should be noted in the field log between the fixed point and the starting point. By this 3. In kinematic surveying applications, after determined to millimeter accuracy for short ilia Doints is antenna swap, the vector between the two nitialization, the roving receiver proceeds to the points for which coordinates are desired. As long as four or The kinematic initialization on-the-fly (oTF) is the most more satellites are continuously tracked by both advanced technique to resolve phase ambiguities(more detail in receivers, vectors from the fixed point can be measure Sect. 9.2). to a high degree of accuracy 4.3 Post-Observation 1. At the completion of a session, a check of the antenna position and re-measurement of its height 2. A final site occupation sheet with the following Information: and station name 5. In Situ Data Processing 3. Start and stop times 5. Name of observer 6. Receiver and antenna serial number 7. Height of antenna and eccentricities in position Problems experienced2 4.1 Pre-Observation 1. Antenna Setup: 2. Receiver Calibration: Self-Calibration: In general, GPS receivers are considered to be self-calibrating and users do not normally perform equipment calibration. Zero-Calibration: One simple test is a zero baseline measurement. 3. Initialization: In static surveying, the initialization of some receivers requires the preprogramming or the on-site input of parameters. 1. Selection of the sampling rate, 2. Bandwidth, 3. Minimum number of satellites to track, 4. Start and stop time for the session, 5. Cutoff elevation angle, and 6. Assignment of a data file name. Modern receivers have several channels and track all satellites 1. A preselection is necessary to disregard a satellite. 2. The ephemerides are gathered and stored automatically. 3. Many receivers have been designed to require the minimum of operator interaction. In the kinematic mode, the phase ambiguities are determined during initialization by static or kinematic techniques. 1. One static technique is based on the occupation of a short, known baseline which allows ambiguity resolution after a few observation epochs. 2. Another method is to perform a (rapid) static survey to determine the vector between the fixed point and the unknown starting point for the kinematic survey. 3. A third static method is to perform an antenna swap between the fixed point and the starting point. By this antenna swap, the vector between the two points is determined to millimeter accuracy for short lines. The kinematic initialization on-the-fly (OTF) is the most advanced technique to resolve phase ambiguities (more detail in Sect. 9.2). 4.2 Observation 1. Communications between survey crews are desirable and generally increase efficiency. 2. Most static observations can be performed in an automated mode so that an operator is not required. However, data checks during the session, and any irregularity should be noted in the field log. 3. In kinematic surveying applications, after initialization, the roving receiver proceeds to the points for which coordinates are desired. As long as four or more satellites are continuously tracked by both receivers, vectors from the fixed point can be measured to a high degree of accuracy. 4.3 Post-Observation 1. At the completion of a session, a check of the antenna position and re-measurement of its height. 2. A final site occupation sheet with the following information: 1. Project and station name 2. Date and session number 3. Start and stop times 4. Station identifier used for file name 5. Name of observer 6. Receiver and antenna serial number 7. Height of antenna and eccentricities in position 8. Meteorological data 9. Problems experienced. 5. In Situ Data Processing