1. A Standard Approach When processing the data based on double-differences by least quare adjustment, the ambiguities are estimated as real or floating point numbers. The first double-difference solution is called the float 3. Search Techniques mbiauitv solution The output is the best estimate of the tation coordinates as well as double- difference ambiguities Shore baseline(e.g, 5km), and long observation span(I hr), the float ambiguities close to integers. ity resolution in this case is merely used to refine the 2. Ambiguity Resolution On-the-Fly AROF OTF, OTRI The OTF techniques have common features like Code ranges are used to define the search space for the g, the determination of an initial solution. A nematic case. A relative code range position is used as the summary of the main features is given in Table 9.5 best estimate of antenna location, and the associated standard viations are used to define the size of the search space (a Please see the Table 9.5, p. 228. To reduce the number of integer ambiguity combinations, the code solution should be as accurate as possible which means Narrow correlator-type code ranges They have a resolution at 10 cm range and improved multipath reduction compared with standard C/A-code receivers 3. Ambiguity Function Method 4. Least Squares Ambiguity Search The basic principle by Counselman and Gourevitch is Technique =p()+N-Aa()4-ip()=N-5an L. The ry group consists of four satellites, which should have a good PDOP, the possible ambiguity sets are 231()=3a()_12N1-12sb(o 2. The remaining secondary satellites are used to eliminate candidates of the possible ambiguity sets cosα+is for the position e linearization of the observation equation) which may be obtaned real ax e range solution. Search Area: The search area may be established by surrounding the 2()-Pka(1)_-2aa() approximate position by a 38 region.5 3. Search Techniques 1. A Standard Approach When processing the data based on double-differences by least squares adjustment, the ambiguities are estimated as real or floating point numbers. The first double-difference solution is called the float ambiguity solution. The output is the best estimate of the station coordinates as well as double-difference ambiguities. Shore baseline (e.g., 5km), and long observation span (1 hr), the float ambiguities close to integers. Ambiguity resolution in this case is merely used to refine the achievable positioning accuracy. For example: 2. Ambiguity Resolution On-the-Fly (AROF, OTF, OTR) Code ranges are used to define the search space for the kinematic case. A relative code range position is used as the best estimate of antenna location, and the associated standard deviations are used to define the size of the search space (a cube, a cylinder, or an ellipsoid). To reduce the number of integer ambiguity combinations, the code solution should be as accurate as possible which means that receiver selection becomes important. • Low noise, • Narrow correlator-type code ranges They have a resolution at 10 cm range and improved multipath reduction compared with standard C/A-code receivers. The OTF techniques have common features like, e.g., the determination of an initial solution. A summary of the main features is given in Table 9.5 p. 228. Please see the Table 9.5, p. 228. 3. Ambiguity Function Method ρ ( ) N δ ( ) 1 AB j j AB t f t AB AB j Φ = + − λ ρ ( ) N δ ( ) 1 AB j j AB t f t AB AB j Φ − = − λ {2 πN ( ) 2ππf ( ) ρ ( )} λ 2π {2 πΦ ( ) AB j AB i t t i t t j AB j AB e e − − = 2 πN 2 πfδ ( )} ρ ( )} λ 2π {2 πΦ ( ) j AB j AB i t i i t t e e e j AB j AB − − = cos α sin α iα e = + i 2 πfδ ( ) ρ ( )} λ 2π {2 πΦ ( ) AB j AB i t i t t e e j AB − − = For one epoch and one satellite The basic principle by Counselman and Gourevitch is 4. Least Squares Ambiguity Search Technique Basic principles: is the separation of the satellites into a primary and a secondary group. 1. The primary group consists of four satellites, which should have a good PDOP, the possible ambiguity sets are determined. 2. The remaining secondary satellites are used to eliminate candidates of the possible ambiguity sets. Approximation: This technique requires an approximation for the position (due to the linearization of the observation equation) which may be obtained from a code range solution. Search Area: The search area may be established by surrounding the approximate position by a 3δ region