6. With A-s activated. in the emitted signal the P-code replaced by the unknown Y-code. Thus, traditional P-code Two main advantages of the p-code receiver: correlation technique can no longer be applied To measure long (100 km) lines with a fet 7. This type of receiver can operate in noderate length lines(20 km) providing carrier phase data and code pse sudoral nges for the L2 frequency without knowledge of the minutes of measured phases of Ll andL, ear tion of the 8. The L2 tracking is accomplished using four techniques 1)Signal squaring 3)Code correlation followed by squaring 4)Z-tracking technique 4. Y-code Receivers 1. This type of receiver provides access to the P-code Summary 2 code ranges and phases derived from LI What have we learnt? L2 signals by the de correlation Which parts are important? 3. The access to the posed by SA. 4. Only users authorized by the doD have access to Assignment 2 1. Detailed description to basic GPS positioning principle 2. What are the SA and A-s technology? 3. Describe the GPS satellite constellation 4. Describe the GPS control segments. 5. List the classification of GPS receivers and riefly describe the 4 types of GPs receivers (characteristics and drawback)7 6. With A-S activated, in the emitted signal the P-code is replaced by the unknown Y-code. Thus, traditional P-code correlation technique can no longer be applied. 7. This type of receiver can operate in codeless mode, providing carrier phase data and code pseudoranges for the L2 frequency without knowledge of the Y-code. 8. The L2 tracking is accomplished using four techniques: 1) Signal squaring 2) Cross correlation 3) Code correlation followed by squaring 4) Z-tracking technique Two main advantages of the P-code receiver: – To measure long (100 km) lines with a few centimeters. P-code instruments can measure moderate length lines (20 km). – Centimeter level with as little as some minutes of data collection based on a linear combination of the measured phases of Ll and L2. 4. Y-code Receivers 1. This type of receiver provides access to the P-code with A-S invoked. 2. The code ranges and phases can be derived from L1 and L2 signals by the P-code correlation technique. 3. The access to the P-code is achieved by installing Auxiliary Output Chips (AOC) in each receiver channel. These chips allow the decryption of the y￾code into the P-code and also correct the degradation imposed by SA. 4. Only users authorized by the DoD have access to the AOC. Summary What have we learnt? Which parts are important? Assignment 2 1. Detailed description to basic GPS positioning principle. 2. What are the SA and A-S technology? 3. Describe the GPS satellite constellation. 4. Describe the GPS control segments. 5. List the classification of GPS receivers, and briefly describe the 4 types of GPS receivers (characteristics and drawback)