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מערכות נווט והנחייה סמסטר אביב – תשע"א טכניון – מכון טכנולוגי לישראל הפקולטה להנדסת אוירונאוטיקה וחלל 13–10–2013 בחן אמצע – מועד א . דקות90 זמן המבחן1. A car is driving on a circular road of radius 1/ km centered at the latitude = 32o, longitude = 35o at a velocity of 25 m/sec. The car drives with constant roll and pitch angle of 0 deg. Assume the car has a navigation system which is ideal except for a scale-factor error of 1000 ppm on the Z-gyro (the gyro with sensitivity axis in the vertical direction) . a. (20 points) Estimate the angular errors as a function of time. b. (20 points) Estimate the velocity errors as a function of time. 2. (40 points) A static (i.e., not moving) GPS receiver is placed at a known location and tracks four GPS satellites. The Ephemeris of three of the satellites are known, but those of the fourth are not and hence the position and velocity of the fourth satellite with respect to time is unknown. Explain how the receiver can compute the position and velocity of the fourth satellite using pseudo-range and pseudo-range-rate measurements. 3. (20 points) Compute the velocity and position errors for an aircraft flying East at 200 m/sec, if the IMU used for the computations has no errors, but the initial orientation is known up to a small roll angle error of 1 mRad.