Automatic Pulse Shaping with the AN/FPN-42 and AN/FPN-44A Loran-C transmitters
Abstract
Automatic pulse shape control is simulated for the N/FPN-42 and AN/FPN-44A tube type transmitters. A linear, time invariant (LTI) pole-zero model is developed for each transmitter at a typical operating point using the least squares modified Yule-Walker method and Shank's method. LTI models for a range of operating points are catenated to represent observed nonlinear behavior, and observed time variations are added. After these combined models are tested, a linear controller based on the method of steepest descent is implemented. These models, the control algorithm and transmitter system details such as power supply droop, dual rating and noise are then incorporated into a MATLAB simulation program. In a variety of realistic tests the control algorithm successfully shaped the Loran-C pulse, except that zero-crossing times were not always in tolerance and the algorithm showed a sensitivity to noise. The algorithm controlled Envelope-to-Cycle Difference, produced an entire Phase Code Interval of pulses while compensating for droop and phase code bounce, and produced a near- optimal transmitter drive waveform for the transmitter/antenna system using the dummy load.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1992
- Accession Number
- ADA257860
Entities
People
- Dean C. Bruckner
Organizations
- Naval Postgraduate School