Developing a process for estimating Doppler frequency from raw data Shannon Rodríguez, Student University of Puerto Rico Mayagüez Campus NASA Goddard Space Flight Center- SIECA Program ABSTRACT Radars are important instruments for studying the Earth system. Meteorological radars have a long heritage for measuring precipitation and have more recently been develo To this end, the Cloud Radar System (CRS), a 94 GHz (3mm wavelength) polarimetric Doppler radar, was developed for cloud studies. The radar is designed to operate on OBJECTIVE: Develop a data acquisition and analysis method that would help in finding the source of bias in velocity estimates of CRS. Cloud Radar System (CRS) 94 GHz Doppler radar GOALS: - Gather raw data from radar. - Develop data analysis process in MATLAB DATA ACQUISITION DOPPLER RADAR Different methods to estimate Doppler frequency: - FFT - Pulse Pair Processing Dual PRF (5KHz-4KHz) 4 MHz RF=94GHz IF=60 MHZ Radar Front End Data Processing Filter ALGORITHM PULSE PAIR ALGORITHM Tdel 1 R(TS ) M Tdel M 1 P *(n) P(n 1) n 1 Im( R (TS )) a tan Re( R (TS )) fd 2 TS RESULTS: Code I Code II FFT THEORY Power Spectrum Power Spectrum ACKNOWLEDGMENTS fc fc+fd fd This work was supported by NASA Goddard Space Flight Center and the SIECA (Summer Institute in Engineering and Computer Applications) Program through UPRM CLiMMATE laboratory. Special thanks to Fernando Pellerano, Paul Racette and Lihua Li.