The Motorola PowerStrike GPS Receiver By Patrick Svatek May 8, 2001 The University of Texas at Austin, Dept. of ASE/EM

Motorola PowerStrike Receiver Overview Why the PowerStrike? What IS the PowerStrike? About the PowerStrike Receiver WinOncore Software Receiver Testing –Single Receiver –Dual PowerStrike Receivers –Simulator Data Testing Findings, Conclusions, Remarks

Motorola PowerStrike Receiver Goals for this Project To understand the PowerStrike receiver To understand the WinOncore Software Characterization of the Receiver Creation of a website not just to meet the class requirements, but for the Oncore World to use as a reference Gain expertise on CSR’s new receiver and pass this knowledge on

Motorola PowerStrike Receiver Why the PowerStrike? Motorola Product Donated Hardware to CSR Development potential Interesting to see engineering development product before market Something new and unexplored

Motorola PowerStrike Receiver What IS the PowerStrike? 12-Channel L1 C/A Only Used in terrestrial applications –Vehicle Navigation / Moving Map –OnStar and similar services –Vehicle Theft Locator (motorcycles too) –Shipping Tracking Serial Interface, DGPS capable (receive only)

Motorola PowerStrike Receiver PowerStrike Kit Receiver is actually a combination of components, including RF Module, downconverter, oscillator, correlator, and processor.

Motorola PowerStrike Receiver Other Kit Components Active Antenna (preamp internal) Power Serial Software

Motorola PowerStrike Receiver WinOncore GUI Software Gives exclusive access to the receiver. Can be used to “start” the receiver in order to use other vendor software Software is standalone and configurable Datalogging Graphical

Motorola PowerStrike Receiver Various Features

Motorola PowerStrike Receiver Receiver Testing Single Receiver –18-hour data 15 sec intervals –Show accuracy of measurements Dual Receiver (simultaneous) –Completely separate hardware, same location –Accuracy and Robustness of hardware Simulated with Single Receiver specs –Use start time of single test, use average LLH as reference LLH for sim run –Show pseudo-precision of measurements

Motorola PowerStrike Receiver Single Receiver Logged NMEA GPS Time, LLH Parse data file, post-process for: –MAX, MIN, AVG, STDEV

Motorola PowerStrike Receiver Single Receiver LAT Results Variation Of Approx ft Or 3.53 m

Motorola PowerStrike Receiver Single Receiver LON Results Variation Of Approx. 8.0 ft Or 2.47 m

Motorola PowerStrike Receiver Single Receiver ALT Results Variation Of Approx ft Or 7.5 m

Motorola PowerStrike Receiver Dual Receiver Data collected simultaneously with single receiver experiment Separate hardware Receiver 2Receiver 1

Motorola PowerStrike Receiver Second Receiver LAT Results

Motorola PowerStrike Receiver Second Receiver LON Results

Motorola PowerStrike Receiver Second Receiver ALT Results

Motorola PowerStrike Receiver Comparison of Both Receivers

Motorola PowerStrike Receiver Simulated Position LLH from AVG 2-Hour Simulation from Start Time

Motorola PowerStrike Receiver 1.Latitude absolute average difference of sec (1.27 ft) 2.Latitude absolute variation difference of sec (5.50 ft) 3.Longitude absolute average difference of sec (5.71 ft) 4.Longitude absolute variation difference of sec (8.09 ft) 5.Altitude absolute average difference of 3.12 ft (.95 m) 6.Altitude absolute variation difference of 18.4 ft (5.62 m) Post-Analysis and LLH 2 XYZ gives: Simulated Position Results NOTE: Diff. Almanac, No Tropo & Iono, No Multipath

Motorola PowerStrike Receiver Conclusions & Remarks PowerStrike is a well-designed receiver operating at the limits of the GPS system Not designed for Space Applications, but never tested in space either Testing shows PowerStrike is susceptible to noise from operation near TVs and AC outlets WinOncore Software is an excellent interface tool Software has some bugs Pseudorange not available during testing No easy way to extract data to convert to RINEX for advanced processing and file-sharing

Motorola PowerStrike Receiver