Spectral analysis of Floating Car Data

[摘要] Floating Car Data (FCD) are one important datasource in traffic telematic systems. The original variable inthese systems is the vehicle velocity. The paper analyses themeasured value “vehicle velocity" by methods of informationtechnology. Consequences for processing, transmissionand storage of FCD under condition of limited resources arediscussed.

Starting point of the investigation is the analysis of spectralcharacteristics of velocity-time-profiles. The spectra aredetermined by the Discrete Fourier Transform (DFT) frommeasurement data and simulation data of a microscopic trafficmodel. One essential property of velocity-time-profiles istheir low-pass characteristic. The resulting cut-off-frequencyis comparatively small and depends on the traffic scenario.Conclusions concerning the necessary sample rate in FCDsystems and the processing of raw data are discussed. Finallythe transinformation of velocity-time-profiles is analysed.This results in similar values for an optimal samplerate of FCD systems under condition of limited transmissioncapacity.

[学科分类] 电子、光学、磁材料