Estimation of the differential pulse propagation times in two-color laser ranging systems

Kwaifong E. Im, C. S. Gardner

Research output: Contribution to journalArticlepeer-review


Two-color laser ranging systems can be used to determine the atmospheric delay by measuring the difference in propagation times between two optical pulses transmitted at two different wavelengths. In this paper, the performance of a cross-correlation technique for estimating the differential propagation time is analyzed by considering both speckle and shot noise. For the flat diffuse targets, the differential timing accuracy is highly dependent on the receiver bandwidth and the characteristics of the time-resolved speckle. At low signal levels, when the receiver bandwidth is chosen properly, the performance of the correlation estimator is comparable with that of the maximum-likelihood estimator. At high signal levels, however, speckle places a fundamental limit on the performance of the correlation estimator. For the cube-corner reflector arrays, timing performance is dominated by partially developed speckle. The differential propagation time cannot by resolved to better than the pulse widths of the received signals.

Original languageEnglish (US)
Pages (from-to)143-156
Number of pages14
JournalJournal of the Optical Society of America A: Optics and Image Science, and Vision
Issue number1
StatePublished - Jan 1 1986

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Computer Vision and Pattern Recognition


Dive into the research topics of 'Estimation of the differential pulse propagation times in two-color laser ranging systems'. Together they form a unique fingerprint.

Cite this