Share Email Print

Proceedings Paper

Research progress on a focal plane array ladar system using chirped amplitude modulation
Author(s): Barry L. Stann; Ahmed Abou-Auf; Keith Aliberti; John Dammann; Mark Giza; Gerard Dang; Greg Ovrebo; Brian Redman; William Ruff; Deborah Simon
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

The Army Research Laboratory is researching a focal plane array (FPA) ladar architecture that is applicable for smart munitions, reconnaissance, face recognition, robotic navigation, etc.. Here we report on progress and test results attained over the past year related to the construction of a 32x32 pixel FPA ladar laboratory breadboard. The near-term objective of this effort is to evaluate and demonstrate an FPA ladar using chirped amplitude modulation; knowledge gained will then be used to build a field testable version with a larger array format. The ladar architecture achieves ranging based on a frequency modulation/continuous wave technique implemented by directly amplitude modulating a near-IR diode laser transmitter with a radio frequency (rf) subcarrier that is linearly frequency modulated (chirped amplitude modulation). The diode's output is collected and projected to form an illumination field in the downrange image area. The returned signal is focused onto an array of optoelectronic mixing, metal-semiconductor-metal detectors where it is detected and mixed with a delayed replica of the laser modulation signal that modulates the responsivity of each detector. The output of each detector is an intermediate frequency (IF) signal resulting from the mixing process whose frequency is proportional to the target range. This IF signal is continuously sampled over a period of the rf modulation. Following this, a signal processor calculates the discrete fast Fourier transform over the IF waveform in each pixel to establish the ranges and amplitudes of all scatterers.

Paper Details

Date Published: 21 August 2003
PDF: 11 pages
Proc. SPIE 5086, Laser Radar Technology and Applications VIII, (21 August 2003); doi: 10.1117/12.486977
Show Author Affiliations
Barry L. Stann, Army Research Lab. (United States)
Ahmed Abou-Auf, PyramidTech, Inc. (United States)
Keith Aliberti, Army Research Lab. (United States)
John Dammann, Army Research Lab. (United States)
Mark Giza, Army Research Lab. (United States)
Gerard Dang, Army Research Lab. (United States)
Greg Ovrebo, Army Research Lab. (United States)
Brian Redman, Army Research Lab. (United States)
William Ruff, Army Research Lab. (United States)
Deborah Simon, Army Research Lab. (United States)

Published in SPIE Proceedings Vol. 5086:
Laser Radar Technology and Applications VIII
Gary W. Kamerman, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?