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Analysis Of Ladar Range Resolution Enhancement By Sinusoidal Phase Modulation, Leonard T. Masters, Martin B. Mark, Bradley D. Duncan
Analysis Of Ladar Range Resolution Enhancement By Sinusoidal Phase Modulation, Leonard T. Masters, Martin B. Mark, Bradley D. Duncan
Electro-Optics and Photonics Faculty Publications
The ability of a ladar system to resolve two or more separate returns from a combined echo is related to the effective correlation bandwidth of the pulse emitted by the ladar system. Phase modulation of an outgoing pulse introduces additional frequency components, which increases the effective correlation bandwidth of the pulse and thus improves the range resolution of the system. In this paper, we discuss the general theoretical basis for achieving improved range resolution using a modulated waveform and a matched filter receiver. We then demonstrate these concepts by considering the particular case of improved range resolution for a sinusoidally …
Integrating Reconstructed Scatterometer And Advanced Very High Resolution Radiometer Data For Tropical Forest Inventory, David G. Long, Perry J. Hardin
Integrating Reconstructed Scatterometer And Advanced Very High Resolution Radiometer Data For Tropical Forest Inventory, David G. Long, Perry J. Hardin
Faculty Publications
A scientific effort is currently underway to assess tropical forest degradation and its potential impact on Earth's climate. Because of the large continental regions involved, Advanced Very High Resolution Radiometer (AVHRR) imagery and its derivative vegetation index products with resolutions between 1 and 12 km are typically used to inventory the Earth's equatorial vegetation. Archival AVHRR imagery is also used to obtain a temporal baseline of historical forest extent. Recently however, 50-km Seasat-A Scatterometer (SASS) Ku-band imagery (acquired in 1978) has been reconstructed to = 4-km resolution, making it a supplement to AVHRR imagery for historical vegetation assessment. In order …
Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan
Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan
Electro-Optics and Photonics Faculty Publications
A theoretical performance analysis of a heterodyne ladar system incorporating a single-mode fiber receiver has been performed. For our purposes, the performance parameters of interest are the coupling and mixing efficiency of the ladar receiver, as they relate to the overall system carrier-to-noise ratio. For a receiver incorporating a single-mode fiber mixer, the received and local-oscillator fields are matched both spatially and temporally at the detector, yielding 100% mixing efficiency. We have therefore focused our efforts on determining an expression for the efficiency with which a diffuse return from a purely speckle target can be coupled into the receiving leg …