Related Experiment Video
Updated: Sep 22, 2025
09:57
Multiplex Chemical Imaging Based on Broadband Stimulated Raman Scattering Microscopy
Published on: July 25, 2022
4.1K
Pulse Broadening Effects on Ranging Performance of a Laser Altimeter with Return-to-Zero Pseudorandom Noise Code
Hyung-Chul Lim1, Jong Uk Park1, Mansoo Choi1
1Korea Astronomy and Space Science Institute, Daejeon 34055, Korea.
Sensors (Basel, Switzerland)
|May 20, 2022
Summary
Pulse broadening in laser altimeters degrades ranging performance. This study models the effect on return-to-zero pseudorandom noise (RZPN) laser altimeters, providing analytical expressions for performance metrics.
Area of Science:
- Optical engineering
- Remote sensing
- Signal processing
Background:
- Laser altimeters using code modulation can experience pulse broadening when scanning rough or sloped surfaces.
- This pulse broadening degrades ranging performance, affecting signal-to-noise ratio (SNR) and detection probability.
Purpose of the Study:
- To investigate the pulse broadening effect on the ranging performance of return-to-zero pseudorandom noise (RZPN) laser altimeters.
- To derive mathematical models and closed-form expressions for performance analysis.
Main Methods:
- Developed mathematical models to analyze pulse broadening in RZPN laser altimeters.
- Utilized a new flat-topped multi-Gaussian beam (FMGB) model to derive analytical waveforms, approximating impulse response as Gaussian.
- Derived closed-form expressions for peak cross-correlation, SNR, and detection probability.
Main Results:
- The pulse broadening effect was shown to reduce peak cross-correlation.
- Ranging performance was demonstrated to deteriorate due to pulse broadening.
- Analytical expressions were validated using a 3D model of asteroid Itokawa and numerical simulations.
Conclusions:
- The derived analytical expressions are crucial for designing and analyzing RZPN laser altimeters.
- Understanding and quantifying pulse broadening is essential for optimizing laser altimeter performance in challenging terrains.
Keywords:
cross-correlationflat-topped multi-Gaussian beamlaser altimeterpseudorandom noise codepulse broadening effectMore Related Videos
Related Concept Videos
00:59Propagation of Uncertainty from Random Error
1.1K
An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on...
1.1K
01:05Doppler Effect - II
3.6K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
3.6K
01:10Propagation of Uncertainty from Systematic Error
912
The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this...
912
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
1.2K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
1.2K
00:56Doppler Effect - I
3.8K
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
3.8K
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
301
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance.
301