Mie lidar observations of lower tropospheric aerosols and clouds

Veerabuthiran, S.; Razdan, A. K.; Jindal, Mukesh Kumar; Dubey, Deepak Kumar; Sharma, Ramesh C.

doi:10.1016/j.saa.2011.08.021

Cited by 8 publications

(4 citation statements)

References 14 publications

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“…The ranges of the VMD parameters to be optimized are set and the WOA model is initialized, including the number of search agents and the maximum iteration number. Here, K takes an integer in the interval (2,15), α is assigned in the interval (1000-10,000), the number of search agents is 30, and the maximum number of iterations is 15.…”

Section: Experiments With Simulated Signalsmentioning

confidence: 99%

“…Lidar is a combination of traditional radar technology and modern laser technology and has the advantages of high resolution, wide detection range, and strong anti-interference ability [1]. Its applications in atmospheric remote sensing detection, e.g., aerosol, cloud layer, and visibility, have become increasingly important [2,3]. However, the power of the lidar echo signal decays with the exponential attenuation of the aerosol extinction coefficient and the square of the distance between the lidar and the target according to the lidar equation, and the signal can be easily interfered with by noise from electric fluctuations and stray lights [4].…”

Section: Introductionmentioning

confidence: 99%

“…where p(k) = E k /E is the percentage of the energy of the kth mode in the total signal energy, 2 , and…”

mentioning

confidence: 99%

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Efficient Lidar Signal Denoising Algorithm Using Variational Mode Decomposition Combined with a Whale Optimization Algorithm

Chang

et al. 2019

Remote Sensing

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Although lidar is a powerful active remote sensing technology, lidar echo signals are easily contaminated by noise, particularly in strong background light, which severely affects the retrieval accuracy and the effective detection range of the lidar system. In this study, a coupled variational mode decomposition (VMD) and whale optimization algorithm (WOA) for noise reduction in lidar signals is proposed and demonstrated completely. The combination of optimal VMD parameters of decomposition mode number K and quadratic penalty α was obtained by using the WOA and was critical in acquiring satisfactory analysis results for VMD denoising technology. Then, the Bhattacharyya distance was applied to identify the relevant modes, which were reconstructed to achieve noise filtering. Simulation results show that the performance of the proposed VMD-WOA method is superior to that of wavelet transform, empirical mode decomposition, and its variations. Experimentally, this method was successfully used to filter a lidar echo signal. The signal-to-noise ratio of the denoised signal was increased to 23.92 dB, and the detection range was extended from 6 to 10 km.

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Section: Experiments With Simulated Signalsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Efficient Lidar Signal Denoising Algorithm Using Variational Mode Decomposition Combined with a Whale Optimization Algorithm

Chang

et al. 2019

Remote Sensing

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“…APDs also have a range of applications in LIght Detection And Ranging (LIDAR), and optical communications [19,20]. Likewise, there are plans to use APDs on astrophysical satellites such as Astro-H [21] and ATHENA/IXO [22], since APDs are much more compact than traditional photomultipliers (PMTs), and operate at a relatively low bias voltage and with low power consumption.…”

Section: Introductionmentioning

confidence: 99%

Expected radiation damage of reverse-type APDs for the Astro-H mission

et al. 2012

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Scheduled for launch in 2014, Astro-H is the sixth Japanese X-ray astronomy satellite mission. More than 60 silicon avalanche photodiodes (Si-APDs; hereafter APDs) will be used to read out BGO scintillators, which are implemented to generate a veto signal to reduce background contamination for the hard X-ray imager (HXI) and a soft gamma-ray detector (SGD). To date, however, APDs have rarely been used in space experiments. Moreover, strict environmental tests are necessary to guarantee APD performance for missions expected to extend beyond five years. The radiation hardness of APDs, as for most semiconductors, is particularly crucial, since radiation in the space environment is severe. In this paper, we present the results of radiation tests conducted on reverse-type APDs (provided by Hamamatsu Photonics) irradiated by gamma rays ( 60 Co) and 150 MeV protons. We show that, even under the same 100 Gy dose, high energy protons can cause displacement (bulk) damage in the depletion region and possibly change the activation energy, whereas gamma-ray irradiation is less prone to cause damage, because ionization damage dominates only the surface region. We also present quantitative guidance on how to estimate APD noise deterioration over a range of temperatures and radiation doses. As a practical example, we discuss the expected degradation of the BGO energy threshold for the generation of veto signals, following several years of Astro-H operation in Low Earth Orbit (LEO), and directly compare it to experimental results obtained using a small BGO crystal.

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Validation and Spatiotemporal Distribution of GEOS-5–Based Planetary Boundary Layer Height and Relative Humidity in China

Chen

et al. 2018

Adv. Atmos. Sci.

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Mie lidar observations of lower tropospheric aerosols and clouds

Cited by 8 publications

References 14 publications

Efficient Lidar Signal Denoising Algorithm Using Variational Mode Decomposition Combined with a Whale Optimization Algorithm

Efficient Lidar Signal Denoising Algorithm Using Variational Mode Decomposition Combined with a Whale Optimization Algorithm

Expected radiation damage of reverse-type APDs for the Astro-H mission

Validation and Spatiotemporal Distribution of GEOS-5–Based Planetary Boundary Layer Height and Relative Humidity in China

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