Optical Backscattering Measured by Airborne Lidar and Underwater Glider

Churnside, James H.; Marchbanks, Richard D.; Lembke, Chad; Beckler, Jordon S.

doi:10.3390/rs9040379

Cited by 26 publications

(18 citation statements)

References 51 publications

(81 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some previous studies on LiDAR at 532 nm reports χ (180 • ) was about 1.43 [35], while others report χ (180 • ) = 0.5 [33,34,36]. A new instrument for phase scattering function measurements is required, since most of the current methods cannot be extended to 180 • [37].…”

Section: Discussionmentioning

confidence: 99%

Ocean Optical Profiling in South China Sea Using Airborne LiDAR

Chen

Pan

2019

Remote Sensing

View full text Add to dashboard Cite

Increasingly, LiDAR has more and more applications. However, so far, there are no relevant publications on using airborne LiDAR for ocean optical profiling in the South China Sea (SCS). The applicability of airborne LiDAR for optical profiling in the SCS will be presented. A total of four airborne LiDAR flight experiments were conducted over autumn 2017 and spring 2018 in the SCS. A hybrid retrieval method will be presented here, which incorporates a Klett method to obtain LiDAR attenuation coefficient and a perturbation retrieval method for a volume scattering function at 180 • . The correlation coefficient between the LiDAR-derived results and the traditional measurements was 0.7. The mean absolute relative error (MAE) and the normalized root mean square deviation (NRMSD) between the two are both between 10% and 12%. Subsequently, the vertical structure of the LiDAR-retrieved attenuation and backscattering along airborne LiDAR flight tracks was mapped. In addition to this, ocean subsurface phytoplankton layers were detected between 10 to 20 m depths along the flight track in Sanya Bay. Primary results demonstrated that our airborne LiDAR has an independent ability to survey and characterize ocean optical structure.

show abstract

Section: Discussionmentioning

confidence: 99%

Ocean Optical Profiling in South China Sea Using Airborne LiDAR

Chen

Pan

2019

Remote Sensing

View full text Add to dashboard Cite

show abstract

“…When the type of particles in the water does not change with depth, the Fernald method is better [16,17]. When changes in the depth profile of the optical properties are not too extreme, it is better to utilize the perturbation method [18][19][20]. For HSRL, the 2 properties can be retrieved independently [6,21].…”

Section: Methodsmentioning

confidence: 99%

Detection of Chlorophyll a and CDOM Absorption Coefficient with a Dual-Wavelength Oceanic Lidar: Wavelength Optimization Method

et al. 2020

View full text Add to dashboard Cite

To overcome the retrieval problems in complex water, dual working wavelengths are required instead of a single wavelength in oceanic lidar. The wavelength optimization method of detecting chlorophyll a and Colored Dissolved Organic Matter (CDOM) absorption coefficient with a dual-wavelength lidar is studied in this paper. The inversion methods of chlorophyll a and CDOM absorption are developed based on the water absorption characteristics, which then lead to the inversion error equations. The effects of the wavelength on the inversion errors are studied. For the case in which λ1 and λ2 are both random, the errors are relatively small when λ1 is chosen between 420 and 560 nm and λ2 is selected under 420 nm. For the case in which λ1 is fixed at 532 nm, the errors generally decrease with decreasing λ2, with minimums around 300 and 356–360 nm under different water conditions. The wavelength optimization method discussed in this paper and the penetration depth criterion will be beneficial to the design of the dual-wavelength lidar.

show abstract

“…In recent years, shipborne or airborne LiDAR has a wide range of oceanic applications, including bathymetry [2], measuring the optical properties of the water column [3][4][5], also for detecting plankton scattering layers [6][7][8], bubbles [9], internal waves [10], schools of fish [11] and so on. Recent breakthroughs have now demonstrated that plankton properties can be measured with a satellite LiDAR.…”

Section: Introductionmentioning

confidence: 99%

“…The max relative error percentage at both stations is within 8.3%, and their MREP is within 0.08%. The mean Lidar constant is K = 2.1026 × 10 10 (SR • m3 /s) for our Lidar system. The RMSE of lidar constant at S1 and S2 are 0.043 × 10 10 (SR • m 3 /s) and 0.033 × 10 10 (SR • m 3 /s), respectively.…”

mentioning

confidence: 97%

A Feasible Calibration Method for Type 1 Open Ocean Water LiDAR Data Based on Bio-Optical Models

et al. 2019

View full text Add to dashboard Cite

Accurate calibration of oceanic LiDAR signals is essential for the accurate retrieval of ocean optical properties. Nowadays, there are many methods for aerosol LiDAR calibration, but fewer attempts have been made to implement specific calibration methods for oceanic LiDAR. Oceanic LiDAR often has higher vertical resolution, needs greater signal dynamic range, detects several orders of magnitude lower less depth of penetration, and suffers from the effects of the air-sea interface. Therefore the calibration methods for aerosol LiDAR may not be useful for oceanic LiDAR. In this paper, we present a new simple and feasible approach for oceanic LiDAR calibration via comparison of LiDAR backscatter against calculated scatter based on iteratively bio-optical models in clear, open ocean, Type 1 water. Compared with current aerosol LiDAR calibration methods, it particularly considers geometric losses and attenuation occurring in the atmosphere-sea interface. The mean relative error percentage (MREP) of LiDAR calibration constant at two different stations was all within 0.08%. The MREP between LiDAR-retrieved backscatter, chlorophyll after using LiDAR calibration constant with inversion results of measured data were within 0.18% and 1.39%, respectively. These findings indicate that the bio-optical methods for LiDAR calibration in clear ocean water are feasible and effective.

show abstract

Optical Backscattering Measured by Airborne Lidar and Underwater Glider

Cited by 26 publications

References 51 publications

Ocean Optical Profiling in South China Sea Using Airborne LiDAR

Ocean Optical Profiling in South China Sea Using Airborne LiDAR

Detection of Chlorophyll a and CDOM Absorption Coefficient with a Dual-Wavelength Oceanic Lidar: Wavelength Optimization Method

A Feasible Calibration Method for Type 1 Open Ocean Water LiDAR Data Based on Bio-Optical Models

Contact Info

Product

Resources

About