Measurement of ocean water optical properties and seafloor reflectance with scanning hydrographic operational airborne lidar survey (SHOALS): II. Practical results and comparison with independent data

Tuell, Grady; Feygels, Viktor; Kopilevich, Yuri; Weidemann, Alan; Cunningham, Alexander; Mani, Reza; Podoba, Vladimir I.; Ramnath, Vinod; Park, J. Y.; Aitken, Jennifer

doi:10.1117/12.619215

Cited by 24 publications

(11 citation statements)

References 2 publications

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“…The effect of parameters listed in Table 3 on the return intensity value will be demonstrated in Equation (4) ( Section 5.2 ). Acquisition geometry parameters must now consider factors such as the bathymetric angle of incidence, or the angle off nadir at which the pulse is transmitted from the aircraft, aircraft altitude, refracted beam angle, and the receiver field of view [ 82 , 83 , 84 , 85 , 86 , 87 ]. The water depth has a significant effect on the power of the return pulse, as the power decays exponentially with depth [ 35 , 84 ].…”

Section: Effective Parameters Influencing Intensity Measurementsmentioning

confidence: 99%

A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

Kashani

Olsen

Parrish

et al. 2015

Sensors

284

214

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In addition to precise 3D coordinates, most light detection and ranging (LIDAR) systems also record “intensity”, loosely defined as the strength of the backscattered echo for each measured point. To date, LIDAR intensity data have proven beneficial in a wide range of applications because they are related to surface parameters, such as reflectance. While numerous procedures have been introduced in the scientific literature, and even commercial software, to enhance the utility of intensity data through a variety of “normalization”, “correction”, or “calibration” techniques, the current situation is complicated by a lack of standardization, as well as confusing, inconsistent use of terminology. In this paper, we first provide an overview of basic principles of LIDAR intensity measurements and applications utilizing intensity information from terrestrial, airborne topographic, and airborne bathymetric LIDAR. Next, we review effective parameters on intensity measurements, basic theory, and current intensity processing methods. We define terminology adopted from the most commonly-used conventions based on a review of current literature. Finally, we identify topics in need of further research. Ultimately, the presented information helps lay the foundation for future standards and specifications for LIDAR radiometric calibration.

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Section: Effective Parameters Influencing Intensity Measurementsmentioning

confidence: 99%

A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

Kashani

Olsen

Parrish

et al. 2015

Sensors

284

214

View full text Add to dashboard Cite

show abstract

“…An improved accuracy is obtained from LIDAR systems only when reliable and precise information of the aircraft location is known at both the transmission and reception times. State-of-the-art LIDAR systems are capable of capturing the reflected signal, as well as providing georeferencing of the three-dimensional coordinates of the laser returns [8][9][10]. The basic concept of operation of a LIDAR is identical to that of conventional radar.…”

Section: Laser Radarsmentioning

confidence: 99%

Airborne laser sensors and integrated systems

Sabatini

Richardson

Gardi

et al. 2015

Progress in Aerospace Sciences

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a b s t r a c tThe underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the development of such requirements, useful guidelines are provided for test and evaluation of airborne laser systems including laboratory, ground and flight test activities.

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“…The resulting images illustrate evolution of the technology from its initial use as a hydrographic survey tool, towards broader acceptance for environmental applications [1,2]. As a next step in this evolution, we endeavor to produce reflectance images in real-time while maintaining the highest possible accuracies.…”

Section: Introductionmentioning

confidence: 98%

New Procedure for Estimating Field-of-View Loss in Bathymetric Lidar

Tuell

Carr

2013

Imaging and Applied Optics

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Bathymetric lidar waveforms may be inverted to generate 3D reflectance images of the shallow-water seafloor. The accuracy of these images is improved when the radiometric inversion accounts for losses arising from the scattering of photons out of the receiver's field of view. Here, we present a new procedure for predicting this loss that is easily implementable in real time. Our technique employs a look-up table containing coefficients for a simple proxy equation yielding loss values that are close approximations to those computed with the full analytical expression for the field of view loss. The coefficients were determined by fitting the proxy equation to thousands of loss functions generated with the full analytical expression wherein we systematically varied geometric and environmental parameters. This work contributes to the goal of generating realtime 3D reflectance images in future bathymetric lidar systems.

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Measurement of ocean water optical properties and seafloor reflectance with scanning hydrographic operational airborne lidar survey (SHOALS): II. Practical results and comparison with independent data

Cited by 24 publications

References 2 publications

A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

Airborne laser sensors and integrated systems

New Procedure for Estimating Field-of-View Loss in Bathymetric Lidar

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