Echo grid integration: A novel method for preprocessing multibeam water column data to quantify underwater gas bubble emissions
نویسندگان
چکیده
Water column imaging multibeam echo sounder systems (MBESs) are a promising technology for quantitative estimates of the gas bubble volume flow within large seepage areas. Considerable progress has been made in recent years toward applicable calibration methods MBESs as well developing inversion models to convert acoustically measured backscattering cross sections flow. However, still not commonly used assessments. A reason this is absence published processing that demonstrate how MBES data can be processed quantitatively represent streams. Here, we present novel method (echo grid integration) allows assessing aggregated section targets horizontal water layers. This derived value enables quantifying stream rates using existing acoustic methods. The presented based on averaging geo-referenced coefficients onto high-resolution 3D voxel-grid. results multiplied with voxel measurements total cross-section each cell. Individual gridded values cannot trusted because beam pattern effects cause individual “smear” over multiple grid-cells. true thus estimated integral grid-cells affected by smearing. Numerical simulation acquisition known assesses method's validity and quantify it's uncertainty different, realistic scenarios. found low measurement bias (< 1%), dispersion 5%) application quantification
منابع مشابه
Technical Note: Detection of gas bubble leakage via correlation of water column multibeam images
Hydroacoustic detection of natural gas release from the seafloor has been conducted in the past by using singlebeam echosounders. In contrast, modern multibeam swath mapping systems allow much wider coverage, higher resolution, and offer 3-D spatial correlation. Up to the present, the extremely high data rate hampers water column backscatter investigations and more sophisticated visualization a...
متن کاملa new approach to credibility premium for zero-inflated poisson models for panel data
هدف اصلی از این تحقیق به دست آوردن و مقایسه حق بیمه باورمندی در مدل های شمارشی گزارش نشده برای داده های طولی می باشد. در این تحقیق حق بیمه های پبش گویی بر اساس توابع ضرر مربع خطا و نمایی محاسبه شده و با هم مقایسه می شود. تمایل به گرفتن پاداش و جایزه یکی از دلایل مهم برای گزارش ندادن تصادفات می باشد و افراد برای استفاده از تخفیف اغلب از گزارش تصادفات با هزینه پائین خودداری می کنند، در این تحقیق ...
15 صفحه اولComprehensive Detection of Gas Plumes from Multibeam Water Column Images with Minimisation of Noise Interferences
Multibeam echosounder systems (MBES) can record backscatter strengths of gas plumes in the water column (WC) images that may be an indicator of possible occurrence of gas at certain depths. Manual or automatic detection is generally adopted in finding gas plumes, but frequently results in low efficiency and high false detection rates because of WC images that are polluted by noise. To improve t...
متن کاملA method for bubble volume measurement under constant flow conditions in gas–liquid two-phase flow
Measuring the volume of a bubble, especially at its detachment, is a basic subject in gas-liquid two-phase flow research. A new indirect method for this measurement under constant flow conditions is presented. An electronic device is designed and constructed based on laser beam intensity. This device calculates the frequency of the bubble formation by measuring the total time of the formation p...
متن کاملA Novel Detection Method for Underwater Moving Targets by Measuring Their ELF Emissions with Inductive Sensors
In this article, we propose a novel detection method for underwater moving targets by detecting their extremely low frequency (ELF) emissions with inductive sensors. The ELF field source of the targets is modeled by a horizontal electric dipole at distances more than several times of the targets' length. The formulas for the fields produced in air are derived with a three-layer model (air, seaw...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Limnology and Oceanography-methods
سال: 2023
ISSN: ['1541-5856']
DOI: https://doi.org/10.1002/lom3.10552