scholarly journals Identifying lakebed nature: is it feasible with a combination of echosounder and Sonar5-pro?

2011 ◽  
Vol 2 (1) ◽  
pp. 49
Author(s):  
Thomas Poulain ◽  
Christine Argillier ◽  
Muriel Gevrey ◽  
Jean Guillard
Keyword(s):  
Signal Processing ◽  
Arctic Charr ◽  
Video Camera ◽  
Fish Biomass ◽  
Post Processing ◽  
Single Beam ◽  
Optimum Configuration ◽  
Processing Software ◽  
Bottom Grab

Since a few decades, underwater substrata can be characterized by methods using acoustic technology. Compare to traditional in situ grabbing techniques (bottom grab sampler, video camera, …), these methods allow a better spatial resolution. Until today, these acoustical techniques required specialized signal processing materials. This document presents works about lakebed classification using single beam echo sounder and a post processing software (Sonar5) dedicated to the estimation of fish biomass. Indeed, an underwater substrate analyzing module based on the theory developed by Orlowski (Oceanologia 19 (1984), pp. 61–78) has just been implemented in the sofware. An optimum configuration have been selected and permitted to classify four different natures of substrata: silt, sand, sand & stones, and rock. A substrata nature map of an area known as an arctic charr (emblematic salmonid of the alpine big lakes) reproduction site has been done and shows the system's performances.

scholarly journals In situ measurements of firn compaction profiles using borehole optical stratigraphy

2011 ◽  
Vol 57 (202) ◽  
pp. 289-294 ◽  
Author(s):  
Robert L. Hawley ◽  
Edwin D. Waddington
Keyword(s):  
Steady State ◽  
Depth Distribution ◽  
Vertical Motion ◽  
Video Camera ◽  
Survey Period ◽  
The Past ◽  
Steady State Model ◽  
Processing Software ◽  
Optical Brightness

AbstractWe have developed a technique in which we use a borehole video camera and post-processing software to make a record of the optical brightness as a function of depth in polar firn. We call this method borehole optical stratigraphy. To measure firn compaction, we note the positions of optical features on the borehole wall detected by an initial ‘baseline’ log. We track the displacements of these features in subsequent logs. The result provides a measurement of the relative vertical motion and thus compaction of the firn over the survey period. We have successfully used this system at Summit, Greenland, to measure the depth distribution of firn column shortening experienced in a borehole over three 1 year periods. The uppermost 30 m of the firn at Summit is compacting as predicted by a simple steady-state model, implying that the firn density profile at Summit is at or close to steady state over the past ∼70 years.

Deteksi Bentuk Objek Bawah Tanah Menggunakan Pengolahan Citra B-Scan pada Ground Penetrating Radar (GPR)

2017 ◽  
Vol 3 (1) ◽  
pp. 73-83
Author(s):  
Rahmayati Alindra ◽  
Heroe Wijanto ◽  
Koredianto Usman
Keyword(s):  
Signal Processing ◽  
Ground Penetrating Radar ◽  
Post Processing ◽  
Data Survey ◽  
Ground Penetrating

Ground Penetrating Radar (GPR) adalah salah satu jenis radar yang digunakan untuk menyelidiki kondisi di bawah permukaan tanah tanpa harus menggali dan merusak tanah. Sistem GPR terdiri atas pengirim (transmitter), yaitu antena yang terhubung ke generator sinyal dan bagian penerima (receiver), yaitu antena yang terhubung ke LNA dan ADC yang kemudian terhubung ke unit pengolahan data hasil survey serta display sebagai tampilan output-nya dan post  processing untuk alat bantu mendapatkan informasi mengenai suatu objek. GPR bekerja dengan cara memancarkan gelombang elektromagnetik ke dalam tanah dan menerima sinyal yang dipantulkan oleh objek-objek di bawah permukaan tanah. Sinyal yang diterima kemudian diolah pada bagian signal processing dengan tujuan untuk menghasilkan gambaran kondisi di bawah permukaan tanah yang dapat dengan mudah dibaca dan diinterpretasikan oleh user. Signal processing sendiri terdiri dari beberapa tahap yaitu A-Scan yang meliputi perbaikan sinyal dan pendektesian objek satu dimensi, B-Scan untuk pemrosesan data dua dimensi  dan C-Scan untuk pemrosesan data tiga dimensi. Metode yang digunakan pada pemrosesan B-Scan salah satunya adalah dengan  teknik pemrosesan citra. Dengan pemrosesan citra, data survey B-scan diolah untuk didapatkan informasi mengenai objek. Pada penelitian ini, diterapkan teori gradien garis pada pemrosesan citra B-scan untuk menentukan bentuk dua dimensi dari objek bawah tanah yaitu persegi, segitiga atau lingkaran. 

ARSRP Signal Processing Software

1993 ◽  
Author(s):  
Lisa Pflug ◽  
Jerald W. Caruthers ◽  
Richard R. Slater
Keyword(s):  
Signal Processing ◽  
Processing Software

scholarly journals Formation of compact systems of super-Earths via dynamical instabilities and giant impacts

2019 ◽  
Vol 491 (4) ◽  
pp. 5595-5620 ◽  
Author(s):  
Sanson T S Poon ◽  
Richard P Nelson ◽  
Seth A Jacobson ◽  
Alessandro Morbidelli
Keyword(s):  
Initial Conditions ◽  
Post Processing ◽  
Significant Modification ◽  
Kepler Mission ◽  
Giant Impacts ◽  
Low Mass ◽  
In Situ Formation ◽  
Dynamical Instabilities ◽  
Gaseous Envelopes

ABSTRACT The NASA’s Kepler mission discovered ∼700 planets in multiplanet systems containing three or more transiting bodies, many of which are super-Earths and mini-Neptunes in compact configurations. Using N-body simulations, we examine the in situ, final stage assembly of multiplanet systems via the collisional accretion of protoplanets. Our initial conditions are constructed using a subset of the Kepler five-planet systems as templates. Two different prescriptions for treating planetary collisions are adopted. The simulations address numerous questions: Do the results depend on the accretion prescription?; do the resulting systems resemble the Kepler systems, and do they reproduce the observed distribution of planetary multiplicities when synthetically observed?; do collisions lead to significant modification of protoplanet compositions, or to stripping of gaseous envelopes?; do the eccentricity distributions agree with those inferred for the Kepler planets? We find that the accretion prescription is unimportant in determining the outcomes. The final planetary systems look broadly similar to the Kepler templates adopted, but the observed distributions of planetary multiplicities or eccentricities are not reproduced, because scattering does not excite the systems sufficiently. In addition, we find that ∼1 per cent of our final systems contain a co-orbital planet pair in horseshoe or tadpole orbits. Post-processing the collision outcomes suggests that they would not significantly change the ice fractions of initially ice-rich protoplanets, but significant stripping of gaseous envelopes appears likely. Hence, it may be difficult to reconcile the observation that many low-mass Kepler planets have H/He envelopes with an in situ formation scenario that involves giant impacts after dispersal of the gas disc.

scholarly journals DSPSR: Digital Signal Processing Software for Pulsar Astronomy

2011 ◽  
Vol 28 (1) ◽  
pp. 1-14 ◽  
Author(s):  
W. van Straten ◽  
M. Bailes
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Graphics Processing Units ◽  
High Performance ◽  
Digital Signal ◽  
General Purpose ◽  
Design Decisions ◽  
Extensive Range ◽  
Processing Software ◽  
Graphics Processing

Abstractdspsr is a high-performance, open-source, object-oriented, digital signal processing software library and application suite for use in radio pulsar astronomy. Written primarily in C++, the library implements an extensive range of modular algorithms that can optionally exploit both multiple-core processors and general-purpose graphics processing units. After over a decade of research and development, dspsr is now stable and in widespread use in the community. This paper presents a detailed description of its functionality, justification of major design decisions, analysis of phase-coherent dispersion removal algorithms, and demonstration of performance on some contemporary microprocessor architectures.

scholarly journals Location of agate geodes in Permian deposits of Simota gully using the GPR

2021 ◽  
Author(s):  
Michał Mierczak ◽  
Jerzy Karczewski
Keyword(s):  
Signal Processing ◽  
High Frequency ◽  
Electromagnetic Energy ◽  
Reflection Coefficients ◽  
Electric Permittivity ◽  
Pyroclastic Deposits ◽  
High Attenuation ◽  
Subsurface Geology ◽  
Study Test

AbstractThe article describes the establishment of the location of agate geodes using the GPR method in the area of the Simota gully (Lesser Poland Voivodeship). Agates (a multicolored variety of gemstone of chalcedony group) have multifaceted values that informed their study. Traditional methods of geode location are less reliable, hence the attempt to use the GPR method. Measurements were taken at two study test sites with subsurface geology of weathered melaphyre and pyroclastic deposits using a GPR system (ProEx). A high-frequency antenna (1.6 GHz) was used along with the pre-established profiles of lengths of 6-m and 10-cm intervals. Furthermore, simple soil tests using the soil sampler tool were made prior to the GPR measurement. The GPR results show significant high attenuation of the electromagnetic energy interpreted to be due to clay components of the regolith. Advanced signal processing procedures (such as the attribute of the signal) were used on the data for better enhancement that aided interpretation. Other anomalies depicted on the radargrams were thought to be the presence of roots, pieces of melaphyres-targeted agates. Furtherance to ascertain the reflection coefficients as recorded on the GPR data, in situ samples (root pieces, melaphyres, agates) taken were tested in the laboratory for electric permittivity property. Based on the interpretation results, several agate geodes were dug out from the ground.

In Situ Observation Method for Quantitative Evaluation of Solidification Phenomena and Solidification Cracks during Welding

2014 ◽  
Vol 782 ◽  
pp. 3-7
Author(s):  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kohta Kadoi ◽  
Peng Wen
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Solidification Cracking ◽  
In Situ Observation ◽  
High Speed Video Camera ◽  
Varestraint Test ◽  
Solidification Cracks ◽  
Observation Method ◽  
Solidification Crack

Solidification cracking during welding is very serious problem for practical use. Therefore, there are so many reports concerning solidification cracking. Normally, solidification cracking susceptibility of material is quantitatively evaluated using Trans-Varestraint test. On the other hand, local solidification cracking strain was tried to measure precisely using in-situ observation method, called MISO method about 30 years ago. Recently, digital high-speed video camera develops very fast and its image quality is very high. Therefore, we have started to observe solidification crack using in site observation method. In this paper, the local critical strain of a solidification crack was measured and the high temperature ductility curves of weld metals having different dilution ratios and different grain sizes to evaluate quantitatively the effects of dilution ratio and grain size on solidification cracking susceptibility by using an improved in situ observation method.

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