Determination of the signature of a dynamite source using source scaling, Part 1: Theory

Geophysics ◽  
1993 ◽  
Vol 58 (8) ◽  
pp. 1174-1182 ◽  
Author(s):  
Anton Ziolkowski
Keyword(s):  
Impulse Response ◽  
Seismic Data ◽  
Scaling Law ◽  
Cube Root ◽  
The Earth ◽  
Shot Point ◽  
Source Scaling ◽  
Seismic Data Acquisition ◽  
Injection Function

It is normally impossible to measure the source signature in land seismic data acquisition with a dynamite source, because it is normally impossible to separate the incident field from the scattered field. Nevertheless, in any serious attempt to invert the seismic data, it is essential to know the source signature; for the dynamite source this is the volume injection function. The problem can be solved by using two different shots at each shot point and relating the source signatures by the source scaling law, which follows from the invariance of the medium parameters with the size of the charge. The volume injection function of the larger shot is an amplified and stretched version of that of the smaller shot, the amplification factor being equal to the ratio of the charge masses and the time stretch factor being equal to the cube‐root of this ratio. At a given receiver, the response to one shot is a convolution of the source signature with the impulse response of the earth, plus noise. The two shots and the scaling law give three independent equations relating the three unknowns: the two source signatures and the impulse response of the earth (plus noise). This theory may be put at risk in a physical experiment which requires a third shot at the same shot point, using a known mass of dynamite, different from the first two. The resulting shot record should be different from the first two and, apart from the noise, should be predictable from them.

Determination of the signature of a dynamite source using source scaling, Part 2: Experiment

Geophysics ◽  
1993 ◽  
Vol 58 (8) ◽  
pp. 1183-1194 ◽  
Author(s):  
Anton Ziolkowski ◽  
Karel Bokhorst
Keyword(s):  
Seismic Data ◽  
Scaling Law ◽  
Estimation Methods ◽  
Acceptable Error ◽  
Test Charge ◽  
Source Scaling ◽  
Test Record ◽  
Seismic Data Acquisition ◽  
Made In

In April 1990 we performed an experiment in the Netherlands to test the theory of the determination of the signature of a dynamite source using the scaling law. The theory says that the source signature may be determined from the recorded seismic data using two shots of different charge size at the shotpoint; we used 125 g and 500 g charges. The theory was put at risk with a 250-g test charge at each shotpoint. According to the theory, the test record should be different from the other two and, apart from the noise, should be predictable from them. This experiment was repeated 95 times at approximately 50 m shotpoint intervals, using a 240-channel recording system. The results corroborate the theory within an acceptable error. The second‐derivative of the volume injection function was extracted as the source signature; it varied slightly from shot to shot and was minimum phase. This new method of seismic data acquisition allows the signature of the dynamite source to be obtained from the data, uncontaminated by the earth, and avoids the assumptions that must be made in statistical wavelet estimation methods. If there is good shot‐to‐shot repeatability, the second shot is only needed occasionally for calibration.

Can we perform statistical deconvolution by polynomial factorization?

Geophysics ◽  
1991 ◽  
Vol 56 (9) ◽  
pp. 1423-1431 ◽  
Author(s):  
Anton Ziolkowski ◽  
Evert Slob
Keyword(s):  
Impulse Response ◽  
Seismic Data ◽  
Statistical Properties ◽  
Polynomial Factorization ◽  
The Earth ◽  
True Source ◽  
Free Case ◽  
Multichannel Seismic Data

We investigate the possibility of finding the source signature from multichannel seismic data by factorization of the Z-transforms of the seismic traces. In the convolutional model of the data, the source signature is the same from trace to trace within a shot gather, while the impulse response of the earth varies. In the noise‐free case, the roots of the Z-transform of the wavelet are the same from trace to trace, while the roots of the Z-transform of the impulse response of the earth must move from trace to trace. It follows that the roots of the wavelet can be found by the invariance of their positions. We demonstrate this using a simple wedge model. No assumptions about the length of the wavelet or the statistical properties of the impulse response of the earth are required. It is shown that this idea cannot work on real seismic data. There are two difficulties which we regard as insuperable. First, even without noise, a seismic trace cannot be regarded as a complete convolution, because the data are always truncated. This causes the factorization to be inexact: the wavelet roots move from trace to trace and are indistinguishable from the roots of the earth’s impulse response. Second, the addition of a small amount of noise alters the root pattern unpredictably from trace to trace and the roots of the wavelet are again indistinguishable from the roots of the earth’s impulse response. We conclude that it is impossible to identify and extract the true source signature from real seismic data using no assumptions about the statistical properties of the impulse response of the earth. We propose that the signature should be measured.

Reply by the author to the Discussion by J. M. Mendel

Geophysics ◽  
1993 ◽  
Vol 58 (3) ◽  
pp. 443-445
Author(s):  
Anton Ziolkowski
Keyword(s):  
Stochastic Processes ◽  
Seismic Data ◽  
Random Variables ◽  
The Earth ◽  
Definition Of

I thank Professor Mendel for his comments on my paper. I first examine his model of the seismogram and show that losses in the earth cannot be convolutional. I then examine the structure of his “reflectivity sequence” and show that this cannot be random. I suggest that the theory of probability, random variables and stochastic processes is not applicable to our non‐random seismic data. I suggest that we need, and use, a definition of whiteness in geophysics which comes from optics. Finally I show that none of the methods I am proposing for the determination of the source signature relies on the earth being loss‐free.

Estimation of source signatures from air guns fired at various depths: A field test of the source scaling law

Geophysics ◽  
2016 ◽  
Vol 81 (3) ◽  
pp. P13-P22 ◽  
Author(s):  
Kjetil E. Haavik ◽  
Martin Landrø
Keyword(s):  
Correction Term ◽  
Near Field ◽  
Scaling Law ◽  
Field Measurements ◽  
Air Gun ◽  
Time Period ◽  
Source Scaling ◽  
Seismic Data Acquisition ◽  
The Difference ◽  
The Given

Recent advances in marine broadband seismic data acquisition have led to a range of new air-gun source configurations. The air-gun arrays have conventionally been kept at a constant depth, but to attenuate the source-side ghost reflection, new source strategies involving multiple source depths have been proposed. The bubble-time period for an air-gun bubble is dependent on, among many parameters, the firing depth. We use quasi near-field measurements of air-gun signatures to validate a version of the well-known source scaling law in which the characteristic bubble-time period is used as the scale. We find that the source scaling law can be used to estimate a source signature from one depth knowing the source signature at a different depth from the same gun. Furthermore, we derive a correction term to the Rayleigh-Willis bubble-time equation to correct for the fact that interaction between the bubble and free surface reduces the bubble-time period. This correction term improves our results significantly for air guns positioned close to the air-water interface. The error between the estimated and measured source signatures is dependent on the difference in source depth. For a depth difference of [Formula: see text], we estimate signatures that have NRMS differences ranging between 5% and 6% from the measured signature at the given depth and between 8% and 12% when the difference is [Formula: see text].

HADIS KURAIB DALAM KONSEP RUKYATUL HILAL

1970 ◽  
Vol 13 (2) ◽  
Author(s):  
Muslih Husein
Keyword(s):  
The West ◽  
The Earth ◽  
New Moon ◽  
The Republic

Hisab dan rukyat, hakikatnya, adalah cara untuk mengetahui pergantian bulan. Kajian ini memperlihatkan beberapa temuan. Pertama, korelasi antara hadis Kuraib dan terjadinya perbedaan penetapan awal Ramadan, Syawal, dan Dzul Hijjah di Indonesia. Kementerian Agama Republik Indonesia telah menetapkan bahwa Indonesia secara keseluruhan menjadi satu wilayah hukum (wilayatul hukmi). Kedua, tentang keberhasilan rukyat al-hilal di satu kawasan yang diberlakukan bagi kawasan lain di muka bumi. Perlu diketahui bersama bahwa visibilitas pertama hilal tidak meliputi seluruh muka bumi pada hari yang sama, melainkan membelahnya menjadi dua bagian: (1) bagian sebelah Barat yang dapat melihat hilal dan (2) bagian sebelah Timur yang tidak dapat melihat hilal.Hisab and rukyat is a way to know the turn of the month. This study shows several findings. First is the correlation between Kuraib traditions and differences in the determination of the beginning of Ramadan, Shawwal, and Dhul-Hijjah in Indonesia. Ministry of Religious Affairs of the Republic of Indonesia has stated that Indonesia as a whole into a single jurisdiction (wilayatul hukmi). Second, on the success rukyat alhilal in one area that applied to other regions of earth. Important to know that the first visibility of the new moon does not cover the entire face of the earth on the same day, but splitting it into two parts: (1) part of the West to see the new moon, and (2) part of the East were not able to see the new moon.

Forecasting the fl ood situation using space images in the city of Tavda Sverdlovsk region

2018 ◽  
Vol 934 (4) ◽  
pp. 46-52
Author(s):  
A.S. Bruskova ◽  
T.I. Levitskaya ◽  
D.M. Haydukova
Keyword(s):  
Water Levels ◽  
Economic Damage ◽  
Geoinformation System ◽  
Space Images ◽  
Geoinformation Systems ◽  
Emergency Situations ◽  
The Earth ◽  
Maximum Water ◽  
The City

Flooding is a dangerous phenomenon, causing emergency situations and causing material damage, capable of damaging health, and even death of people. To reduce the risk and economic damage from flooding, it is necessary to forecast flooding areas. An effective method of forecasting emergency situations due to flooding is the method of remote sensing of the Earth with integration into geoinformation systems. With the help of satellite imagery, a model of flooding was determined based on the example of Tavda, the Sverdlovsk Region. Space images are loaded into the geoinformation system and on their basis a series of thematic layers is created, which contains information about the zones of possible flooding at given water level marks. The determination of the area of flooding is based on the calculation of the availability of maximum water levels at hydrological stations. According to the calculated security data, for each hydrological post, flood zones are constructed by interpolation between pre-calculated flood zones of standard security. The results of the work can be used by the Main Directorate of the Ministry for Emergency Situations of Russia for the Sverdlovsk Region.

Effects of incomplete parameterization on full-wavefield viscoelastic seismic data for petrophysical reservoir properties

Geophysics ◽  
2007 ◽  
Vol 72 (3) ◽  
pp. O9-O17 ◽  
Author(s):  
Upendra K. Tiwari ◽  
George A. McMechan
Keyword(s):  
Seismic Data ◽  
Input Data ◽  
Elastic Model ◽  
Quality Factors ◽  
Noise Levels ◽  
Reservoir Properties ◽  
Estimated Parameters ◽  
Model Parameterization ◽  
The Earth ◽  
Incomplete Model

In inversion of viscoelastic full-wavefield seismic data, the choice of model parameterization influences the uncertainties and biases in estimating seismic and petrophysical parameters. Using an incomplete model parameterization results in solutions in which the effects of missing parameters are attributed erroneously to the parameters that are included. Incompleteness in this context means assuming the earth is elastic rather than viscoelastic. The inclusion of compressional and shear-wave quality factors [Formula: see text] and [Formula: see text] in inversion gives better estimates of reservoir properties than the less complete (elastic) model parameterization. [Formula: see text] and [Formula: see text] are sensitive primarily to fluid types and saturations. The parameter correlations are sensitive also to the model parameterization. As noise increases in the viscoelastic input data, the resolution of the estimated parameters decreases, but the parameter correlations are relatively unaffected by modest noise levels.

scholarly journals Determination of underground voids in the surface of the earth section

2021 ◽  
Vol 1942 (1) ◽  
pp. 012085
Author(s):  
G A Pchelkin ◽  
A S Grevtseva ◽  
M V Diuldin
Keyword(s):  
The Earth
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