DISCUSSION—MULTIPLE REFLECTIONS

Geophysics ◽  
1948 ◽  
Vol 13 (1) ◽  
pp. 57-57
Author(s):  
C. H. Dresbach
Keyword(s):  
San Joaquin Valley ◽  
Velocity Data ◽  
East Side ◽  
Multiple Reflections ◽  
Multiple Events

In various places along the east side of the San Joaquin Valley, roughly thirty miles north of Bakersfield, reflected events have been observed that plotted below the known top of the basement. Sufficient well and velocity data are available to locate them quite closely. From what is known of the character of the basement material, it appears unlikely that the rather smoothly plotting, fairly continuous events could originate from within the basement. The conclusion is therefore forced that they must represent multiple events of some sort.

MULTIPLE‐REFLECTION EVIDENCE

Geophysics ◽  
1948 ◽  
Vol 13 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Joseph C. Waterman
Keyword(s):  
San Joaquin Valley ◽  
Multiple Reflection ◽  
East Side ◽  
Multiple Reflections ◽  
Basement Complex ◽  
Well Data

A rather interesting example of multiple reflections was found in one area in Madera County on the east side of the San Joaquin Valley of California. In this region the top of the basement complex is an excellent reflecting horizon, and the determination of the depth of the basement was confirmed by well data.

NOTE ON THE CHANGE IN FREQUENCY OF THE REFLECTION FROM BASEMENT AS THIS REFLECTING HORIZON INCREASES IN DEPTH

Geophysics ◽  
1940 ◽  
Vol 5 (2) ◽  
pp. 194-195 ◽  
Author(s):  
Sidon Harris ◽  
N. A. Haskell
Keyword(s):  
San Joaquin Valley ◽  
East Side ◽  
Approximate Representation ◽  
Total Distance

Summary—A table is presented showing the variation in frequency of the reflection obtained from “basement” as this horizon increases in depth. The data were derived from seismograms obtained in the San Joaquin Valley, north of Bakersfield, California. The so‐called “basement” reflecting horizon is followed from a depth of about 1300 feet on the east side to a depth of about 4400 feet farther out toward the middle of the Valley. The results indicate that the frequency of the reflection decreases by about 27 per cent while the depth of the reflecting horizon increases approximately 340 per cent. Gutenberg’s equation, [Formula: see text], where T is the period of the wave, D is the total distance travelled, and a is a constant, gives an approximate representation of these observations if [Formula: see text] and a=0.05 when T is expressed in thousandths of a second and D in feet.

STUDY OF MULTIPLE REFLECTIONS USING A ONE‐DIMENSIONAL SEISMIC MODEL

Geophysics ◽  
1962 ◽  
Vol 27 (1) ◽  
pp. 61-72 ◽  
Author(s):  
A. D. Bennett
Keyword(s):  
Acoustic Pulse ◽  
Seismic Model ◽  
Velocity Data ◽  
Seismic Record ◽  
Multiple Reflections ◽  
One Dimensional ◽  
Well Model ◽  
Seismic Records ◽  
Acoustic Velocities ◽  
Magnetostrictive Transducer

A one‐dimensional seismic model consisting of a multisection metal rod was used in a study of multiple reflections. The model was designed from velocity data provided by an acoustic velocity log. Reflecting interfaces were introduced into the model by changing the rod diameter. An acoustic pulse simulating a shot was applied near the top of the model by a magnetostrictive transducer. Reflections were detected by a crystal receiver placed at the top of the model. Means were devised to achieve an acceptable correspondence in character between a field seismic record obtained at a well site and a synthetic record produced by the model based on acoustic velocities in the well. Model techniques were worked out to separate and identify primary and multiple reflections as an aid in the interpretation of field seismic records.

The San Joaquin Valley East Side Perspective

2006 ◽  
Author(s):  
Walter P. Ward ◽  
William R. Johnston ◽  
Michael Niemi
Keyword(s):  
San Joaquin Valley ◽  
East Side

The Impact of Light Polarisation on Light Field of Scenes with Multiple Reflections

2020 ◽  
pp. 108-115 ◽  
Author(s):  
Vladimir P. Budak ◽  
Anton V. Grimaylo
Keyword(s):  
Mathematical Model ◽  
Light Field ◽  
Global Illumination ◽  
Multiple Reflections ◽  
Software Environment ◽  
The Monte Carlo Method ◽  
Mueller Matrices ◽  
Volume Integration ◽  
The Impact

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

Transportation and the Environment

2017 ◽  
Vol 94 (3) ◽  
pp. 37-61
Author(s):  
Douglas R. Littlefield
Keyword(s):  
Nineteenth Century ◽  
San Francisco ◽  
Sierra Nevada ◽  
Mississippi River ◽  
San Joaquin Valley ◽  
Eastern United States ◽  
Major Health ◽  
San Joaquin River ◽  
Natural Wetlands ◽  
Prevailing View

Some histories of California describe nineteenth-century efforts to reclaim the extensive swamplands and shallow lakes in the southern part of California's San Joaquin Valley – then the largest natural wetlands habitat west of the Mississippi River – as a herculean venture to tame a boggy wilderness and turn the region into an agricultural paradise. Yet an 1850s proposition for draining those marshes and lakes primarily was a scheme to improve the state's transportation. Swampland reclamation was a secondary goal. Transport around the time of statehood in 1850 was severely lacking in California. Only a handful of steamboats plied a few of the state's larger rivers, and compared to the eastern United States, roads and railroads were nearly non-existent. Few of these modes of transportation reached into the isolated San Joaquin Valley. As a result, in 1857 the California legislature granted an exclusive franchise to the Tulare Canal and Land Company (sometimes known as the Montgomery franchise, after two of the firm's founders). The company's purpose was to connect navigable canals from the southern San Joaquin Valley to the San Joaquin River, which entered from the Sierra Nevada about half way up the valley. That stream, in turn, joined with San Francisco Bay, and thus the canals would open the entire San Joaquin Valley to world-wide commerce. In exchange for building the canals, the Montgomery franchise could collect tolls for twenty years and sell half the drained swamplands (the other half was to be sold by the state). Land sales were contingent upon the Montgomery franchise reclaiming the marshes. Wetlands in the mid-nineteenth century were not viewed as they are today as fragile wildlife habitats but instead as impediments to advancing American ideals and homesteads across the continent. Moreover, marshy areas were seen as major health menaces, with the prevailing view being that swampy regions’ air carried infectious diseases.

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