Sökning: onr:"swepub:oai:DiVA.org:ltu-10428" > Weighted vertical s...
Fältnamn | Indikatorer | Metadata |
---|---|---|
000 | 03451naa a2200349 4500 | |
001 | oai:DiVA.org:ltu-10428 | |
003 | SwePub | |
008 | 160929s1977 | |||||||||||000 ||eng| | |
024 | 7 | a https://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-104282 URI |
024 | 7 | a https://doi.org/10.1111/j.1365-2478.1977.tb01166.x2 DOI |
040 | a (SwePub)ltu | |
041 | a engb eng | |
042 | 9 SwePub | |
072 | 7 | a ref2 swepub-contenttype |
072 | 7 | a art2 swepub-publicationtype |
100 | 1 | a Brown, R.J.u Luleå tekniska universitet,NTNF/NORSAR, Kjeller, Norway4 aut |
245 | 1 0 | a Weighted vertical stacking in crustal seismic reflection studies on the Canadian shield |
264 | 1 | b Wiley,c 1977 |
338 | a print2 rdacarrier | |
500 | a Godkänd; 1977; 20120105 (andbra) | |
520 | a Seismic reflection methods are being developed at the University of Manitoba to aid in determining fine crustal structures in the Precambrian of Manitoba and northwestern Ontario. Present-day environmental concern as well as mineshaft conditions necessitate the detonation of several smaller charges repeated, say, I times and followed by ''vertical'' stacking. To obtain the familiar ..sqrt..I improvement in signal-to-noise (S : N) amplitude ratio applying the straight-sum (SS) method, one assumes, among other things, that both S : N ratio and signal variance are the same on all traces. Dropping these assumptions, as we must for our data, it becomes necessary to apply weighting coefficients to optimize the S : N ratio of the stacked trace. We still assume the signal shapes to be the same for repeated shots, so for the jth trace on the record of the ith shot we model the time series as: t/sub ij/ = a/sub i/(s/sub j/ + n/sub ij/); where a/sub i/ is a scaling factor. The proper weights w/sub i/ are then shown to be proportional to sigma/sub si//sigma/sup 2//sub ni/ where sigma/sup 2/ is variance, or to ..gamma../sub i//a/sub i/ where ..gamma../sub i/ is S : N power ratio. Applying the weighted-stack (WS) method gives S : N amplitude ratios which are, on average, 55% of the optimal ratios expected from WS theory compared with only 24% for the SS method. The 45% shortfall in WS performance is ascribed mainly to trace-alignment (or time-delay) errors. Varying noise levels on individual traces, slight dissimilarity of signal shape, and correlated noise may also contribute to a lesser extent (in decreasing order of significance). This WS method appears to strike a good practical balance between S : N improvement and processing efficiency. | |
650 | 7 | a NATURVETENSKAPx Geovetenskap och miljövetenskapx Geokemi0 (SwePub)105062 hsv//swe |
650 | 7 | a NATURAL SCIENCESx Earth and Related Environmental Sciencesx Geochemistry0 (SwePub)105062 hsv//eng |
653 | a Applied Geology | |
653 | a Tillämpad geologi | |
700 | 1 | a Friesen, G.H.u Gulf Oil Canada Limited, University of Manitoba, Calgary, Alberta, Canada4 aut |
700 | 1 | a Hall, D.H.u Department of Earth Sciences, University of Manitoba, Manitoba, Canada4 aut |
700 | 1 | a Stephenson, O.G.u Department of Earth Sciences, University of Manitoba, Manitoba, Canada4 aut |
710 | 2 | a Luleå tekniska universitetb NTNF/NORSAR, Kjeller, Norway4 org |
773 | 0 | t Geophysical Prospectingd : Wileyg 25:2, s. 251-268q 25:2<251-268x 0016-8025x 1365-2478 |
856 | 4 8 | u https://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-10428 |
856 | 4 8 | u https://doi.org/10.1111/j.1365-2478.1977.tb01166.x |
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
Kopiera och spara länken för att återkomma till aktuell vy