{"id":987739,"date":"2026-04-29T10:20:10","date_gmt":"2026-04-29T10:20:10","guid":{"rendered":"https:\/\/david.midstar.com.sa\/?page_id=987739"},"modified":"2026-06-04T13:51:43","modified_gmt":"2026-06-04T13:51:43","slug":"recording-length-and-sample-rate","status":"publish","type":"page","link":"https:\/\/david.midstar.com.sa\/?page_id=987739","title":{"rendered":"Recording length and sample rate"},"content":{"rendered":"\t\t
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\r\n Temporal Signal Processing Matrix<\/span>\r\n

Mechanics of Recording Length & Sampling Rate<\/h1>\r\n

\r\n An engineering deep-dive on discrete temporal digitization thresholds, wave aliasing hazards, and total reflection window calculations in 2D and 3D exploration.\r\n <\/p>\r\n <\/div>\r\n\r\n

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1. Temporal Digitization & The Sampling Rate<\/h2>\r\n

\r\n Seismic instruments do not record a continuous analog line; they convert returning raw acoustic voltage waves into digital data packages by reading amplitude levels at precise time increments called the **Sampling Rate ($\\Delta t$)**. Standard exploration settings utilize intervals of 1, 2, or 4 milliseconds (ms).\r\n <\/p>\r\n

\r\n This choice sets the upper frequency limit for the entire data volume. If the sampling interval is too wide, complex fine-scale high-frequency structures cannot be mapped accurately.\r\n <\/p>\r\n\r\n

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\u0394t<\/div>\r\n <\/div>\r\n
Figure 1: Analog Continuous Waveform vs. Discrete Digital Sample Intervals ($\\Delta t$)<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n
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2. The Nyquist Shannon Criteria & Temporal Aliasing<\/h2>\r\n

\r\n The maximum frequency a digital layout can reconstruct accurately is called the **Nyquist Frequency ($f_N$)**. The math underlying signal preservation defines the limit as exactly one-half cycles per sample unit:\r\n <\/p>\r\n \r\n

\r\n fNyquist<\/sub> = 1 \/ (2 \u2022 \u0394t)\r\n <\/div>\r\n\r\n

\r\n If returning subterranean signal vibrations possess frequencies higher than $f_N$, the wave collapses into **Temporal Aliasing**. The high-frequency wave peaks bypass tracking readouts, appearing in final data storage files as false, distorted low-frequency masks.\r\n <\/p>\r\n\r\n

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\r\n \u25cf High Frequency Wave (Aliased Out)<\/span> \r\n \u25cf Reconstructed False Output Wave<\/span>\r\n <\/div>\r\n
Figure 2: Under-sampling high frequencies results in physical phase identity loss<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n
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3. Calculating Total Target Recording Length<\/h2>\r\n

\r\n **Recording Length ($T$)** represents the duration (in seconds) that the acquisition arrays record incoming ground data after energy discharge. It must be long enough to catch the deepest primary energy reflection plus any late-arriving structures.\r\n <\/p>\r\n

\r\n Total Listening Window (T) \u2265 TWTdeepest<\/sub> + Tmoveout<\/sub> + Tprocessing_window<\/sub>\r\n <\/div>\r\n

\r\n If your recording window cuts off too early, the deepest target reflectors are truncated from your final cross-section. On the other hand, recording for too long increases data storage overhead and inflates processing costs across millions of channels without adding real structural resolution.\r\n <\/p>\r\n <\/div>\r\n\r\n <\/div>\r\n\r\n<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

Temporal Signal Processing Matrix Mechanics of Recording Length & Sampling Rate An engineering deep-dive on discrete temporal digitization thresholds, wave aliasing hazards, and total reflection window calculations in 2D and 3D exploration. 1. Temporal Digitization & The Sampling Rate Seismic instruments do not record a continuous analog line; they convert returning raw acoustic voltage waves…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"footnotes":""},"class_list":["post-987739","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987739","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=987739"}],"version-history":[{"count":4,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987739\/revisions"}],"predecessor-version":[{"id":987860,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987739\/revisions\/987860"}],"wp:attachment":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=987739"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}