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DEPRECATED: This module is deprecated and should not be used in new processing workflows. It is retained only for compatibility with legacy projects.
The VINT T to and from VINT Z (2D) module converts 2D interval velocity gathers between the time domain and the depth domain. Given an interval velocity field defined as a function of two-way time (VINT-T), the module can compute the equivalent interval velocity as a function of depth (VINT-Z), or perform the inverse conversion from VINT-Z back to VINT-T. The conversion accounts for a user-defined datum and replacement velocity to handle the near-surface layer.
The time-to-depth conversion uses the interval velocity itself to integrate travel time and compute depth. The depth-to-time conversion performs the inverse integration. Both directions use the replacement velocity below the datum if no explicit datum is provided. The module processes all traces in the input gather or a specified trace range, and can optionally restrict interval velocity decreases to improve stability.
The input 2D interval velocity gather. Each trace in the gather represents the interval velocity profile at one CMP location. For Time to Depth conversion, the gather is in the time domain (VINT-T); for Depth to Time conversion, the gather is in the depth domain (VINT-Z).
The maximum output depth extent (in metres) when converting from time to depth. Default: -1, which causes the module to automatically determine the maximum depth from the integral of the input interval velocity over the full record length. Set this explicitly if you require a fixed depth range, for example to match the depth extent of a depth-migrated volume.
The maximum output two-way time (in seconds) when converting from depth to time. Default: -0.001, which causes the module to automatically compute the maximum time from the depth extent and the input velocity values. Set this explicitly to match the record length of the target time-domain data.
The time sample interval for the output velocity traces when converting in the Depth to Time direction, in seconds. Default: 0.004 s (4 ms). Set this to match the sample interval of the seismic data that will use the output velocity field.
The depth sample interval for the output velocity traces when converting in the Time to Depth direction, in metres. Default: 0.005 m. In practice, use values such as 1 m or 5 m to match the depth sampling of the target depth-domain model. A finer dz gives smoother output but increases file size.
Selects the conversion direction. Default: Time to Depth.
Time to Depth — converts an interval velocity field defined as a function of two-way time into the equivalent field defined as a function of depth. The output dz parameter controls the depth sampling of the result.
Depth to Time — converts a depth-domain interval velocity field back into the time domain. The output dt parameter controls the time sampling of the result.
The reference datum elevation (in metres) for the near-surface replacement velocity layer. Default: -99999.9, which causes the datum to be determined automatically from the trace elevation headers. Set this explicitly to apply a fixed processing datum consistent with the rest of the processing flow.
The velocity (in m/s) assumed for the near-surface layer between the acquisition surface and the datum. Default: 1500 m/s. This value is used to compute travel time through the weathering or near-surface layer during the time–depth conversion. Use the local near-surface or replacement velocity from the statics solution for the survey.
Specifies whether the input velocity field is referenced to the acquisition topography surface or to the processing datum. Default: Datum. Set to Topography if the input velocity starts at the receiver elevation; set to Datum if the input velocity starts at the flat processing datum level.
Controls which traces in the input gather are processed. Default: All. Set to Range to process only a subset of traces defined by the 1st trace and Last trace parameters. This is useful for testing or for converting only a portion of a large velocity gather.
The index of the first trace to process when Traces is set to Range. Default: -1 (process from the first available trace). Trace numbering starts from 0.
The index of the last trace to process when Traces is set to Range. Default: -1 (process up to the last available trace). Set this together with 1st trace to restrict conversion to a specific CMP range within the 2D line.