Unique common mid-point (cmp) navigation for multi-channel seismic data collected by the U.S. Geological Survey on U.S. Atlantic Seaboard in 2014 (Geographic, WGS84, point shapefile 2014-011-FA_mcscmp.shp)

Navigation was acquired using the R/V Marcus G. Langseth's fully integrated multicomponent navigation system, consisting of echosounder, speedlog, Differential Global Positioning System (DGPS), gyrocompass, POS/MV Integrated Navigation System, Kongsberg Seapath 200 Inertial Navigation System and Lamont Data Systems (LDS) data logger. Source and receiver positions were determined by LDEO staff using Concept Systems's Spectra multichannel seismic navigation software. Source positions were logged using differential GPS antennas on three of the four source sub arrays. Receiver positions were calculated using data from Digicourse Digirange acoustic pods on the source array and on the head, middle, and tail of the streamer; depth and heading data from Digicourse depth control birds located every 300 m along the streamer; and a differential GPS on the streamer tail buoy. All survey positions use the World Geodetic System 1984 datum (WGS84), and both global and local geodetic calculations utilized the WGS84 reference ellipsoid with a semi-major axis of 6378137.0 m and an inverse flattening of 298.257224. Streamer geometry calculations were performed in Universal Transverse Mercator (UTM) northern hemisphere projection 19 North . Source-receiver midpoints were calculated using source and receiver positions from the processed P190 seismic navigation. All midpoint and bin calculations were made in UTM 19N coordinates using Shearwater’s OpenCPS (version 3.3.0) seismic processing software. To handle extreme streamer feathering, CMP bin assignments were made using 1000-m wide rectangular bins spaced every 6.25m along prescribed CMP lines. Midpoints that fall outside these 6.25x1000m bins were assigned CMP=0 and were excluded from processing. CMP lines were drawn to maximize the number of midpoints from source-receiver offsets of <1000m in each bin (i.e., fold).

SEG-D format shot gathers were imported into OpenCPS (version 3.3.0) software, and processed through a standard sequence of trace editing, common-midpoint (CMP) sorting, bandpass filtering, deconvolution, velocity analysis, normal moveout correction, stretch muting, stacking, and post-stack time migration. True group and source locations were taken from the P190 navigation files provided by the crew of the R/V Marcus Langseth. Files were written to SEG-Y format using OpenCPS (version 3.3.0) seismic proicessing software. Processing step specifics are written into the SEG-Y text header for each line:
Description Post-stack phase shift time migration to 200 Hz using auto-picked velocities guided by a 1D velocity function hung between picked water-bottom, basement, and Moho.
This is an example from line MGL1407MCS03:
Prestack gains: Spherical divergence Poststack gains: None Band: 6-200 Hz
Cruise:MGL1407 Line:MGL1407MCS03 Coordinate projection:WGS84/UTM 19N ESPG:32619 WKT:"+proj=utm +zone=19 +datum=WGS84 +units=m +no_defs"
Nathan C. Miller performed this and all subsequent process steps.

Coordinates were converted to Universal Transverse Mercator (UTM) northern hemisphere projection 19 North for streamer geometry calculations (calculation of cmp position). While the data extends beyond the singular UTM Zone 19N, the selected UTM zone is central to the majority of the data. Projected coordinates are often used for binning, and CMP calculation as the units (meters) are easier to use than fractional degrees of latitude and longitude. CMP locations were converted back to geographic coordinates. CMP locations were written as geographic coordinates (WGS84) to a text file (*.csv) using a Python script within OpenCPS (version 3.3.0) , and then imported into Esri ArcMap 10.3 using ArcCatalog, Create Feature Class from XY Table, specifying geographic coordinates, WGS84 coordinate system (EPSG code 4326).

An error was fixed in one of the originator names. Also fixed in the suggested citation.

Added keywords section with USGS persistent identifier as theme keyword.