DOI: 10.5061/dryad.d2547d8d3
title: Raw GPR data for: Alluvial dynamics of a formerly glaciated Rocky Mountain headwater valley, Colorado

description: This dataset includes raw common-offset ground-penetrating radar (GPR)
 lines crossing the South Fork River Valley, Colorado (please see
 GPR_Profile_Line_Map.png for a figure detailing the line names and
 locations). These GPR lines were merged in processing to generated the
 Profiles (1-4) presented in the manuscript. We used a Sensors and Software
 DVL and 100 MHz frequency antennas spaced 1 m apart, arranged
 perpendicular to the direction of travel, with a trace spacing of 0.25 m
 along a reel tape placed along the transect path. A single Emlid Reach RS2
 GPS receiver with an accuracy of 2.5 m was mounted to the GPR frame and
 recorded the position of each trace. Ringing artifacts from a metal GPS
 mount occurred on initial transects but the mount was subsequently
 replaced by a plastic mount. Frequency filtering was unsuccessful at
 removing instrument noise without removing the real signal observed close
 to the ground surface. Over 1.5 km of common offset GPR data were
 collected along the transects. We conducted two common midpoint (CMP)
 surveys to estimate radar velocities in valley bottom sediments to improve
 the accuracy of the travel time to depth conversion of cross sectional
 radargrams. The CMP surveys used a 10 cm move out of each antenna between
 each trace. Sixty traces were collected in each CMP survey.
description: # Alluvial dynamics of a formerly glaciated Rocky Mountain headwater
 valley, Colorado Dataset DOI:
 [10.5061/dryad.d2547d8d3](10.5061/dryad.d2547d8d3) ## Description of the
 data and file structure We used a Sensors and Software PulseEkko GPR
 system to conduct common offset surveys to create quasi two-dimensional
 images of the subsurface at transects crossing the South Fork River
 Valley. Common-offset GPR surveys image the subsurface at a resolution
 that documents vertical changes in subsurface characteristics, as captured
 via coring, but also the horizontal stratigraphy contained within the
 substrate. For common offset surveys, we used 100 MHz frequency antennas
 spaced 1 m apart, arranged perpendicular to the direction of travel, with
 a trace spacing of 0.25 m along a reel tape placed along the transect
 path. A single Emlid Reach RS2 GPS receiver with an accuracy of 2.5 m was
 mounted to the GPR frame and recorded the position of each trace. Ringing
 artifacts from a metal GPS mount occurred on initial transects but the
 mount was subsequently replaced by a plastic mount. Frequency filtering
 was unsuccessful at removing instrument noise without removing the real
 signal observed close to the ground surface. Over 1.5 km of common offset
 GPR data were collected along the transects. We conducted two common
 midpoint (CMP) surveys to estimate radar velocities in valley bottom
 sediments to improve the accuracy of the travel time to depth conversion
 of cross sectional radargrams. The CMP surveys used a 10 cm move out of
 each antenna between each trace. Sixty traces were collected in each CMP
 survey. The files are labeled date \_ *line#* \_*file extension.  For
 example, 0701_Line1*_dt.1 was collected on 01 July and is Line 1 and is a
 .dt1 file.  For each line, there are four primary files: a .dt1, a .hd, a
 .ini and a .gp2.  Some lines also contain a .int file. The .dt1 file is
 the ground-penetrating radar binary file containing the radargram, the .hd
 is a header text file containing the instrument and collection parameters
 (e.g., number of traces, antenna separation, number of stacks), .ini is a
 text file containing the configuration settings for the radar collection,
 and .gp2 is a text file containing the GPS positioning (trace #, latitude,
 longitude, and elevation referenced to WGS84 ellipsoid). The .int file is
 an interpretation/marker file that was used to mark specific locations in
 the radargrams relative to notable features in the field.  Please see
 GPR_*Profile_Line*_Map.png for a map of GPR profiles (as described in the
 paper) and the associated line numbers. The GPR data were processed using
 the ReflexW software package (Sandmeier, 2019) to remove low-frequency
 (i.e. dewow) signals recorded by the system and to apply a uniform time
 zero correction to align the surface of the radargram with ground surface.
 Additional software suggestions are included at the end of this README
 file. ### Files and variables 0701_line1.dt1 0701_line1.gp2 0701_line1.hd
 0701_line1.ini 0701_line10.dt1 0701_line10.gp2 0701_line10.hd
 0701_line10.ini 0701_line11.dt1 0701_line11.gp2 0701_line11.hd
 0701_line11.ini 0701_line12.gp2 0701_line12.hd 0701_line12.ini
 0701_line12.int 0701_line16.dt1 0701_line16.gp2 0701_line16.hd
 0701_line16.ini 0701_line16.int 0701_line6_cmp.dt1 0701_line6_cmp.gp2
 0701_line6_cmp.hd 0701_line6_cmp.ini 0701_line8.dt1 0701_line8.gp2
 0701_line8.hd 0701_line8.ini 0701_line9.dt1 0701_line9.gp2 0701_line9.hd
 0701_line9.ini 1106_line2.dt1 1106_line2.gp2 1106_line2.hd 1106_line2.ini
 1106_line3.dt1 1106_line3.gp2 1106_line3.hd 1106_line3.ini 1106_line4.dt1
 1106_line4.gp2 1106_line4.hd 1106_line4.ini 1106_line4.int 1106_line5.dt1
 1106_line5.gp2 1106_line5.hd 1106_line5.ini 1106_line5.int 1106_line6.dt1
 1106_line6.gp2 1106_line6.hd 1106_line6.ini 1106_line6.int
 1106_line7_cmp.dt1 1106_line7_cmp.gp2 1106_line7_cmp.hd 1106_line7_cmp.ini
 1119_line1.dt1 1119_line1.gp2 1119_line1.hd 1119_line1.ini 1119_line1.int
 1119_line2.dt1 1119_line2.gp2 1119_line2.hd 1119_line2.ini 1119_line4.dt1
 1119_line4.gp2 1119_line4.hd 1119_line4.ini 1119_line4.int .hd, .ini, .int
 **Description:** header files .dt1 **Description:** CMP data files .gp2
 **Description:** GPS files ## Code/software The files were processed using
 ReflexW:
 [https://www.sandmeier-geo.de/reflexw.html](https://www.sandmeier-geo.de/reflexw.html) There are a number of free/open source software that can be used to view and process GPR data, including: [https://github.com/NSGeophysics/GPRPy](https://github.com/NSGeophysics/GPRPy) [https://emanuelhuber.github.io/RGPR/](https://emanuelhuber.github.io/RGPR/) [https://www.gpr-archaeology.com/software/](https://www.gpr-archaeology.com/software/)