Entity_Type:
Entity_Type_Label: 2015-611-FA_GPR_ASCII_Raw_Data.zip
Entity_Type_Definition:
File containing each raw, unprocessed GPR profile in ASCII format. Many XYZ processing programs will not accept column header labels; therefore, they were not placed in the file. Column 1= Horizontal distance (meters), Column 2= elevation, Column 3= two-way travel time, Column 4= Amplitude.
Entity_Type_Definition_Source: USGS
Attribute:
Attribute_Label: Horizontal distance
Attribute_Definition:
This column indicates the location in meters from the start (0) to the end of the GPR profile, this column can be used to locate the position of reflections. The distance data were collected using the distance measuring wheel.
Attribute_Definition_Source: Reflexw
Attribute_Domain_Values:
Unrepresentable_Domain:
Values start with 0 (the beginning of the profile) and end with the total distance covered by the profile, units are in meters.
Attribute:
Attribute_Label: Elevation
Attribute_Definition:
All values in this column are 0 as a result of elevation data being contained in the GGA string and not recorded in the ASCII file.
Attribute_Definition_Source: Reflexw
Attribute_Domain_Values:
Unrepresentable_Domain: Values are all zero since elevation data have not been applied.
Attribute:
Attribute_Label: Two-way travel time
Attribute_Definition:
This column records the two-way travel time, in nanoseconds, that it takes to reach a reflection from the source.
Attribute_Definition_Source: Reflexw
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 170
Attribute:
Attribute_Label: Amplitude
Attribute_Definition: Amplitude of the reflection, in Megahertz
Attribute_Definition_Source: Reflexw
Attribute_Domain_Values:
Unrepresentable_Domain:
Data represent the amplitude of the reflection, which can vary widely, and values can be either negative or positive.
Entity_Type:
Entity_Type_Label: 2015-611-FA-GGA_Strings.zip
Entity_Type_Definition:
File containing the processed navigation data for the GPR profiles. Data do not contain column labels Column 1= Message ID $GPGGA, Column 2= UTC of position fix, Column 3= Latitude, Column 4= Direction of latitude: N, Column 5= Longitude, Column 6= Direction of longitude: W, Column 7= GPS Quality indicator:0: Fix not valid 1: GPS fix 2: Differential GPS fix, OmniSTAR VBS 4: Real-Time Kinematic, fixed integers 5: Real-Time Kinematic, float integers, OmniSTAR XP/HP or Location RTK, Column 8= Number of Space Vehicles (SVs) in use, range from 00 through to 24+, Column 9= Horizontal Dilution of Precision (HDOP), Column 10= Orthometric height (MSL reference), Column 11= M: unit of measure for orthometric height is meters, Column 12= Geoid Separation, Geoid 13= M: geoid separation measured in meters, Column 14= Age of differential GPS data record, Type 1 or Type 9. Null field when DGPS is not used. Column 15= Reference station ID, range 0000-4095. A null field when any reference station ID is selected, and no corrections are received. Column 16= The checksum data always begins with *.
Entity_Type_Definition_Source: GrafNav
Attribute:
Attribute_Label: Message ID $GPGGA
Attribute_Definition: The type of file, indicates it is a GGA string.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Attribute is a file format identification.
Attribute:
Attribute_Label: UTC of position fix
Attribute_Definition: GPS time in seconds.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Value is GPS time, increases by 1 every second.
Attribute:
Attribute_Label: Latitude
Attribute_Definition:
The latitude of the XYZ point, latitude is projected in UTM 18N.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Values are degrees of latitude, spatial data.
Attribute:
Attribute_Label: Direction of latitude:
Attribute_Definition: Direction of latitude is in the Northern (N) Hemisphere.
Attribute_Definition_Source: GravNav
Attribute_Domain_Values:
Unrepresentable_Domain:
The attribute indicates that the degree of latitude is in the Northern Hemisphere.
Attribute:
Attribute_Label: Longitude
Attribute_Definition: The longitude of the XYZ data point.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Values are the degree of longitude, spatial data.
Attribute:
Attribute_Label: Direction of longitude:
Attribute_Definition: Direction of longitude is in the Western (W) Hemisphere.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain:
The attribute indicates that the degree of longitude is in the Western Hemisphere.
Attribute:
Attribute_Label:
GPS Quality indicator:
0: Fix not valid
1: GPS fix
2: Differential GPS fix, OmniSTAR VBS
4: Real-Time Kinematic, fixed integers
5: Real-Time Kinematic, float integers, OmniSTAR XP/HP or Location RTK
Attribute_Definition: Defines the type and quality of the DGPS data.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 5
Attribute:
Attribute_Label: Number of SVs in use, range from 00 through to 24+
Attribute_Definition:
Number of satellites utilized by the program to process the data.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 00
Range_Domain_Maximum: 24
Attribute:
Attribute_Label: HDOP
Attribute_Definition:
Horizontal Dilution of Precision (HDOP) expresses the effect of satellite positions on the precision of the reported positions. < 1 Ideal, 1-2 Excellent, 2-5 good, 5-10 moderate, 10-20 fair, >20 poor.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 20
Attribute:
Attribute_Label: Orthometric height (MSL reference)
Attribute_Definition:
Height of the XYZ position in reference to NAVD88 using GEIOD12A.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Elevation above the GEIOD12A in meters, spatial data.
Attribute:
Attribute_Label: M: unit of measure for orthometric height is meters
Attribute_Definition: The orthometric height is reported in meters.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Indicates data are reported in meters.
Attribute:
Attribute_Label: Geoid separation
Attribute_Definition:
Separation between GEIOD12A and the reference ellipsoid NAVD88 in meters.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain:
Separation between GEIOD12A and the reference ellipsoid NAVD88 in meters.
Attribute:
Attribute_Label: M: geoid separation measured in meters
Attribute_Definition:
Defines the separation between GEIOD12A and the reference ellipsoid NAVD88 measured in meters (m).
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Indicates data are reported in meters.
Attribute:
Attribute_Label:
Age of differential GPS data record, Type 1 or Type 9. Null field when DGPS is not used.
Attribute_Definition: The corrected DGPS time
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 9
Attribute:
Attribute_Label:
Reference station ID, range 0000-4095. A zerois used when any reference station ID is selected and no corrections are received.
Attribute_Definition:
Refers to the reference station used to process the DGPS data presented in this dataset.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4095
Attribute:
Attribute_Label: The checksum data, always begins with *
Attribute_Definition: The name of the checksum data used to detect errors.
Attribute_Definition_Source: GrafNav
Attribute_Domain_Values:
Unrepresentable_Domain: Numbers increase sequentially by 1.
Entity_Type:
Entity_Type_Label: 2015-611-FA_GPR profile parameters.xlsx
Entity_Type_Definition:
Microsoft Excel table listing the parameters assigned to each GPR profile during collection in the field.
Entity_Type_Definition_Source: USGS
Attribute:
Attribute_Label: Line
Attribute_Definition: Lists the profile name.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 195
Range_Domain_Maximum: 235
Attribute:
Attribute_Label: scans/second
Attribute_Definition:
The horizontal sampling rate if the system is in continuous data collection mode.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Lines 195-221 were collected at a rate of 64 scans/second, lines 222-235 were collected at 32 scans/second.
Attribute:
Attribute_Label: scans/unit(m)
Attribute_Definition:
Scan/unit(m) refers to the number of scans per horizontal meter.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Lines 195-221 were collected at a rate of 20 scans/unit(m) lines 222-235 were collected at 28 scans/unit(m).
Attribute:
Attribute_Label: samples/scan
Attribute_Definition: Sample/scan set the number of data samples in a vertical scan.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Lines 195-221 were collected at a rate of 1024 samples/scan, lines 222-235 were collected at 2048 samples/scan.
Attribute:
Attribute_Label: bits/sample
Attribute_Definition: The bits/sample determine the dynamic range of the data.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain: All lines were collected at 16 bits/sample.
Attribute:
Attribute_Label: dielectric constant
Attribute_Definition:
This column lists the assumed dielectric constant assigned to the GPR during collection of data, this determines the vertical scale, in meters, during data collection.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain:
All lines were collected with a display assuming a dielectric constant of 15.
Attribute:
Attribute_Label: range (ns)
Attribute_Definition:
range (ns) is the maximum two-way travel time in nanoseconds that is viewed during data collection.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Lines 195-220 were collected with a range of 150, lines 221-235 were collected with a range of 170.
Attribute:
Attribute_Label: MHz
Attribute_Definition:
The MHz of the antennae used to collect the data, a 400 MHz antennae was used.
Attribute_Definition_Source: Defined by antennae used.
Attribute_Domain_Values:
Unrepresentable_Domain: All lines were collected with a 400 MHz antennae.
Entity_and_Attribute_Overview:
The entity and attribute information provided here describes the tabular data associated with the dataset. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset.
Entity_and_Attribute_Detail_Citation:
The entity and attribute information was generated by the individual or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.