Convert: Convert raw Gem data to segy

In gemlog: File Conversion for 'Gem Infrasound Logger'

Description

Convert takes a directory of raw Gem data files and converts them to PASSCAL segy files, including interpolating time with GPS strings and converting from counts to pressure units.

Usage

Convert(rawpath = ".", convertedpath = "converted", metadatapath = "metadata", 
metadatafile = NA, gpspath = "gps", gpsfile = NA, t1 = -Inf, t2 = Inf, nums = NaN, 
SN = character(), bitweight = NaN, units = 'Pa', time_adjustment = 0, blockdays = 1)

Arguments

rawpath	Directory containing raw data to be converted.
convertedpath	Directory (to be created, if necessary) where output segy files will be saved.
metadatapath	Directory (to be created, if necessary) where output metadata file will be saved.
metadatafile	Filename for output metadata. If set, overrides metadatapath. If unset, Convert creates the next logical filename in metadatapath.
gpspath	Directory (to be created, if necessary) where output gps file will be saved.
gpsfile	Filename for output gps data. If set, overrides gpspath. If unset, Convert creates the next logical filename in gpspath.
t1	Time at which conversion should start (class POSIXct).
t2	Time at which conversion should end (class POSIXct).
nums	File numbers to convert.
SN	Serial number of Gem data files to convert (to be safe, when data from multiple Gems could be mixed).
bitweight	Conversion factor between counts and output units (e.g., Pa per count). Leave as NaN to use default value (for logger version, configuration, and 'units').
units	Units for output: can be 'Pa', 'V', or 'counts'. Only used when bitweight is left unset and default bitweight is calculated.
time_adjustment	Offset to add to output times (usually unnecessary, sometimes +/- 1 s).
blockdays	Amount of data (measured in days) to process at a time. This can be decreased to 0.5 or 0.25 in case of memory problems.

Details

This is the usual function to use when converting data to segy files. To read data directly into R, use ReadGem.

Value

None; writes files only.

Note

A good directory structure might be something like

projectname

—-raw

——–010: Directory containing data from Gem SN 010 (e.g.)

——–011: Directory containing data from Gem SN 011 (e.g.)

—-converted

——–segy files

—-gps

——–010gps_000.txt: GPS file for Gem 010

——–011gps_000.txt: GPS file for Gem 011

—-metadata

——–010metadata_000.txt: Metadata file for Gem 010

——–011metadata_000.txt: Metadata file for Gem 011

—-projectname_notes.txt

Author(s)

Jake Anderson

See Also

ReadGem

Examples

## Not run: 
# define bitweight for 0.5 inch sensor with Rg = 2.2k
sensitivity = 22.014e-6 # 22.014 uV/Pa
Rg = 2.2 # gain-setting resistor value in kilo-ohms
gain = 1 + 49.4/2.2 # amplifier gain
A2D = 0.256/2^15 # volts per count in analog-digital converter
bitweight = A2D / (gain * sensitivity) # conversion from counts to Pa (Pa/count)

# convert files from two Gems (SNs 000 and 001)
Convert('raw/000', bitweight = bitweight)
Convert('raw/001', bitweight = bitweight)

## End(Not run)

gemlog documentation built on July 2, 2020, 2:30 a.m.