Note

Click here to download the full example code

5.1.1.3. ASCII2NC:Basic Use Case

This use case will run the MET ASCII2NC tool to convert point observation data in ASCII text format to NetCDF format.

Scientific Objective

None. Simply converting file formats so point observations can be read by the MET tools.

Datasets

Observations: Precipitation accumulation observations in ASCII text files
Location: All of the input data required for this use case can be found in the met_test sample data tarball. Click here to the METplus releases page and download sample data for the appropriate release: https://github.com/NCAR/METplus/releases
This tarball should be unpacked into the directory that you will set the value of INPUT_BASE. See ‘Running METplus’ section for more information.
Data Source: Unknown

METplus Components

This use case utilizes the METplus ASCII2NC wrapper to generate a command to run the MET tool ASCII2NC if all required files are found.

METplus Workflow

ASCII2NC is the only tool called in this example. It processes the following run time:

Valid: 2010-01-01_12Z

METplus Configuration

METplus first loads all of the configuration files found in parm/metplus_config, then it loads any configuration files passed to METplus via the command line with the -c option, i.e. -c parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC.conf

[config]
## Configuration-related settings such as the process list, begin and end times, etc.

# List of applications to run - only ASCII2NC for this case
PROCESS_LIST = ASCII2NC

# time looping - options are INIT, VALID, RETRO, and REALTIME
# If set to INIT or RETRO:
#   INIT_TIME_FMT, INIT_BEG, INIT_END, and INIT_INCREMENT must also be set
# If set to VALID or REALTIME:
#   VALID_TIME_FMT, VALID_BEG, VALID_END, and VALID_INCREMENT must also be set
LOOP_BY = VALID

# Format of VALID_BEG and VALID_END using % items
# %Y = 4 digit year, %m = 2 digit month, %d = 2 digit day, etc.
# see www.strftime.org for more information
# %Y%m%d%H expands to YYYYMMDDHH
VALID_TIME_FMT = %Y%m%d%H

# Start time for METplus run - must match VALID_TIME_FMT
VALID_BEG = 2010010112

# End time for METplus run - must match VALID_TIME_FMT
VALID_END = 2010010112

# Increment between METplus runs (in seconds if no units are specified)
#  Must be >= 60 seconds
VALID_INCREMENT = 1M

# List of forecast leads to process for each run time (init or valid)
# If unset, defaults to 0 (don't loop through forecast leads
LEAD_SEQ = 0

# Order of loops to process data - Options are times, processes
# Not relevant if only one item is in the PROCESS_LIST
# times = run all wrappers in the PROCESS_LIST for a single run time, then
#   increment the run time and run all wrappers again until all times have
#   been evaluated.
# processes = run the first wrapper in the PROCESS_LIST for all times
#   specified, then repeat for the next item in the PROCESS_LIST until all
#   wrappers have been run
LOOP_ORDER = times

# Verbosity of MET output - overrides LOG_VERBOSITY for ASCII2NC only
#LOG_ASCII2NC_VERBOSITY = 1

# MET Configuration file for ASCII2NC
# References CONFIG_DIR from the [dir] section
ASCII2NC_CONFIG_FILE = {CONFIG_DIR}/Ascii2NcConfig_wrapped

# Time relative to valid time (in seconds if no units are specified) to allow files to be considered
#  valid. Set both BEGIN and END to 0 to require the exact time in the filename
#  Not used in this example.
ASCII2NC_FILE_WINDOW_BEGIN = 0
ASCII2NC_FILE_WINDOW_END = 0

# Time relative to each input file's valid time (in seconds if no units are specified) for data within the file to be
# considered valid.
ASCII2NC_WINDOW_BEGIN = 0
ASCII2NC_WINDOW_END = 0

# Value to pass with the -format argument to ascii2nc. See MET User's Guide for more information
ASCII2NC_INPUT_FORMAT =

# Value to pass with the -mask_grid argument to ascii2nc. See MET User's Guide for more information
ASCII2NC_MASK_GRID =

# Value to pass with the -mask_poly argument to ascii2nc. See MET User's Guide for more information
ASCII2NC_MASK_POLY =

# Value to pass with the -mask_sid argument to ascii2nc. See MET User's Guide for more information
ASCII2NC_MASK_SID =

# For defining the time periods for summarization
# False for no time summary, True otherwise
# The rest of the ASCII2NC_TIME_SUMMARY variables are ignored if set to False
# See the MET User's Guide section regarding ASCII2NC time summary options for more information.
ASCII2NC_TIME_SUMMARY_FLAG = False
ASCII2NC_TIME_SUMMARY_RAW_DATA = False
ASCII2NC_TIME_SUMMARY_BEG = 000000
ASCII2NC_TIME_SUMMARY_END = 235959
ASCII2NC_TIME_SUMMARY_STEP = 300
ASCII2NC_TIME_SUMMARY_WIDTH = 600
ASCII2NC_TIME_SUMMARY_GRIB_CODES = 11, 204, 211
ASCII2NC_TIME_SUMMARY_VAR_NAMES =
ASCII2NC_TIME_SUMMARY_TYPES = min, max, range, mean, stdev, median, p80
ASCII2NC_TIME_SUMMARY_VALID_FREQ = 0
ASCII2NC_TIME_SUMMARY_VALID_THRESH = 0.0


# End of [config] section and start of [dir] section
[dir]
# location of configuration files used by MET applications
CONFIG_DIR={PARM_BASE}/met_config

# Input/Output directories can be left empty if the corresponding template contains the full path to the files
ASCII2NC_INPUT_DIR = 
ASCII2NC_OUTPUT_DIR =

# End of [dir] section and start of [filename_templates] section
[filename_templates]

# Template to look for input to ASCII2NC relative to ASCII2NC_INPUT_DIR
ASCII2NC_INPUT_TEMPLATE = {INPUT_BASE}/met_test/data/sample_obs/ascii/precip24_{valid?fmt=%Y%m%d%H}.ascii

# Template to use to write output from ASCII2NC
ASCII2NC_OUTPUT_TEMPLATE = {OUTPUT_BASE}/ascii2nc/precip24_{valid?fmt=%Y%m%d%H}.nc

MET Configuration

METplus sets environment variables based on the values in the METplus configuration file. These variables are referenced in the MET configuration file. YOU SHOULD NOT SET ANY OF THESE ENVIRONMENT VARIABLES YOURSELF! THEY WILL BE OVERWRITTEN BY METPLUS WHEN IT CALLS THE MET TOOLS! If there is a setting in the MET configuration file that is not controlled by an environment variable, you can add additional environment variables to be set only within the METplus environment using the [user_env_vars] section of the METplus configuration files. See the ‘User Defined Config’ section on the ‘System Configuration’ page of the METplus User’s Guide for more information.

////////////////////////////////////////////////////////////////////////////////
//
// Default ascii2nc configuration file
//
////////////////////////////////////////////////////////////////////////////////

//
// The parameters listed below are used to summarize the ASCII data read in
//

//
// Time periods for the summarization
// obs_var (string array) is added and works like grib_code (int array)
// when the obs name is given instead of grib_code
//

time_summary = {
  flag = ${TIME_SUMMARY_FLAG};
  raw_data = ${TIME_SUMMARY_RAW_DATA};
  beg = ${TIME_SUMMARY_BEG};
  end = ${TIME_SUMMARY_END};
  step = ${TIME_SUMMARY_STEP};
  width = ${TIME_SUMMARY_WIDTH};
  grib_code = [ ${TIME_SUMMARY_GRIB_CODES} ];
  obs_var   = [ ${TIME_SUMMARY_VAR_NAMES} ];
  type = [ ${TIME_SUMMARY_TYPES} ];
  vld_freq = ${TIME_SUMMARY_VALID_FREQ};
  vld_thresh = ${TIME_SUMMARY_VALID_THRESH};
}

//
// Mapping of input little_r report types to output message types
//
message_type_map = [
   { key = "FM-12 SYNOP";  val = "ADPSFC"; },
   { key = "FM-13 SHIP";   val = "SFCSHP"; },
   { key = "FM-15 METAR";  val = "ADPSFC"; },
   { key = "FM-18 BUOY";   val = "SFCSHP"; },
   { key = "FM-281 QSCAT"; val = "ASCATW"; },
   { key = "FM-32 PILOT";  val = "ADPUPA"; },
   { key = "FM-35 TEMP";   val = "ADPUPA"; },
   { key = "FM-88 SATOB";  val = "SATWND"; },
   { key = "FM-97 ACARS";  val = "AIRCFT"; }
];

//
// Indicate a version number for the contents of this configuration file.
// The value should generally not be modified.
//
version = "V9.0";

Note the following variables are referenced in the MET configuration file. Please see the MET User’s Guide section regarding ASCII2NC time summary options for more information.

  • ${TIME_SUMMARY_FLAG} - True/False option to compute time summary statistics. Corresponds to ASCII2NC_TIME_SUMMARY_FLAG in the METplus configuration file.

  • ${TIME_SUMMARY_RAW_DATA} - Corresponds to ASCII2NC_TIME_SUMMARY_RAW_DATA in the METplus configuration file.

  • ${TIME_SUMMARY_BEG} - Corresponds to ASCII2NC_TIME_SUMMARY_BEG in the METplus configuration file.

  • ${TIME_SUMMARY_END} - Corresponds to ASCII2NC_TIME_SUMMARY_END in the METplus configuration file.

  • ${TIME_SUMMARY_STEP} - Corresponds to ASCII2NC_TIME_SUMMARY_STEP in the METplus configuration file.

  • ${TIME_SUMMARY_WIDTH} - Corresponds to ASCII2NC_TIME_SUMMARY_WIDTH in the METplus configuration file.

  • ${TIME_SUMMARY_GRIB_CODES} - Corresponds to ASCII2NC_TIME_SUMMARY_GRIB_CODES in the METplus configuration file.

  • ${TIME_SUMMARY_VAR_NAMES} - Corresponds to ASCII2NC_TIME_SUMMARY_VAR_NAMES in the METplus configuration file.

  • ${TIME_SUMMARY_TYPES} - Corresponds to ASCII2NC_TIME_SUMMARY_TYPES in the METplus configuration file.

  • ${TIME_SUMMARY_VALID_FREQ} - Corresponds to ASCII2NC_TIME_SUMMARY_VALID_FREQ in the METplus configuration file.

  • ${TIME_SUMMARY_VALID_THRESH} - Corresponds to ASCII2NC_TIME_SUMMARY_VALID_THRESH in the METplus configuration file.

Running METplus

This use case can be run two ways:

  1. Passing in ASCII2NC.conf then a user-specific system configuration file:

    master_metplus.py -c /path/to/METplus/parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC.conf -c /path/to/user_system.conf

  2. Modifying the configurations in parm/metplus_config, then passing in ASCII2NC.conf:

    master_metplus.py -c /path/to/METplus/parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC.conf

The former method is recommended. Whether you add them to a user-specific configuration file or modify the metplus_config files, the following variables must be set correctly:

  • INPUT_BASE - Path to directory where sample data tarballs are unpacked (See Datasets section to obtain tarballs). This is not required to run METplus, but it is required to run the examples in parm/use_cases

  • OUTPUT_BASE - Path where METplus output will be written. This must be in a location where you have write permissions

  • MET_INSTALL_DIR - Path to location where MET is installed locally

Example User Configuration File:

[dir]
INPUT_BASE = /path/to/sample/input/data
OUTPUT_BASE = /path/to/output/dir
MET_INSTALL_DIR = /path/to/met-X.Y

NOTE: All of these items must be found under the [dir] section.

Expected Output

A successful run will output the following both to the screen and to the logfile:

INFO: METplus has successfully finished running.

Refer to the value set for OUTPUT_BASE to find where the output data was generated. Output for this use case will be found in ascii2nc (relative to OUTPUT_BASE) and will contain the following file:

  • precip24_2010010112.nc

Keywords

Note

ASCII2NCToolUseCase

sphinx_gallery_thumbnail_path = ‘_static/met_tool_wrapper-ASCII2NC.png’

Total running time of the script: ( 0 minutes 0.000 seconds)

Gallery generated by Sphinx-Gallery