Preparing Data: the Data Translaters

• Interactive mode
• Deleting sweep files
• Environment variables
• Mandatory Environment Variables
  • INPUT_FORMAT
  • SOURCE_DEV
  • DORADE_DIR
  • OUTPUT_FLAGS
• DORADE_DATA output.
• Universal Format or UF_DATA output.
• CAPPI_DATA output.
• [More links to be added]

The input formats that can be handled by the translater are DORADE_FORMAT, WSR_88D_FORMAT, UF_FORMAT, NCAR FOF_FORMAT, TDWR_FORMAT and HRD_FORMAT. References to P3 and HRD are considered synonymous in this context. Additionally, several in-house formats (e.g., ELDORA_FORMAT and PIRAQ_FORMAT) may be used as input to SOLO.

The translaters separate the HRD tail radar data as if it were two radars, and data are designated as fore "TF" or aft "TA" depending on the tilt angle.

Translaters are driven with environment variables usually set up in a script file. This file can be named by the user and must be executable. To make a file executable the protection must be changed with the chmod command.For example:

	chmod 755 script_file_name

This will give the owner, group and world executable privileges while providing only the owner with read and write abilities. A typical script might look like:

# Batch Mode script to produce dorade sweep files from WSR_88D radar tapes
#

	setenv BATCH_MODE
	setenv INPUT_FORMAT "WSR_88D_FORMAT"
	setenv OUTPUT_FLAGS "SWEEP_FILES"
	setenv DORADE_DIR /scr/mead/nexrad
	setenv PROJECT_NAME "NEXRAD"
	setenv RADAR_NAME "KFTG"
	setenv COMPRESSION_SCHEME "HRD_COMPRESSION"
	setenv TIME_LIMITS "08/03/94:21:30 < 08/03/94:23:30"
	setenv FIXED_ANGLES "0.0 < 2.0 4.0 < 5.0"
	setenv SOURCE_DEV /dev/nexa
	nice +11 /local/bin/xltrs  # be sure to specify the proper 
				   # path to the translater
#

Typing this executable script name at the prompt should create compressed sweep files and a catalog of scans with elevation angles between 0 and 2 degrees and 4 and 5 degrees in the "/scr/mead/nexrad" directory for the time period indicated on August 3, 1994 from the data tape in the source device /dev/nexa. The last line of the script invokes the actual translater program. Be sure that the full pathname of the executable is specified, or that your environment variable "PATH" is set to include the proper version of the executable. When substituting your source device, be sure to specify a device name which is Berkeley compatible. On Suns running Solaris, this might be /dev/rmt/0bn. If you are not sure which device to use, check with your system administrator.

Interactive mode is also available. The script for the interactive mode can be exactly the same as the batch mode but the line "setenv BATCH_MODE" must be removed. A typical interactive mode script might look like:

	# Interactive mode script to produce dorade sweep files from WSR_88D
	# radar tapes
	#
	setenv INPUT_FORMAT "WSR_88D_FORMAT"
	setenv OUTPUT_FLAGS "SWEEP_FILES"
	setenv DORADE_DIR /scr/mead/nexrad
	setenv PROJECT_NAME "NEXRAD"
	setenv RADAR_NAME "KFTG"
	setenv COMPRESSION_SCHEME "HRD_COMPRESSION"
	setenv SOURCE_DEV /dev/nexa
	nice +11 /local/bin/xltrs
	#

To invoke the translater, type the script filename at the prompt. The following menu should appear:

 
	-1 = exit program (-2 exits from some other prompts)
         0 = continue
	 1 = repeat last run

You are now in the interactive version of the translater. Typing a 0 and hitting <return>, or just hitting <return> should bring up the next menu which looks like the following:

	-2 = Exit
	-1 = Begin processing
	 0 = Skip rays
	 1 = Inventory
	 2 = Skip files
	 3 = Rewind
	 4 = 16-bit integers
	 5 = hex display
	 6 = dump as characters
	 7 = Skip records
	 8 = Forward time skip
	 9 = Fixed angle search
	10 = Set Input Limits
	11 = Display headers
	12 = Display data
	13 = Time correction
	14 = Sweep time tolerance
	15 = Rotation angle tolerance
	Option =

This version of the translater gives you more flexibility to move around in and familiarize yourself with what the data contain, whereas batch mode is more useful if you are familiar with the data and with exactly what times and angles you want to use. The following is a brief description of the options in the above menu.

 -1 =	Begin processing the data by loading in the number of
	scans specified in option 10 of the menu or by cataloging
	the data, whichever was specified in the script. After
	the requested number of scans have been processed, the program
	looks for an end-of-file mark and then stops. If the number of
	scans is not specified before you begin processing, the
	program will continue until reaching the end-of-tape,
	unless a time limit was specified in the script.

 0 = 	Skip through the data ray by ray. May not go back as far as
	you want because only a certain number of records are kept
	around. This is mainly for formats where there may be several
	rays per physical record like NEXRAD, where you may want to back
	up a few rays.

  1 = 	Inventory the data, beam by beam (display azimuth, elevation, 
	etc., for each beam).

  2 = 	Skip forward and backward through the data by files.

  3 = 	Rewind the tape to the begining.

  4 = 	Display the current record as 16-bit integers.

  5 = 	Display the current record as hexidecimal (base 16). Makes
	it easier to see bit patterns.

  6 = 	Interpret a byte in the data as a character if it can.

  7 =   Move around in the data by records. Negative numbers can
	be used in order to skip back.

  8 = 	Skip ahead in time either by giving a specific time, or by
	specifying the number of hours, minutes, or seconds to skip.

  9 = 	Search forward for a specified fixed angle.   Specify the 
	nominal angle, and a tolerance.  For example, typing 2.0 0.5
	would set the translater searching for a fixed angle between,
	and including, 1.5 and 2.5 degrees. You only need to give the 
	range number if you want to change its value other wise the 
	last one used will be remembered.  The default is a 0.2 degree 
	range.

 10 = 	Brings up the following sub-menu, which allows you to set
	different limits for the control of sweep file output.

	 0 = Cease - Go back to previous menu
	 1 = Enter time span - Specify time limits in which data is processed
	 2 = Enter scan count - Set the number of sweep files written to disk
	 3 = Enter volume count - Specifies the number of volumes to process
	 4 = Enter ray count - Number of rays translater will process
	 5 = Enter fixed angle limits - Used if you only want certain angles processed
	 6 = Enter PRF limits - Will only process scans with prf's within this limit
	 7 = Enter num lines in browser display - allows you to customize
	     the number of lines you want the translater to display in
	     your window

 11 = 	Give a listing of the header information.

 12 = 	Show the actual values for each field contained in the
	data.

When you are in the options that display headers or data (usually items after item 10), typing a positive number, n, causes a redisplay beginning n lines further than the first line in the current display; typing a negative number causes a redisplay beginning n lines previous to the first line of the display. Typing a number that is greater than the number of lines in the listing causes the final lines in the listing to be displayed, and typing a large negative number causes the first lines in the listing to be displayed. To exit the display, type a non-numeric character followed by a return.

After some data (at least one full sweep) have been loaded to disk, you are ready to begin using SOLO. When using the interactive version of the translater to search through data, you may want to keep it going in one window and to open SOLO in another. SOLO is able to see new data as they are read to disk without exiting and re-entering the program. It may be necessary to "pop up" the sweep widget and display the list of sweeps to display the newer sweeps, since SOLO does not rescan the directory for every sweep it plots.

You might also find it helpful to use the GNU emacs directory editor (dired) for selectively deleting sweep files. On many systems you type emacs preferably from the directory where you want to do the deletion. Then type <CTRL>x and then a "d" and you will be prompted for the directory name. If you are already in the directory you can just type <return>. Once you have a list of files you can move around with the arrows and type a "d" at each file you wish to delete. When you want to delete the files you have flagged, type an "x" and you will get a list of the files emacs is going to delete. Type "yes" to confirm.

• DORADE_DATA output.
• Universal Format or UF_DATA output.
• CAPPI_DATA output.

A note on environment variables: the user should be aware that on some systems in certain shells (most notably hpux and the csh environment), variables must have an argument. So a variable such as BATCH_MODE needs to be set with the following command:

		setenv BATCH_MODE ""

Since tokens in strings are expected to be seperated by spaces or tabs, all ordered triplets in environment variables such as "800 < 2000" in

		setenv PRF_LIMITS "800 < 2000"

Quotes are needed whenever the value of a variable includes blanks or unusual characters. Omission of necessary quotes will cause unexpected results!

A list of currently defined environmental variables follows (in the list, the environment variable is provided first, followed by an example of its usage, followed by a description of usage):

AC_NETCDF_FILE

setenv AC_NETCDF_FILES "/dt/oye/RF05.cdf"

Specifies a merge of RAF netCDF airborne data with the radar platform descriptor parameters and also specifies what file is to be used. Currently this should be a "low-rate" tape. The default set of RAF netCDF field names used is: "HGME PITCH ROLL THDG VEWC VNSC VSPD LATC LONC PALT UIC VIC WIC".

AC_NETCDF_ALIASES

setenv AC_NETCDF_ALIASES "LATC < GLAT LONC < GLON"

Allows substitution for the default fields of the RAF netCDF aircraft data tape which are used to revise various platform descriptor parameters. Fields not referenced will use the default name. If you wish not to replace some of the fields then you can indicate this with the entry ROLL < NOT and the roll will not be replaced. If you wish to substitude only one or two fields you can say "ONLY HGME < HGME LONC < LON" for example.

AC_TIME_CORRECTION

setenv AC_TIME_CORRECTION -172800.000

Allows for adjusting the RAF netCDF time stamp the units are plus or minus seconds.

AFT_ANGLE_LIMITS

setenv AFT_ANGLE_LIMITS "-25. < -5."

This applies primarily to HRD data and specifies the limits of the elevation angles for the data assigned to be the aft radar.

ALTITUDE_LIMITS

setenv ALTITUDE_LIMITS "-2.5 < 22.5"

Specifies the altitude limits for data in km. msl. All data below the lower limit and above the upper limit will be assigned a bad data flag and "compressed out" of the dataset, if you are using compression. The program uses the elevation of the beam and the altitude of the radar to cutoff the data above and below the two limits. For aircraft data, this can cut UF files in half and for DORADE, the average sweep compresses to one-third its non-compressed size.

AZ_SECTORS

setenv AZ_SECTORS "22.0 < 33.0 66.0 < 77.0"

Ignores data outside the two sets of azimuth limits.

BEAM_COUNT

setenv BEAM_COUNT 22

The beam count is just a way of stopping the program if you are just testing things.

CAPPI_LEVELS

setenv CAPPI_LEVELS 6000

Produces a cappi at the level indicated which is in meters above mean sea level.

CAPPI_LATITUDES

setenv CAPPI_LATITUDES "32.8"

Normally the cappi algorithm selects the origin of the grid for the cappi based on the heading and the location of the aircraft but if you wish to fix the origin for each time interval, you can enter one latitude for each time interval using this environment variable. If there are not enough locations for the corresponding number of time limits the algorithm reverts back to the automatic calculation of the cappi origin.

CAPPI_LONGITUDES

setenv CAPPI_LONGITUDES "-100.5"

See the explanation of CAPPI_LATITUDES above.

CAPPI_RADAR

setenv CAPPI_RADAR "TF"

Selects the radar whose data is used to produce the cappi.

CAPPI_REFL

setenv CAPPI_REFL "DBZ"

Selects which field is used for the reflectivity field.

CAPPI_TIMES

setenv CAPPI_TIMES "04/19/95:20:40:41 < 20:49:40"

Produces a cappi at the time(s) requested. There can be more than on set of times just as with TIME_LIMITS. Be sure to reinclude the date when the times cross midnight.

CAPPI_VEL

setenv CAPPI_VEL "VU"

Selects which field is used for the velocity field.

COMPRESSION_SCHEME

setenv COMPRESSION_SCHEME "HRD_COMPRESSION"

Sweep files will probably be one third their normal size when compressed if they contain aircraft data and appropriate ALTITUDE_LIMITS are specified. Files are often less than one-third their normal uncompressed size, especially for NEXRAD data.

This is the only compression scheme we employ at present. The algorithm compresses on the basis of 16-bit boundaries. It is run-length-encoded (RLE), and an RLE word indicates either the number of deleted (bad flagged) 16-bit words or the number of 16-bit words to follow. The compression is terminated by a 1 in an RLE word.

DERIVED_FIELDS

setenv DERIVED_FIELDS "VE < VG VE < VU"

There are several specially derived fields available as part of the translation process. The first two are for use with aircraft (P3 and ELDORA) data.

"VE < VG VE < VU"

The left hand side of the ordered pair indicates the source field id. The right hand side indicates the destination field id and a specific process for deriving this field. VG implies just to remove the aircraft motion from the velocity and force the result velocity Nyquist interval to be centered on 0 while VU implies to remove any aircraft motion and try to unfold it.

"VR < VH"

The left hand side of the ordered pair indicates the source field id. VH implies just to remove the component of aircraft motion from the velocity. This is meant to be used for ELDORA's new unfolded velocities.

"VE < VT"

Generates a field called VT from VE that is thresholded on the NCP. The NCP field and threshold value is specifield with an environment variable A second number indicates an upper limit and the absence of this variable forces the default to 999. (in this example, everything below .333 is flagged bad):

        setenv NCP_THRESHOLD_VAL "NCP .333"  

"VE < VW"

Generates a field called VW from VE that is thresholded on the Spectral Width and is specified with an environment variable (in the following example, everything above 6.0 is flagged bad):

        setenv SW_THRESHOLD_VAL "SW 6.0" 

It is also possible to threshold on power using the environment variable:

     setenv PWR_THRESHOLD_VAL "DBZ -12.34" 

It can apply to three cases:

"VE < VP"

generates a field, VP, by bad-flagging values in VE with dBZ below -12.34

"DBZ < DP"

generates a field DP by bad-flagging values in DBZ below -12.34

"DBZ < DT"

generates a field DT by bad flagging values in DBZ ABOVE -12.34

DORADE_DEV

setenv DORADE_DEV "/scr/mead/data"

If the string "/dev" occurs anywhere in this specification, the software assumes you will be writing to tape(s); if not, the software assumes you are specifying a destination directory for DORADE data different from the DORADE_DIR directory. The name of the file will be manufactured by the Translater program. With a /dev it is possible to specify more than one device name between the double quotes. This feature along with MAX_DORADE_TAPE_SIZE allows a user to specify output to more than one physical device and the approximate amount of data in gigabytes that can be written to a physical device.

DORADE_DIR

setenv DORADE_DIR "/scr/mead/nexrad"

The destination directory for sweep files and catalog information and, unless otherwise specified, the destination directory for UF and DORADE tape image files. Older example scripts may use DD_DIR. They are synonymous. This variable is not manditory but if you are going to generate any ouput such as catalogs, sweepfiles, DORADE data, etc., you will need to set this variable.

DORADE_VOLUME_INTERVAL

setenv DORADE_VOLUME_INTERVAL 240

Volumes of aircraft data are often very long. This variable is the maximum length in seconds of a volume of data. Normally for ground based data it is desirable to respect the volume boundaries of the original data.

EL_SECTORS

setenv EL_SECTORS "0.0 < 0.9 3.3 < 4.4"

Ignores data outside the two sets of elevation limits.

FIXED_ANGLES

setenv FIXED_ANGLES "0.0 < 1.0 2.0 < 3.0"

It is possible to filter the data to a specific list of fixed angle ranges. This is the way to specify it. The "<" must be present, and the values on either side of the "<" are inclusive.

FORE_ANGLE_LIMITS

setenv FORE_ANGLE_LIMITS "5. < 25."

This applies primarily to HRD data and specifies the limits of the elevation angles for the data assigned to be the fore radar.

GECHO_MIN_GATES

setenv GECHO_MIN_GATES 33

Specifies the minimum number of cells for each ray of ground echo information to include in the ground echo file. See GECHO_DATA under OUTPUT_FLAGS.

GECHO_REFL

setenv GECHO_REFL "DZ"

Specifies the parameter name of the reflectivities used in the ground echo file.

GECHO_VEL

setenv GECHO_VEL "VE"

Specifies the parameter name of the velocities used in the ground echo file.

HRD_RANGE_DELAY

setenv HRD_RANGE_DELAY 19

Specifies that the 20th gate should be considered the first gate of data.

HRD_VOLUME_HEADER

setenv HRD_VOLUME_HEADER "/scr/mead/data/hrd9106022353.tape"

Specifies a fortran-binary file containing volume header information in case these data are missing from a particular input file.

INPUT_FORMAT

setenv INPUT_FORMAT "DORADE_FORMAT"

This is a mandatory variable. Formats with headers require that the source data device be positioned at the beginning of a file. The following formats are recognized; specific notes about the formats follow:

	DORADE_FORMAT
	WSR_88D_FORMAT
	UF_FORMAT
	ELDORA_FORMAT
	FOF_FORMAT
	SIGMET_FORMAT (not yet fully implemented)

DORADE_FORMAT

This is NCAR's "format of choice" for airbourne radar. The format was created specifically to meet the needs of the NCAR ELDORA dual-antenna, dual PRT, multi-frequency, high data rate system. Contributions to the format were solicited from NOAA's HRD and other users of radar data. The format is highly descriptive, and can be used for airbourne radar, ground-based radar, lidar systems, and other platforms collecting beam-based data.

WSR_88D_FORMAT

This format requires three tables to work properly. These tables are installed in the SOLO/lib directory, and the translater will expect to find them there unless the environment variable NEXRAD_DIR is set. The file names begin with "nexrad" and end with ".txt". One table is site information that has lat/lon/alt plus receiver bandwidth and the two pulse durations. The user must supply the four character radar id to access the proper entry in the table. These are text files that can be examined and changed independent of the software. Any reliable information concerning these parameters would be welcome. This format can also ingest user supplied information such as the lat/lon/alt of the radar, project name, and site name.

UF_FORMAT

(a.k.a. Universal Format) This optimisticlly-named format has been the designated radar data exchange format since 1981 (see The Bulletin of the American Meteorological Society, Nov 1981). However, the format does not allow sufficient description to allow easy use with current airbourne radar systems.

HRD_FORMAT

The project name must be supplied by the user.

SIGMET_FORMAT

The project name must be supplied by the user. Use of the SIGMET_FORMAT is not currently implemented.

ELDORA_FORMAT

Special format used for initial processing of ELDORA Field Format data. Generally not useful to anyone outside of the ELDORA data management group.

FOF_FORMAT

The internal format for NCAR ATD radar data; this format has been in use for radar data collected from about 1980 through 1995, and was not originally intended for exchange of radar data. Use of this format requires access to an ATD-distributed database containing radar calibratation and parameter information, grouped by date/project, and by radar. This is a compact format, and a lot of ATD ground-based radar data have been distributed in this form. This format requires the OUTPUT_FIELDS attribute to specify a list of the desired output fields.

IO_TYPE

setenv IO_TYPE "FB_IO"

This variable specifies that input files are FORTRAN-BINARY files. So far this is applicable only to the MECTEX UF radar data where the UF files do not conform completely to the FORTRAN-BINARY convention.

KEEP_ORTHOGONAL_DATA

setenv KEEP_ORTHOGONAL_DATA

This applies primarily to HRD data and specifies that tail data outside the FORE and AFT_ANGLE_LIMITS is to be preserved. The default is to discard these data. These data have the designation TA (e.g. TA43P3).

MAX_UF_CELLS

setenv MAX_UF_CELLS n

Since the number of cells/bins/gates is fixed for DORADE for a given volume, and the number of gates in UF can vary from field to field and ray to ray, this fixes the DORADE cell vector size in case the number of gates is varying in the UF data.

MAX_DORADE_TAPE_SIZE

setenv MAX_DORADE_TAPE_SIZE 4.2

Specifies the approximate maximum number of gigbytes of DORADE output that can be written to a single physical device. A switch to the next device is triggered once this limit has been exceeded during the last volume dump.

MIN_FREE_MB

setenv MIN_FREE_MB n

The program attempts to query the system for the space left on the disk partition where sweep files are written and stop itself when this boundary is crossed.

OUTPUT_FIELDS

setenv OUTPUT_FIELDS "DZ VP"

This attribute is required for FOF_FORMAT in order to specify which output fields are desired. The above example produces a dBz field thresholded on the MDS and a velocity field also thresholded on the MDS. The file ../solo/catalog/fieldlist.job contains information used to derive fields from the raw data and to decide which fields can be derived.

OUTPUT_FLAGS

setenv OUTPUT_FLAGS "DORADE_DATA UF_DATA"

This is how you specify the output for the program. The default is to produce just a catalog of the data. None of the options listed below are mutually exclusive; therefore, all the types of data listed below can be produced simultaneously. This variable is also not mandatory but you can't do too much except make a pass through the data without it.

SWEEP_FILES

Sweep files are simply the DORADE data broken up into one sweep per disk file. All of the applicable DORADE headers are included in the file plus some additional information such as a rotation angle versus ray table. The files are the basis for functioning in SOLO.

DORADE_DATA

Data in pure DORADE format are produced by accumulating a volume of sweep files on the disk and then writing them to tape or disk. It is not necessary to specify SWEEP_FILES in order to produce DORADE, but the presence of the SWEEP_FILES flag will prevent deletion of sweep files after a dorade volume has been written out if that is desirable. PRESERVE_SWEEP_FILES can also be used to preserve a file periodically. Aircraft data are often broken into smaller volumes based on the DORADE_VOLUME_INTERVAL. For disk files the software manufactures the name of the file with the form "dor.920128010203.TA-ELDR.0"; i.e., a file type prefix, the date-time, the radar name and version number. See also DORADE_DEV.

UF_DATA

The UF data are produced on a ray-by-ray basis as each ray of source data is read in. In the absence of the UF_DIRECTORY variable, UF files will be produced in DORADE_DIR. These UF files will have the form "ufd.921214163454.LF43P3.0.tape" and will be produced in fortran-binary format. Production of UF requires a SITE_NAME to be complete.

NO_CATALOG

Suppress the production of a catalog of the source data being processed. The catalog is a verbose ASCII text file.

NO_UFEOFS

Suppresses the writing of EOFs for UF output. This can be helpful if data are filtered down to one or two sweeps per volume.

CAPPI_DATA

Produces cappis at a specified level (CAPPI_LEVELS) for a given set of time intervals (CAPPI_TIMES) for a particular radar (CAPPI_RADAR). Other applicable control variables CAPPI_LATITUDES, CAPPI_LONGITUDES, CAPPI_REFL, and CAPPI_VEL.

GECHO_DATA

Produces a special-purpose file of text information that results from an attempt to calculate and record reflectivity and velocity cells around the intersection of a ray of data and the earth's surface; uses navigation information for the ray. The software to process these data and derive correction factors is not distributable at this point.

PCT_STATS

setenv PCT_STATS "ABOVE 20 DZ"

Generates statistics for the catalog that report the percentage of cells that meet the indicated criteria. In this case it's the percentage of cells in the field named DZ that are above 20. The first argument can be ABOVE, BELOW, BETWEEN, and BEYOND. BETWEEN and BEYOND require two values e.g. "BEYOND -10.0 10.0 VU".

PRESERVE_SWEEP_FILES

setenv PRESERVE_SWEEP_FILES 60

Used with DORADE_DATA to specify the period for preserving a file from each radar during DORADE output. The units are seconds and the above example preserves a sweep file from each radar approximately every 60 seconds.

PRF_LIMITS

setenv PRF_LIMITS "800 < 2000"

Specifies filtering of input data on the basis of PRF. One or more ordered pairs of upper and lower limits are accepted.

PROJECT_NAME

setenv PROJECT_NAME "TNEXRAD"

Supplies a project name that is missing for some formats.

RADAR_ALTITUDE

setenv RADAR_ALTITUDE "1.601"

Supplies the altitude for 88D data; units of km. msl.; over-rides information that may exist in the input data, or in the SOLO tables.

RADAR_LATITUDE

setenv RADAR_LATITUDE "39.531"

Supplies the latitude for 88D data, in decimal degrees; over-rides information that may exist in the input data, or in the SOLO tables.

RADAR_LONGITUDE

setenv RADAR_LONGITUDE "104.232"

Supplies the longitude for 88D data, in decimal degrees; over-rides information that may exist in the input data, or in the SOLO tables.

RADAR_NAME

setenv RADAR_NAME "KFTG"

Supplies the radar name for 88D data; mandatory for all NEXRAD data.

RENAME

setenv RENAME "FWD < TF-ELDR AFT < TA-ELDR"

Permits renaming of radars during UF input. To the left of the "<" is the old name and to the right is the replacement name.

SELECT_RADARS

setenv SELECT_RADARS "TA TF"

Allows the user to filter the input for the radars indicated. The patterns present need to uniquely match a pattern in the radar name in order for it to be selected. In the production of ELDORA and HRD tail data the translaters manufacture the radar name beginning with "TA" to indicate and aft pointing radar and "TF" to indicate a fore pointing radar. This option also works for selecting a particular radar from UF data.

SITE_NAME

setenv SITE_NAME "FRONTRNG"

Supplies a site name for UF production.

SOURCE_DEV

setenv SOURCE_DEV "/dev/nexa"

This mandatory variable specifies the name of the source device or the full path name of the source file. The presence of "/dev" in the name causes the program to assume you are reading from a physical device. In the case of DORADE the program will also try to distinguish between a pure binary file and a fortran-binary file. Fortran-binary files are different in that they have a 4-byte header and trailer around each record indicating the length of the record in bytes. On most other formats the assumption is that a disk file is in fortran-binary form.

SOURCE_TAPE_ID

setenv SOURCE_TAPE_ID "P70066"

Causes the specified string to be included in the catalog as a source tape identifier.

SWEEP_COUNT

setenv SWEEP_COUNT 11

Specifies the maximum number of sweeps that the program can generate for each radar.

SWEEP_MODES

setenv SWEEP_MODES "PPI SUR"

Causes data for the sweep modes not listed to be excluded. The default is to include all modes.

SWEEP_SKIP

setenv SWEEP_SKIP n

Causes the program to skip n sweeps for each radar after reading in a sweep for each radar; i.e., a SWEEP_SKIP of 1 means that every other sweep is used.

SWEEP_TRIP_ANGLE

setenv SWEEP_TRIP_ANGLE 0.0

This applies primarily to HRD and ELDORA data and specifies that when the antenna rotation angle passes through 0.0 degrees, this is the start of a new sweep. It is most likely that this option is not necessary, since the software will automatically sum the deltas between consecutive rotation angles and declare a new sweep when the accumulated sum of the deltas, plus the current delta, is greater than 360 degrees.

SWEEP_TRIP_DELTA

setenv SWEEP_TRIP_DELTA 45.0

This applies primarily to HRD and ELDORA data and specifies that whenever there is a gap of at least 45 degrees between consecutive rotation angles, a new sweep is declared. The default value is 100 degrees.

TIME_DEFINED_VOLUMES

setenv TIME_DEFINED_VOLUMES ""

This permits the user to define volumes based on the TIME_LIMITS variable below. i.e. each set of time limits defines a volume.

TIME_LIMITS

setenv TIME_LIMITS "12/22/92:17:30 < 17:59"

Specifies one or more ordered pairs of time segments consisting of a start time and a stop time, separated by a "<". The limits are inclusive and all data outside these limits will be excluded. The program will stop at the latest stop time. Be sure to reinclude the date when the times cross midnight.

UF_DEV

setenv UF_DEV "TF > /dev/nrsx0 TA > /dev/nrsx1"

In producing UF, data for each radar selected is written to a separate file or output device. If "/dev" is present anywhere in this string, the program assumes you are specifying a separate physical device for each radar.

UF_DIRECTORY

setenv UF_DIRECTORY "/scr/mead/uf_dir"

Causes UF files to be written to this directory instead of the DORADE_DIR.