DC*

Schema definition files are ASCII text files that contain lines of text defining the structure of MD files for point-source data types. To create a schema definition file, use a standard editor to enter a set of text lines. The file serves as input to the schema registration program, SCHE, that reads the text lines and forms a blueprint of the MD file's structure. SSEC distributes the schema definition files below with every McIDAS upgrade.

Schema file	Contents
DCFO14	NGM MOS forecasts
DCIRAB	international radiosonde observations
DCISEN	isentropic data
DCISFC	international surface hourly observations
DCISHP	international ship and buoy observations
DCPIRP	PIREP, AIREP and ACARS data
DCSYN	surface synoptic observations

Because schema definition files form the input to an application, you must use the formats provided below for each text line of a schema file.

File header

A header is required for each schema definition file. Its format is shown below, followed by a table of parameter definitions.

SCHEMA name version date id "description

Parameter	Definition
name	four-character schema name
version	schema version number
date	Julian day the schema definition file was created
id	schema identification number
"description	comments

Row and column headers

Either a row header or a column header is required for each schema definition file. The row and column header formats are shown below, followed by a table of parameter definitions.

ROWS nrows "description
rkeyname1 rscale1 runits1 "description
...
rkeynameN rscaleN runitsN "description

Parameter	Definition
nrows	default number of rows to make for this MD file
rkeyname1 ... N	name of the first and Nth row header keys
rscale1 ... N	scale factor of the first and Nth row header keys
runits1 ... N	physical units of the first and Nth row header keys
"description	comments

COLUMNS ncols "description
ckeyname1 cscale1 cunits1 "description
...
ckeynameN cscaleN cunitsN "description

Parameter	Definition
ncols	default number of columns to make for this MD file
ckeyname1 ... N	name of the first and Nth column header keys
cscale1 ... N	scale factor of the first and Nth column header keys
cunits1 ... N	physical units of the first and Nth column header keys
"description	comments

Data lines

Use the format below for the data lines.

DATA
dkeyname1 dscale1 dunits1 "description
...
dkeynameN dscaleN dunitsN "description

Parameter	Definition
dkeyname1 ... N	name of the first and Nth data keys
dscale1 ... N	scale factor of the first and Nth data keys
dunits1 ... N	physical units of the first and Nth data keys
"description	comments

Repeat groups

Repeat groups are optional. They are useful when data of the same type is repeated within the data portion of a record. The format is shown below.

REPEAT nrepeats
rkeynames rscales runits "description

Parameter	Definition
nrepeats	number of repeat groups in the data portion of the schema definition
rkeynames	names of the repeated data keys
rscales	scale factors of the repeated data keys
runits	physical units of the repeated data keys
"description	comments

McIDAS Programmer's Manual

DC*

File header

Row and column headers

Data lines

Repeat groups

End-of-schema and comment formats

API functions