isdparser-package: Parse NOAA ISD Files

In isdparser: Parse 'NOAA' Integrated Surface Data Files

Description

Parse NOAA ISD Files

Data format

Each record (data.frame row or individual list element) you get via isd_parse or isd_parse_line has all data combined. Control data fields are first, then mandatory fields, then additional data fields and remarks. Control and mandatory fields have column names describing what they are, while additional data fields have a length three character prefix (e.g., AA1) linking the fields to the documentation for the Additional Data Section at ftp://ftp.ncdc.noaa.gov/pub/data/noaa/ish-format-document.pdf

Data size

Each line of an ISD data file has maximum of 2,844 characters.

Control Data

The beginning of each record provides information about the report including date, time, and station location information. Data fields will be in positions identified in the applicable data definition. The control data section is fixed length and is 60 characters long.

Mandatory data

Each line of an ISD data file starts with mandatory data section. The mandatory data section contains meteorological information on the basic elements such as winds, visibility, and temperature. These are the most commonly reported parameters and are available most of the time. The mandatory data section is fixed length and is 45 characters long.

Additional data

Each line of an ISD data file has an optional additional data section, which follows the mandatory data section. These additional data contain information of significance and/or which are received with varying degrees of frequency. Identifiers are used to note when data are present in the record. If all data fields in a group are missing, the entire group is usually not reported. If no groups are reported the section will be omitted. The additional data section is variable in length with a minimum of 0 characters and a maximum of 637 (634 characters plus a 3 character section identifier) characters.

Remarks data

The numeric and character (plain language) remarks are provided if they exist. The data will vary in length and are identified in the applicable data definition. The remarks section has a maximum length of 515 (512 characters plus a 3 character section identifier) characters.

Missing values

Missing values for any non-signed item are filled (i.e., 999). Missing values for any signed item are positive filled (i.e., +99999).

Longitude and Latitude Coordinates

Longitudes will be reported with negative values representing longitudes west of 0 degrees, and latitudes will be negative south of the equator. Although the data field allows for values to a thousandth of a degree, the values are often only computed to the hundredth of a degree with a 0 entered in the thousandth position.

Author(s)

Scott Chamberlain [e-mail]

isdparser documentation built on Feb. 18, 2020, 1:09 a.m.