URGENT Air Data Files: Naming Conventions

N.B. The following guidelines apply to files containing NASA Ames formatted data, images or metadata associated to images. No special naming convention applies to files containing software, metadata pertaining to software or text documentation other than metadata.


  1. File name structure
  2. Centre identifier
  3. Data identifier
  4. Start date
  5. File name extension

1. File name structure

URGENT data or metadata file names are made of four fields. The first three fields are separated by an underscore sign ( _ ). The fourth field is separated from the third one by a dot ( . ).


Explanations on each of these 4 fields are given in the sections below.

For the sake of uniformity and to avoid very long file names, standard abbreviations have been adopted for the [centre-id] and for the [data-id]. Data suppliers, please make use of the provided abbreviations where possible. When making up new file name components, please try to keep them as short as possible. The total number of characters of data file names should not exceed 40. The list of adopted abbreviations will be completed as new standards need to be defined.

For a systematic list of abbreviations currently in use in URGENT data file names, please refer to the Alphanumeric Dictionary of Abbreviations used in URGENT File Names.

Apart from the file name extension (last field), files containing images and their associated metadata have the same name. When data exist both in the form of NASA Ames formatted fields and images, files also have the same name, except for the file name extension.

2. Centre identifier: [centre-id]

The [centre-id] section of the file name may refer to Abbreviations currently in use are listed in the Dictionary of Abbreviations used in URGENT File Names.

3. Data identifier: [data-id]

The [data-id] section identifies the nature of the data. For chemical compounds, the abbreviation used is the same for concentrations or mixing ratios. Abbreviations currently in use can be found in the Dictionary of Abbreviations used in URGENT File Names. A combination of not more than three abbreviations separated by a hyphen ( - ) may be used; for example: pritchatts_jo1d-jno2_000128.na. In the same way, some specification, if needed, can be added to the data symbol; for example, halfpenny_nox-10m_990612.na and halfpenny_nox-5m_990612.na will contain NOX concentrations measured at the altitudes of 5 and 10 metres above ground, at the same location and on the same date. Numbers may also be used to distinguish between different records of the same variable at the same site on the same date; for example: pritchatts_o3-01_000117.na, pritchatts_o3-02_000117.na, ..., pritchatts_o3-10_000117.na.

4. Start date: yymmdd

The yymmdd field refers to the date when the recorded observation started or to the initial date of the model scenario or to the date when the model results were issued (when the computation is not a scenario simulation).

yy last two digits of year number
mm month number (2 digits), from 00 to 12
dd day number (2 digits), from 00 to 31

5. File name extension: [ext]

The [ext] field depends on the file content as indicated in the table below.

[ext] File content
na NASA Ames formatted data & metadata
jpg, gif, etc images
txt metadata associated to images