BADC Doc: ACSOE NASA Ames file format explained
Source: environment.data.gov.uk (2018-06-19)

ACSOE MAGE EAE-96 and EAE-97: Airborne, Shipborne and Ground-based Measurements of Aerosols and Gases in the Marine Boundary Layer. The Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE) Marine Aerosol and Gas Exchange (MAGE) Eastern Atlantic Experiment (EAE) aimed to quantify input of Dimethyl sulphide (DMS) into a parcel of air, examine the oxidation of DMS and its reaction with nitrogen species with time, investigate the formation of new particles as a results of these transformations, and to discriminate between natural and anthropogenic fractions of sulphur and nitrogen using isotopic measurements. To meet these aims, numerous species of gases and aerosols in the marine boundary layer were measured on land from the Mace Head Research Station, on sea from the RSS Challenger and in the air from the Cranfield Jetstream Research Aircraft during two separate campaigns in 1996 and in 1997, and the observations are currently stored under this collection.

NASA-Ames files

The concept of a NASA-Ames format file originated during the 1987 Stratosphere Troposphere Exchange Project (STEP) (/data/step/)when it was decided to collect all the campaign data on a single medium which could be accessed easily by all participants during the campaign. For compatibility only ASCII characters were allowed and every NASA-Ames file had to consist of a computer-readable ASCII header followed immediately by one or more ASCII data tables.

The file header, which is written in computer and human readable form, describes in full detail the properties of the data that follow it such as the units and the scaling, the default values substituted for missing data and the layout of the table (or tables).

Although the NASA-Ames format has been adopted for several campaigns, particularly those involving coordinated aircraft and ground-based measurements, these notes are directed specifically at participants in the ACSOE (Atmospheric Chemistry Studies in the Oceanic Environment) special community programme of NERC. Because of the wide spectrum of measurements being made during this programme and the large number of experimenter groups involved, using NASA-Ames data format holds significant advantages particularly when it comes to early exchange of data. However, in spite of the fact that these notes are intended primarily for ACSOE data suppliers, all users of the format should be able to glean something meaningful from them.

The ACSOE data files conform to the NASA-Ames standard, although in addition, special keywords have been included in the header to simplify the task of creating a file catalogue.

For a comprehensive description of NASA-Ames format see "A General Format for Data Exchange" written by the format originators Gaines and Hipskind and available in PostScript format from /badc/acsoe/doc.

The rest of the information is organised into the following categories:
- The file header (header.html)
- Interpreting FFI (FFI.html) (the File Format Index)
- File ingestion (ingest.html) at BADC
- NACHECK (program.html) - a FORTRAN program to examine NASA-Ames format files
- Run NACHECK (/cgi-bin/dataex_file.cgi.pl) - Run the NACHECK program to check a NASA-Ames format file
- Checklist (checklist.html) for (ACSOE) file submission