Data Distribution Formats
Data File Formats
GCE-LTER data sets are generally available in multiple file formats to suit various end-user requirements and software capabilities. The list below summarizes the main features of these formats and recommendations for common types of software. Technical details are described in the next section.
Technical Format Specifications
Tabular GCE-LTER data sets are primarily stored as structured MATLAB® data files with encapsulated documentation (metadata), QA/QC rules and qualifier flags to support data analysis, transformation and formatting. Custom MATLAB programs in the GCE Data Toolbox are used to export the data sets in a wide variety of ASCII and MATLAB formats with documentation formatted in various styles.
Technical specifications for
GCE distribution file formats are described in the table below.
Contact the GCE
Information Manager to request data in a custom format or to request a
basic statistical treatment of the data (e.g. statistics for values aggregated
by one or more key columns).
GCE File Versioning Information
All files in the GCE Data Catalog are assigned version numbers to assist users in identifying whether changes have been made to a data set since its original release. Version numbers are assigned according to the following scheme:
[Major Version].[Minor Version] (with 1.0 as the first release)
'Major Version' is the primary version of the data set, based on composition of the data table and metadata descriptors. Updates to this number indicate significant changes to the data set, such as addition or removal of data columns or significant changes to data values or metadata descriptors; users who have downloaded an earlier version are encouraged to download the update and re-evaluate any analyses based on the data.
Changes to 'Minor Version' usually represent refinement of metadata descriptors or reformatting of data sets and metadata to comply with new display standards. Users are encouraged to look at the data set processing history listed in the updated metadata to determine whether or not the update is important to their work, but re-downloading the data set is usually not necessary.
As of October 2003, major and minor version numbers are appended to all GCE data and metadata file names (e.g. PHY-GCEM-0310a1_1_1.MAT for PHY-GCEM-3010a1 version 1.1). This change was made to improve data file version control in GCE archives, and to simplify end-user assessment of data set lineage and updates.
Data Update Notification
As a service to project participants and the scientific community, update notifications are sent via email whenever changes are made to a data set listed in the data catalog. Announcements are sent to project participants using the GCE-LTER mailing list and to individual email addresses of public users who have downloaded an earlier version of the data set and requested update notification on the data access form.
This material is based upon work supported by the National Science Foundation under grants OCE-9982133, OCE-0620959 and OCE-1237140. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.