Standardized Fields and Units

Below is a table of the standard field names and associated units for use in submitting data to the SeaBASS bio-optical archive. The field names are NOT case sensitive. Use the search bar or the find function in your browser to search the table for words or patterns found in the field names, units or descriptions.


Special notes regarding wavelength-specific measurements: There are two different ways to indicate wavelengths in a SeaBASS file. If metadata such as date, location or depth vary within a file, then wavelength should be appended to the field name for every measurement combination. For example, downwelling irradiance measured at 412.3 nm would become 'Ed412.3' (listed along with any other Ed measurements, like Ed416.2, Ed419, etc), or aerosol optical thickness measured at 1020 nm would become 'AOT1020'. Alternately, if date, location and depth are assumed to be approximately constant for all measurements in the file, then use the field 'wavelength' to provide a column of the measured wavelengths and don't include them as part of the field names (this layout is commonly used for reporting spectrophotometric measurements).


To provide additional information about a field, for example, the standard deviation of the reported average of replicate measurements, refer to the tables of field name suffixes and modifiers below. These tables offer consistent patterns used to name certain types of measurements without having to hardcode a new name in SeaBASS. For example, standard deviations are explained in the table of suffixes, for example "chl_sd" or "ag510_sd". The table of modifiers includes ways to dynamically report special measurements, such as size fractionated data (see _###filt and _###prefilt). Please contact SeaBASS staff if you want to discuss adding new fields.


Notes on HPLC pigment field names


To assist with the standardization of SeaBASS data files, the SIMBIOS Project developed feedback software, named FCHECK, to evaluate the format of submitted data files. Since then, it has been rebuilt from the ground up by the SeaBASS development team to make it available to the end-users. Using FCHECK, contributors may evaluate the format of their SeaBASS-compatible files prior to submission.

Metadata Headers

Standard metadata headers are required in every SeaBASS file. Select a header to view its definition, or if you are just getting started, scroll down just below the table of content to see an example header.

Data Format and Submission

To account for the continuous growth of the bio-optical data set and the wide variety of supported data types, the NASA Ocean Biology Processing Group felt it essential to develop efficient data ingestion and storage techniques. While this requires a specific data file format, the data protocols were designed to be as straightforward and effortless as possible on the part of the contributor, while still offering a useful format for internal efforts. The system was intended to meet the following conditions: simple data format, easily expandable and flexible enough to accommodate large data sets; global portability across multiple computer platforms; and web accessible data holdings with sufficient security to limit access to authorized users.

readsb (MATLAB)

readsb.m is a MATLAB function designed to open and read data files that are in a SeaBASS format. Some SeaBASS files can be opened using MATLAB's various built-in import functions, however many of the built-in methods are unsuited to efficiently open SeaBASS files without errors or significant manual intervention. Using this function, data outputs can simply be returned as either a cell array or as a structure where the names of the data field headers from the SeaBASS file are array field names (e.g. dataStructure.DEPTH, dataStructure.CHL, dataStructure.LW412). File metadata information is also returned in a separate structure (and arrays, if desired.)

AERONET Ocean Color

The NASA OBPG routinely downloads data from the AERONET-Ocean Color website for use in satellite sensor validation match-up analysis. As described by Zibordi et al. (2009), the AERONET-OC network consists of globally distributed autonomous radiometer systems maintained at fixed offshore sites. Please refer to the rest of the information in this article for details on how to acknowledge the use of AERONET-OC data and how the OBPG processes these data.

SST Validation Description

This article is still under construction (2019-03-27)

The SeaBASS sea surface temperature (SST) validation system is designed to provide ground-truth comparisons between in situ measurements and coincident satellite-borne ocean color instrument observations. Per satellite sensor, the results are compiled into files containing all successful match-ups from around the globe for a given calendar day (i.e., 1 validation file per satellite sensor per day). Users may search for results using a web-based search engine or API. This article briefly summarizes how to download these results, as well as describing the steps involved in this system of processing and creating match-ups.

Satellite Validation Match-Up Tools (Portable)

These validation match-up tools allows Users to
  1. find relevant OB.DAAC satellite granules from in situ points or a SeaBASS data file and
  2. generate coincident satellite validation match-ups for those points.
These tools are downloadable for Users to run individually, external to the official SeaBASS validation search. These tools are designed to replicate some of SeaBASS validation search's core functionality, with the exception that these tools do NOT adjust in situ data to water-leaving values.
These validation match-up tools are served as part of SeaDAS and apply the default recommended match-up exclusion criteria, as set forth in S.W. Bailey and P.J. Werdell, "A multi-sensor approach for the on-orbit validation of ocean color satellite data products", Rem. Sens. Environ. 102, 12-23 (2006).

User Resources

The following section contains various examples for SeaBASS submitters and users.

readsb (Python) is a Python module containing a set of classes designed to open, read, and manipulate data files that are in a SeaBASS format. While many of Python's built-in functions may be used to read SeaBASS files, this module leverages Python libraries and tools to efficiently read, sort, mask, and return the contained data for easy use without errors or significant intervention. Using this function, data outputs will be returned as data structures containing the file's header information (metadata) as an array of strings, the file's comments as an array of strings, the file's missing data, above detection limit, and below detection limit values (if present), the file's variable and unit lists as an Ordered Dictionary indexed by variable name, and the file's data as an Ordered Dictionary indexed by variabile name. Additionally, optional arguments flags that may be toggled are mask_missing, mask_above_detection_limit, and mask_below_detection_limit (all set true by default), which remove the header-defined values for these fill values, replacing them with NaN.