The SeaBASS Regional Time Series Tool is designed to provide comparisons over time between averaged level 2 satellite-borne ocean color instrument observations as well as in situ measurements. For a given region, one or more satellite sensors must be selected and then all available satellite and in situ data collected within the bounds of the study site will be plotted for comparison in common figures and frequency distributions. User options are available to select a measurement product of interest (e.g., Rrs, IOPs, Chl, etc.), adjust the data averaging period (weekly, monthly, seasonal), the year range, and other graph options. Each region has a brief description that includes links to extra information about the primary in situ data sources and a map that shows the boundaries used to define each region. Users may also download the data that were used to generate the figures.
High quality in situ
measurements are prerequisite for satellite data product validation, algorithm development, and many climate-related inquiries. As such, the NASA Ocean Biology Processing Group
(OBPG) maintains a local repository of in situ
oceanographic and atmospheric data to support their regular scientific analyses. The SeaWiFS Project originally developed this system, SeaBASS, to catalog radiometric and phytoplankton pigment data used their calibration and validation activities. To facilitate the assembly of a global data set, SeaBASS was expanded with oceanographic and atmospheric data collected by participants in the SIMBIOS Program, under NASA Research Announcements NRA-96 and NRA-99, which has aided considerably in minimizing spatial bias and maximizing data acquisition rates. Archived data include measurements of apparent
and inherent optical properties
, phytoplankton pigment concentrations
, and other related oceanographic and atmospheric data, such as water temperature, salinity, stimulated fluorescence, and aerosol optical thickness. Data are collected using a number of different instrument packages
, such as profilers, buoys, and hand-held instruments, and manufacturers on a variety of platforms
, including ships and moorings.
The SeaBASS validation system is designed to provide ground-truth comparisons between in situ measurements and coincident satellite-borne ocean color instrument observations. The results are displayed and distributed via a web-based search engine, available for assessments of satellite measurements and algorithm performance. This article briefly summarizes the following steps involved in this system of creating match-ups: 1) Assembly of in situ data; 2) Reduction of in situ data to relevant observations; and 3) Preparation of coincident satellite imagery.
The SeaBASS website contains several tools and options to help you find data files and products. The main options for aquiring data can be found under the "Get Data" drop-down in the main menu. The "File Search" is a good starting place as it allows you to perform custom searches for data files based on parameters such as particular measurement types (e.g. CTD, Chl, etc), investigator names, date, location and other options. Alternately, you can manually browse through files and folders using the "Archive" option, but it is generally recommended to use the File Search which simplifies downloading multiple files. The "Validation Search" allows you to search for and download post-processed datasets of successful match-ups between satellite sensors and field measurements. "NOMAD" will direct you to a specific subset of co-located measurements that were organized for algorithm development.
The "Lists" main menu option provides links to pages that contain alphabetically sorted lists of different types of information archived in SeaBASS. Visit those pages to view all contributing Investigators, Affiliations, Cruises and Experiment. These options can be useful for cross-referencing, for example, you can click on a particular cruise page to see a summary of all the associated data, or you can click on a particular investigator to see a sortable list of all the experiments and cruises they have contributed to.
The "Wiki" includes a number of articles and documents related to a variety of SeaBASS topics. You can browse through the articles or else use the search bar to look for articles that match particular keywords. For example, use the search to find an article containing a MATLAB SeaBASS file reader or a small dataset containing examples of hyperspectral Rrs measurements.
If you are interested in contributing data to SeaBASS, please visit the links under "Contribute Data" in the main menu for more information. You are also welcome to reach out with questions to the people listed under "Contact Us."
This page has been set up for documents and information that will be shared at the NASA Particle Absorption Workshop (June 2014).
Questions we often get asked.
NOMAD is a publicly available, global, high quality in situ bio-optical data set for use in ocean color algorithm development and satellite data product validation activities. Data products include coincident observations of water-leaving radiances and chlorophyll a concentrations, along with relevant metadata, such as the date, time, and coordinates of data collection and binary processing flags. Inherent optical properties (IOPs; e.g., spectral absorption and backscattering coefficients) and aerosol optical thicknesses have been or will be included in the near future. The entire dataset is available via a digital text file provided below under Downloads. Additional background details, such as the motivation for creating such a data set, and a historical perspective of such data sets, are provided in the Werdell and Bailey reference listed below.
NOMAD is available for research uses only. It was compiled by the NASA Ocean Biology Processing Group at Goddard Space Flight Center, Maryland, USA, using generous data contributions from the ocean color research community. Source bio-optical data are available online via a suite of SeaBASS Search Engines. Optimum interpolation (OI) sea surface temperature (SST) data were acquired from the NOAA Climate Diagnostics Center. ETOPO2 water depths were acquired from the NOAA National Geophysical Data Center. NOMAD Data access and use are governed by the SeaBASS Data Access Policy. Please direct comments, questions, and identified outliers to the SeaBASS Administrator.
Access to the data archived within SeaBASS follows the NASA Earth Science Data and Information Policy.
NASA's Earth Science program was established to use the advanced technology of NASA to understand and protect our home planet by using our view from space to study the Earth system and improve prediction of Earth system change. To meet this challenge, NASA promotes the full and open sharing of all data with the research and applications communities, private industry, academia, and the general public. The greater the availability of the data, the more quickly and effectively the user communities can utilize the information to address basic Earth science questions and provide the basis for developing innovative practical applications to benefit the general public. In this regard, all users incorporating SeaBASS data into their research are expected to acknowledge both their data sources (the original data contributors and SeaBASS) and NASA, and to abide by the Access Policy.
The following file contains seven examples of hyperspectral remote sensing reflectance (Rrs) spectra. These spectra were subjectively selected and compiled with the goal of providing examples of a variety of spectral shapes from different waters. Please read below for more information on the file contents.
This data file is available for research uses only. It was compiled by the NASA Ocean Biology Processing Group
at Goddard Space Flight Center, Maryland, USA, using generous data contributions from the ocean color research community. Source bio-optical data are available online via a suite of SeaBASS Search Engines. Access and use are governed by the SeaBASS Data Access Policy
. Please direct comments, questions, and identified issues to the SeaBASS Administrator