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Frequently Asked Questions
This section gives the answers to many of our most frequently asked
questions. If your question is not answered here, please submit your
query to the CoastWatch Help Desk at CoastWatch.Info@noaa.gov.
CoastWatch is a NOAA-wide program comprised of Central Operations and
six Regional Nodes. Our mission is to process satellite data and
provide oceanographic products to federal, state and local marine
scientists, coastal resource managers, and the general public. Data
are processed in near real-time and are usually only a few hours old.
Each CoastWatch Regional Node has a unique website for data
distribution and specialized products and projects which utilize
CoastWatch data. Links to these sites are found on the Regional Offices page.
There are many uses for CoastWatch data. For instance, temperature
images are used to locate fishing spots and for forecasting weather.
Ocean color images help scientists track biological changes in the
ocean, while sea surface wind images are used primarily by
meteorologists and boaters.
No, CoastWatch covers more than just the coastal areas of the U.S.
Depending on the region of interest, there could be data covering as
far out as 500 nautical miles off shore or the entire Great Lakes. In
addition to these regions, CoastWatch will also be providing data for
the open ocean. Look for OceanWatch to be coming soon as we continue
to expand our region areas and move toward global coverage.
No, CoastWatch does not normally provide data for any of the lakes
throughout the U.S., other than the Great Lakes. However, for the
2000 Winter Olympics in Salt Lake City, CoastWatch provided data for
the Great Salt Lake. This SST data proved useful for meteorological
forecasts and is still being processed today. The data can be
retrieved from the NOAA CLASS
site.
CoastWatch provides data from several satellite platforms. For more
detailed information, follow the "Data Products" link to the left:
- Sea surface temperature: POES/AVHRR, GOES/Imager,
MODIS/Aqua and Terra, and as an experimental product TRMM/TMI
- Ocean Color: GeoEye/SeaWiFS and MODIS/Aqua and Terra
- Wind: DMSP/SSMI and QuikSCAT/SeaWinds
No, CoastWatch does not have aerial photos. We provide only satellite
ocean remote sensing products for regions around the U.S. These
products can be found by using the "Product Search" link to the left.
No, although there may occasionally be satellite images of hurricanes
posted on the site for general interest, CoastWatch is not responsible
for distributing hurricane information. Please visit the National Hurricane Center website
for official hurricane images, forecasts, and advisories.
Central Operations maintains the CoastWatch home page
and each CoastWatch Regional Node has a unique website for
data distribution specific to their region. Links to these sites are
found on the Regional Offices page. In
addition, CoastWatch has an anonymous FTP server for
accessing the data. Presently, only AVHRR and MODIS products are
available, but all other products will be made available soon.
All CoastWatch products can be found by using the "Product Search"
link to the left. This is a search interface that provides access to
the satellite ocean remote sensing data and products CoastWatch has to
offer. Data selection is broken down into the following categories:
geographic region, product, sensor, satellite, and date. To browse
through the data by sensor using a directory tree only, see the Data Index.
Accuracies vary with each type of sensor and processing used.
Validation for most products are available through websites that
describe the methodology and techniques used to create CoastWatch
products. The Validation section
of the Links page provides access to these sites.
Since CoastWatch doesn't provide the binary data in FLT/HDR format for
MODIS, you can convert the GeoTiFFs (which contain 8-bit integers) to
grids and calculate the SST from the GeoTIFF values using the below
equation. In doing so, you must have the Spatial Anyalyst extension
ON and the TIFF 6.0 extension OFF.
(((SST_grid*0.14575))-0.8676)
The result should be a floating point grid containing the SST values.
Remember, the mathematical order of operations in ArcView 3.x is left
to right.
Sea surface temperature data are stored at the NOAA CLASS site. To order and
download data, you must first register on the website. Once the order
is placed, instructions will follow on how to retrieve the data which
will be staged on an anonymous FTP server.
No, you do not need to register for MODIS ocean color products, nor
for SeaWiFS imagery. The SeaWiFS imagery purchased and processed by
NOAA can be viewed online through this website, using "Product
Search". However, if you need access to the data (i.e., HDF files) or
near real-time SeaWiFS imagery (i.e., for coastal management or
resource monitoring) then you must become a registered user, due to
licensing contracts with GeoEye.
The satellite that supports SeaWiFS is a commercial platform owned by
GeoEye. Because this is a commercially owned and operated platform,
NOAA must purchase data subject to a contract that defines the
appropriate use of ocean color data derived from SeaWiFS. NOAA
purchased data is restricted to "civil marine" operational use and is
intended for civil authorities (federal, state, and local governments)
for watershed management and monitoring. Data for research purposes
may be obtained from NASA under a separate agreement with GeoEye.
You must meet the following criteria:
- be a qualified NASA SeaWiFS user (Dear Colleague Letter in
place) with a need for NRT processing/NOAA algorithms in support of
NOAA projects
- be a coastal manager (local, state, federal government) with a
need for NOAA operational data for civil marine management
- have an understanding of the NOAA
CoastWatch SeaWiFS Data Use Policy
If you meet these criteria or have additional questions, then contact
Kent Hughes, CoastWatch
Program Manager to request access. If you only need SeaWiFS data
solely for research purposes, you should request data from the NASA
SeaWiFS Project.
All current MODIS Aqua and Terra data are available in HDF format on
this website for up to 14 days. However, PNG and GeoTIFF's are
available from 6 - 24 months. Archived data are available through the
NASA
Distributed Active Archive Center and should be used for any data
older than 14 days.
CoastWatch provides near real-time ocean surface wind products with
data from the QuikSCAT satellite and the Defense Meteorological
Satellite Program (DMSP) satellites. Although the ocean surface wind
products appear similar, each product has unique characteristics
dependent on sensor characteristics and wind derivation methods. The
QuikSCAT SeaWinds products use color as well as wind-barb notation to
depict velocity (wind speed and direction), while the DMSP SSM/I
products show only wind speed.
QuikSCAT/SeaWinds HDF and SHP files are available on this site for up
to four weeks. GeoTIFFs and PNGs are available up to five months.
For dates earlier than these, please visit NASA JPL.
CoastWatch supports a variety of data formats for satellite images.
The primary format is the CW HDF (Hierchical Data Format), which
retains highly accurate data values and metadata required for
scientific analysis. Image products may be available in GeoTIFF, PNG,
or GIF formats. These products are easily viewable in graphics
applications or web browsers. More information on these formats is
located on the Data Formats page.
CoastWatch provides various types of software and utilities for data users.
One in particular, is the CoastWatch Software Library and Utilities
package. This package allows data users to easily manipulate and
visualize satellite data in both the new CoastWatch HDF (.hdf) files
and the older CoastWatch IMGMAP (.cwf) files. The utilities are
composed of both graphical and command-line tools that can read
CoastWatch data and allow the user to convert or customize the display
of CoastWatch products.
The latest version of the software and utilities package, 3.2.1, is
available for free through this website. New versions are released
periodically.
Yes, all CoastWatch products are now offered in CW HDF format, which is
usable with the CoastWatch Utilities.
In addition to the default set of palettes, users may create their own
palette files in XML format and store them in a special application
data subdirectory. See the 'Help and Support' menu item under the
'Help' menu within CDAT.
As of version 3.2.1, Java is built into the CoastWatch Utilities
installation package. For previous versions, consult the user's guide
for the appropriate Java version and download it from java.com/getjava.
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