Dataset: 1997_avhrr

AVHRR SST Images Satellite-derived AVHRR SST images for the US-GLOBEC Georges Bank Program study domain (combined Gulf of Maine & Georges Bank area):

     39.114 - 45.504 degree North latitude, 63.510 - 72.156 degree West longitude,

1 October 1993 - 2003. 

Data Provider: Dr. J. J. Bisagni, Department of Estuarine & Ocean Sciences, University of Massachusetts/Dartmouth, 200 Mill Rd., Suite 325  Fairhaven, MA 02719 508-910-6328. E-mail: jbisagni@umassd.edu.

Summary of Satellites Available, by Year

Notes

• The image aspect ratio is now correct. The images should be square. This problem within the IDL engine was solved November 2007 by switching to the ferret application to generate the images.
• Images are 512 X 512 pixels, possess a resolution of 1.4 km and are displayed as .GIF images.
• The archive "switches" from NOAA-11 to NOAA-9 during September 1994 due to the NOAA-11 failure in September 1994.
• Starting in 1994, all NOAA-9, -12 and -14 overpasses are remapped to the above domain and added to the archive on a daily basis.
• At the end of each month, all the month's images are precision navigated to within 1-2 pixels (1.4-2.8 km). NOAA-12 and -14 data are then saved to tape and deleted, due to calibration problems with NOAA-12 and -14 and to conserve disk space.
• During the initial data acquisition time, images from the current month may possessed navigation errors of up to 3-5 pixels or more in the X and/or Y directions.
• Starting August 2002, images from NOAA-17 ("b") became available. They seem to have replaced the NOAA-14 ("f") images.
• The colorbar used is derived from so-called Pete's Palette, or pete24, and converted to an equivalent palette in the ferret scheme. (See petespalette.spk.

Additional Information About Image Processing

All daily NOAA-11 Advanced Very High Resolution Radiometer satellite passes from 1 October 1993 on (generally 2 passes per day) have been remapped (earth-located) to our Georges Bank/Gulf of Maine "standard" region (given below) in a Mercator projection. Our standard region is bounded by:

• 39.114 - 45.504 degree North latitude, and
• 63.510 - 72.156 degree West longitude.

Precision navigation of each image to within 1 or 2 pixels has begun with the image file names receiving a ".nav" file extension when navigation is completed. Be aware that "un- navigated" images (".rmp" file extension) may possess navigation errors of up to 6 or 7 pixels in the meridional and/or zonal directions. Note that only ".nav" files are being served here at this time.

Daily remapping and weekly backups of these data will continue until after completion of the GLOBEC and Gulf of Maine field programs are completed. Each of these images are in University of Miami XDR04 format, consisting of an 8-bit, 512 X 512 pixel binary image, preceded by three 512-byte header records. The size of each image file (in uncompressed form) is ~250K bytes.

Up until July 2012, these images were uncompressed and converted from DSP compressed files to gif images via the ferret application for display by your favorite browser, such as Firefox, Internet Explorer, and Safari. Starting July 29, 2012, the gif images were served from files converted to gif images in a batch operation by Kent Gardner at UMass/Dartmouth and served online without using ferret.

The center latitude is 42.309 degrees North and the center longitude
is 67.830 degrees West. The slope and Y-intercept for converting the 8-bit image byte values to SST in degrees Centegrade are 0.125 and 0, respectively.

The equation information (slope + intercept) are IDENTICAL for both the OI and realtime images, with SSTs going from 0 through 31.875 degrees Centigrade.

XBrowse Software

Near real-time, daily, satellite-derived sea surface temperature (SST) data, which cover Georges Bank and the Gulf of Maine  were also available for browsing over the Internet in the Xbrowse format. However, this software is no longer available.

DODS/OPeNDAP System

These images are no longer viewable via DODS which has been replaced by OPeNDAP. The images cannot be viewable via OPeNDAP either, since the University of Miami's DSP format is no longer supported.

Downloading the image

You can capture the gif image as most browsers have that capability.  In addition, you can download the DSP compressed file for your onw use using the link on the web page. Please contact  Dr. James Bisagni directly. 

Last edited: August 8, 2012