Level 3
18 km resolution global and regional composites of derived geophysical
parameters.
January, 1979
April, 1979
CZCS, which operated from November 2, 1978 to June 22, 1986, was a
multi-spectral line scanner devoted principally to measurements of ocean
color. It had six spectral bands (channels), four of which were devoted
to ocean color, each having a 20 nanometer bandwidth and centered at 443,
520, 550, and 670 nanometers. These are referred to as channels 1 through
4, respectively. Channel 5 sensed reflected solar radiance and had a 100
nanometer bandwidth centered at 750 nanometers and a dynamic range which
was more suited to land. Channel 6 operated in the 10.5 to 12.5
micrometer region and sensed emitted thermal radiance for derivation of
equivalent black body temperature.
This document describes the level 3 18-km resolution DSP (PST and COMP
format) Coastal Zone Color Scanner data products archived at the Goddard
Space Flight Center (GSFC) Distributed Active Archive Center (DAAC).
Other CZCS data products archived at Goddard include 4 km resolution CZCS
level 1A & 2 products in HDF format and CZCS level 1 1-km resolution
data. The characteristics of the CZCS Sensor are described in the Coastal Zone Color Scanner Sensor
Guide and the Nimbus 7 platform is described in the
Nimbus 7 Platform Guide.
Table of Contents
- Document Information
- Investigator(s)
- Dataset Information
- Theory of Measurements
- Equipment
- Procedure
- Observations
- Data Granularity
- Data Description
- Data Manipulations
- Errors
- Notes
- Application of the Dataset
- Dataset Plans
- References
- Related Software
- Data Access
- Output Products and
Availability
- Glossary of Terms
- List of Acronyms
- Dr. Gene Feldman
- Goddard Space Flight Center, Code 610.2.3
- Greenbelt, MD 20771
- (301)286-9428
- email: gene@seawifs.gsfc.nasa.gov
- Dr. Chuck McClain
- McClain - Goddard Space Flight Center, Code 971
- Greenbelt, MD 20771
- (301)286-8134
- email: mcclain@calval.gsfc.nasa.gov
- Dr. Wayne Esaias
- Goddard Space Flight Center, Code 971
- Greenbelt, MD 20771
- (301)286-5465
- email: wayne@pelican.gsfc.nasa.gov
Coastal Zone Color Scanner
- CZCS Data -
- Dr. Gene Feldman
- Goddard Space Flight Center, Code 610.2.3
- Greenbelt, MD 20771
- (301)286-9428
- email: gene@seawifs.gsfc.nasa.gov
- Software -
- Dr. Bob Evans
- University of Miami, RSMAS/MPO
- 4600 Rickenbacker Causeway
- Miami, FL 33149
- (305)361-4799
- email: bob@rrsl.rsmas.miami.edu
-
-
For most regions of the world, the color of the ocean is determined
primarily by the abundance of phytoplankton and their associated
photosynthetic pigments. As the concentration of phytoplankton pigments
increases, ocean color shifts from blue to green. The Coastal Zone
Color Scanner (CZCS) was a multi-spectral line scanner developed by
NASA to measure ocean color as a means of determining chlorophyll
concentrations and the distributions of particulate matter and
dissolved substances.
-
-
The purpose of the CZCS on Nimbus-7 was to obtain data on the
temporal and spatial distribution of phytoplankton biomass and primary
production, a better understanding of processes regulating the growth
of phytoplankton, and uinsight into the ultimate fate of this
organically fixed carbon. Satellite observations of ocean color were
necessary to provide reliable estimates of marine phytoplankton biomass
on synoptic scales useful in studies of phytoplankton biological
dynamics. The mission objectives for the CZCS were to obtain
observations of ocean color and temperature, particularly in the
coastal zones, which would provide data with sufficient spatial and
spectral resolution for the following applications:
- Measure concentrations of chlorophyll-a and phaeophytin.
- Map biologically productive areas.
- Map suspended sediment distribution and determine the type of
materials suspended in the water.
- Map Gelbstoffe (yellow substances) as an indicator of
salinity.
- Detect pollutants in the upper level of the oceans.
- Map temperature of coastal waters and the open ocean.
- Study the interactions between coastal effluents and open
waters.
-
The Level 3 monthly and seasonal composites are arithmetic averages
of radiances and pigment concentrations for all pixels containing valid
data from daily composite images. The annual composite is based on 12
monthly composites, (not 365 daily composites). None are true means.
For example, the values shown in the Beaufort Sea in the annual
composite do not include any winter values when it was covered by ice.
The climatologies (for the month of June as an example) are based upon
arithmetic averages of pigment for the month of June in the years 1979
through 1986.
Organic and inorganic particulate matter or dissolved substances
suspended in water affect its color. Ocean water containing very little
particulate matter scatters as a Rayleigh scatterer, producing the
well-known deep purple or bluish color of the open sea. As particulate
matter is added to the water, its light scattering characteristics change
such that different water colors are observed. Phytoplankton, for instance,
have specific absorption characteristics and normally change the water to a
more greenish hue, although some phytoplankton (such as various "red tide"
organisms) can change the water to colors such as red, yellow, blue-green
or mahogany. Inorganic particulate matter in water, such as the terrigenous
outflow from rivers, has a different color from organic material, typically
brownish in color but sometimes varying with red. Differentiating between
suspended organic and inorganic matter remains a challenge to ocean color
scientists today. By sensing the color with very high signal-to-noise
ratios in several narrow bands, CZCS provided a mechanism for correlating
water color with its contents for the first time.
-
CZCS had a scan width of 1556 km centered on nadir, and the ground
resolution was 0.825 km at nadir. Channels 1-4 were devoted to ocean
color, each having 20 nanometer bandwidth and centered at 443, 520,
550, and 670 nanometers respectively. Channel 5 sensed reflected solar
radiance, but had a 100 nanometer bandwidth centered at 750 nanometers
and a dynamic range which was more suited to land. Channel 6 operated
in the 10.5 to 12.5 micrometer region and sensed emitted thermal
radiance for derivation of equivalent black body temperature. Channel 6
failed early in the mission (see below).
CZCS was launched aboard Nimbus-7 in October 1978. Due to the power
demands of the various onboard experiments, the CZCS operated on an
intermittent schedule. The infra-red/temperature sensor (channel 6
10.5-12.5 microns) failed within the first year. During 1981, it was
determined that the sensitivity of the other CZCS sensors was degrading
with time, in particular channel 4. Sensitivity degradation was
persistent and increased during the rest of the mission.
In mid-1984, NIMBUS-7 mission personnel experienced turn-on problems
with the CZCS system which were related to power supply problems and the
annual lower power summer season of NIMBUS-7. Spontaneous shutdown of the
CZCS system also began occurring. These problems persisted for the rest
of the mission. From March 9, 1986 to June, 1986, the CZCS system was
given highest priority for the collection of a contemporaneous data set
of ocean color. It was turned off in June, at the start of the low power
season, with the intention of turning it back on in December when power
conditions would be more favorable. Attempts to reactivate CZCS in
December 1986 failed. The CZCS sensor was officially declared
non-operational on 18 December 1986.
-
Nimbus-7, launched in October 1978, was a research-and-development
satellite serving as a stabilized, earth-observing platform for the
testing of advanced systems for sensing and collecting data in the
pollution, oceanographic, and meteorological disciplines. It
provided an opportunity to assess each instrument's operation in
the space environment and to collect a sizable body of data with
the global and seasonal coverage needed for support of each
experiment. The mission also extended and refined the sounding and
atmospheric structure measurement capabilities demonstrated by
experiments on previous Nimbus observatories.
Nimbus-7 sensors included a limb infrared monitor of the
stratosphere (LIMS), stratospheric and mesopheric sounder (SAMS),
coastal-zone color scanner (CZCS), stratospheric aerosol
measurement (SAM II), earth radiation budget (ERB), scanning
multichannel microwave radiometer (SMMR), solar backscatter UV and
total ozone mapping spectrometer (SBUV/TOMS), and
temperature-humidity infrared radiometer (THIR). These sensors were
capable of observing several parameters at and below the
mesosphere. After 11 years in orbit, three experiments, SAM II,
SBUV/TOMS, and ERB, were still functioning successfully. Nimbus 7
was finally retired in 1995.
Nominal orbit parameters for the Nimbus-7 spacecraft were:
Launch date 10/24/78
Orbit Sun-synchronous, near polar
Nominal Altitude (km) 955
Inclination (deg) 104.9
Nodal Period (min.) 104
Equator Crossing Time 1200 noon (ascending)
Nodal Increment (deg) 26.1
-
CZCS was a cross-track scanning system. The Instantaneous
Field of View (IFOV) of each detector was .865 mrad, yielding
a resolution of 825 m at the satellite subpoint. The swath
covered 1566 km in width from a maximum scan angle of
approximately 40 degrees. 1970 samples per scan were
collected for channels 1-6. This yielded 94,560 samples per
second with an 8 bit (256 level) quantizing resolution. Data
were then transmitted to a receiving station at a rate of 800
kbps.
-
Ball
Aerospace and Technologies Corporation ,
(http://www.ballaerospace.com/).
-
Prelaunch calibration of the CZCS used a 76 cm diameter
integrating sphere as a source of diffuse radiance for
channels 1 through 5, and a blackbody source for calibration
of channel 6. The integrating sphere was especially
constructed for calibration of the CZCS, and was calibrated
by a standard lamp from the National Bureau of Standards,
utilizing a spectrometer and another integrating sphere to
transfer calibration from the lamp to the sphere.
In addition to the sphere and the blackbody, a collimator
was used to calibrate the CZCS in vacuum testing. In-flight
calibration of the CZCS is accomplished for the first five
bands by using a built-in incandescent light source. This
in-flight calibration source was calibrated using the
instrument itself as a transfer against the referenced sphere
output.
Channel 6 was calibrated by viewing the blackened housing
of the instrument whose temperature was monitored. Deep space
is another calibration source viewed during the 360 degree
rotation of the scan mirror.
For further details on the CZCS sensor and the Nimbus 7
satellite, please consult The Coastal
Zone Color Scanner Starter Kit,
(http://disc.sci.gsfc.nasa.gov/oceancolor/docs/CZCS_Starter_kit.shtml>)
and the
Nimbus 7 Platform Guide ,
(http://podaac-www.jpl.nasa.gov:2031/SOURCE_DOCS/nimbus7.html).
-
The raw data from the six channels of the CZCS were either
directly transmitted to the ground station in real-time or
recorded on the satellite tape recorder for later playback
and transmission to the ground station. Data were stored on
magnetic tape and sent to the Image Processing Division (IPD)
at Goddard Space Flight Center (GSFC). In addition to
radiance measurements, these data also include the
calibration lamp data and Image Location Data (ILT).
-
(This information is not available for CZCS.)
-
(This information is not available for CZCS.)
Each Level 1 granule is a partial orbital swath with a maximum
of 2 minutes of data. One two-minute CZCS scene covers
approximately 1.3 million square kilometers of the Earth's
surface. Each Level 3 granule is either a single global or
regional composite representing a daily, weekly, monthly or
annual average.
-
Spatial Coverage is global with an emphasis on coastal
regions. Spatial coverage varied widely and was very
irregular. The first plot below shows a composite of the
spatial coverage for the entire CZCS mission while the
following 9 plots show the geographic distribution of CZCS
data for each of the nine years from 1978-1986. Each dot on
these plots represents the center point of one CZCS Level 1
scene. These images show the irregular spatial distribution
of the CZCS data set graphically.
![78-86](https://webarchive.library.unt.edu/eot2008/20090513165839im_/http://daac.gsfc.nasa.gov/oceancolor/images/all_thumbnail.gif)
Level 3 CZCS scenes have a spatial resolution at nadir of
18.5 km for photosynthetic pigment distribution.
Level 3 composite data is plotted on an Equal Angle Grid. The
data are binned to a fixed, linear latitude-longitude (equal
angle) grid of dimension 1024 (latitude) x 2048 (longitude),
with an approximate 18.5 km resolution at the equator. Both
full global and selected sectored regional images are
available. The regional images have the following upper left
corner (ulc) and lower right corner (lrc) latitudes and
longitudes:
REGION ulc lat.,lon. lrc lat.,lon.
North Atlantic 69.873, -88.506 -19.951, 1.318
N.E. Pacific 61.260, -162.334 -28.564, -72.500
South America 19.600, -114.873 -70.225, -25.049
Mediterranean 69.873, -34.014 -19.951, 55.811
India 31.025, 10.811 -58.799, 100.635
Japan 66.812, 89.912 -23.643, 179.736
Australia 16.963, 89.912 -72.861, 179.736
The archive of CZCS data products began on November 2, 1978
and continued until June 22, l986. However, there are several
periods of intermittent coverage. When operating full time,
approximately 400 Level 1 images were collected each month.
In total, over 60,000 Level 1 files were collected during the
lifetime of the CZCS instrument. 92 Level 3 global monthly
composites were ultimately created from these files. The
following figure shows a graphical display of the temporal
distribution of the original CZCS Level 1 data set that was
used to create the Level 3 products described in this
document.
Each CZCS scan viewed the Earth for approximately 27.5
microseconds. During this period, each channel of the analog
data output was digitized to obtain a total of about 2000
samples. Successive scans occured at the rate of 8 per
second. Subsequent coverage of the same geographic area
varied greatly from place to place and over the lifetime of
the instrument.
Level 3 data contains radiance data and photosynthetic
pigment concentration, the latter based on a spectral ratio
algorithm that utilized the geophysical parameters of
water-leaving radiance calculated for the 443, 520, and 550
nm bands. The raw radiance data collected by the CZCS was
atmospherically corrected for atmospheric and aerosol
scattering. The radiance data was correlated with pigment
concentration using the CZCS NET pigment algorithm and a
variety of calibration techniques. The calibration scheme had
to be revised during the mission due to both the failure of
active calibration and sensor degradation.
Level 3 pigment concentrations are expressed in units of
mg m^-3 with 18 km by 18 km resolution.
CZCS was flown aboard the Nimbus-7 satellite.
The CZCS level 3 data is converted from the DSP PST (Postage
Stamp) format into the DSP COMP format for display purposes.
DSP is a user-interactive satellite data analysis package
that was developed at the Rosenstiel School of Marine and
Atmospheric Sciences (University of Miami). DSP operates on
either DEC-VAX or Unix Workstation computers. The primary
application of this package is for the processing and
interpretation of CZCS and Advanced Very High Resolution
Radiometer (AVHRR) data. DSP images can be converted to the
SEAPAK format using the SEAPAK package (see description
below).
LEVEL 3 FLAT IMAGE FILE FORMAT
Several additional time/space composites (climatological,
seasonal, annual, regional) also exist as single parameter
images. These are available as flat data files, without any
headers, metadata or compositing statistics. These include
full resolution global 2048 (longitude) x 1024 (latitude)
pixel images as well as reduced resolution global 512 x 512
pixel images subsampled from the full global images with a 4
x 2 reduction factor. These regional images (spatial
coordinates tabulated in section 9 above) are 512 x 512 pixel
images at full resolution of the global product. They are
simply a sector of the full global 2048 x 1024 composite
grid. They are composed of 512 records, each record 512 eight
bit bytes and each pixel value given by a count ranging
between 0 and 255. Please consult the CZCS README file
available from the GSFC DAAC for further information on these
level 3 flat image files.
Other ocean color data sets include SeaWiFS, MOS-PRIRODA,
OCTS and some airborne data collected by NASA and NOAA. Many
investigations benefit from correlating CZCS data with
available in situ and sea surface temperature data.
More information is on our Satellite Based
Ocean Color Instruments page.
-
The greatest problems encountered in analyzing the CZCS
data are in the correction for atmospheric interference and
differentiating between chlorophyll concentrations and
suspended inorganic substances. In the visible portion of the
spectrum, the largest contribution to the signal received by
CZCS was from the atmosphere. Rayleigh and aerosol scattering
in the atmosphere must be compensated for before a high
degree of accuracy in the determination of pigment
concentration and diffuse attenuation coefficient can be
obtained.
The calibration procedure is quite complex and will not be
discussed in detail here. In essence, the Rayleigh component
is assumed constant and can be subtracted from the signal.
Aerosol scattering is variable and is measured by assuming
that the red region of the spectrum is completely absorbed by
the ocean surface and is therefore returning no signal to the
instrument. From this assumption, aerosol scattering can be
calculated for the rest of the visible spectrum. References
11.2.b and 11.2.c describe these principles in detail. The
final data are in the form of calibrated radiances.
Chlorophyll concentration algorithms were used to reduce
the data produced from the Level 1 radiance data to Level 2
pigment concentration imagery. These algorithms use radiance
data ratios to determine concentrations. Channels 1 and 3
were used for concentrations less than 1.5 mg/m**3 and
channels 2 and 3 for concentrations above that level. These
algorithms also account for the atmospheric scattering
present, both Rayleigh and aerosol, by empirical coefficients
in the equations for concentration. The Rayleigh component
was assumed constant and can be subtracted from the signal.
Aerosol scattering is variable and was measured by assuming
that the red region of the spectrum is completely absorbed by
the ocean surface and is therefore returning no signal to the
instrument.
At Goddard Space Flight Center the data were converted from
voltages to radiances for bands 1 through 5, and to
equivalent blackbody temperatures for band 6. The Level 1
radiance data were used to produce black and white images.
Algorithms developed by the CZCS Nimbus Experiment Team were
then applied to produce Level 1A and 2 data for pigments,
suspended particulates and dissolved substances in oceanic
waters. These algorithms have continued to evolve since the
beginning of data collection, especially for retrieval of
water properties in sediment-laden coastal regions.
The entire CZCS digital archive was later converted from the
original 1600-bpi magnetic tape to Sony digital optical disk
at Goddard Space Flight Center. 38,000 nine track magnetic
tapes were read 24 hours per day, 7 days per week for 18
months in order to transfer the data to approximately 185, 12
inch optical discs. The newly archived data format was nearly
identical to the Calibrated Radiance and Temperature Tape
(CRTT) product. These optical platters are now stored at the
Goddard DAAC and remain a primary archive for the CZCS data
set.
-
Some Level 1 scenes were flagged as containing unreliable
data and were not included in the Level 3 composites, but are
still available from the Goddard DAAC. During ingest into the
Goddard DAAC, metadata contained in the Level 1 files were
accessed and used to produce a comprehensive and consistent
database for all CZCS holdings. Many duplicate files and
errors were eliminated in this first effort. In 1996 the
metadata themselves were reviewed, uncovering several types
of navigational errors. Based on that analysis, the database
was updated and corrected again. The corrected database
entries now provide the framework for operational browse and
request processing.
In situ data useful for CZCS applications are available at:
http://disc.sci.gsfc.nasa.gov/oceancolor/dataprod/OC_Dataproducts.shtml.
SeaBASS is a product of the Calibration/Validation element of
the NASA Sea-viewing Wide Field-of-view Sensor (SeaWiFS)
Project. SeaBASS provides an interface to the Project's
holdings of bio-optical and laboratory instrument calibration
data. The interface allows access to over 1000 individual
data files provided by numerous investigators.
Currently, the SeaBASS bio-optical holdings include
radiometric data and in situ pigments collected as
part of these experiments:
Nimbus Experiment Team (NET)
U.S. Joint Global Ocean Flux Study (JGOFS)
CHORS_JGOFS
Bermuda Bio-Optical Program (BBOP)
CHORS/British Ocean Flux Study (BOFS)
Bermuda Area Time Series (BATS)
Hawaii Ocean Time Series (HOTS)
Tokyo Bay
MOCE1
MOCE2
MOCE3
CALCOFI Cruises
LTER
NORTH SEA Experiments
Chesapeake Bay
SeaBASS also includes instrument calibration data
collected as part of SIRREX-1, SIRREX-2, and eventually
SIRREX-3/4/5. New data sets are received and archived on a
regular basis. SeaBASS is described in much greater detail in
Volume 20 of the SeaWiFS Technical Report Series (NASA Tech.
Memorandum 104566). You may request a copy of Vol. 20 via the
SeaWiFS TM Series order form from the Goddard DAAC Helpdesk
via email or phone:help-disc@listserv.gsfc.nasa.gov,
(301) 614-5224.
CZCS performed better than its design requirements for
signal-to-noise ratio in all channels. The table below shows
the minimum signal-to-noise ratio specified for the
instrument at its most sensitive gain setting. In the worst
case, the chlorophyll concentration can be determined within
a factor of 2 of the actual concentration.
Channel/ Signal/Noise
Band Ratio (mW/cm**2-ster) Radiance NETD Temp
1 150 5.41
2 140 3.50
3 125 2.86
4 100 1.34
5 100 10.8
6 N/A N/A 0.220K 270K
No additional measurement error assessments are available.
No additional quality assesments are available.
The Goddard DAAC has not performed data verification on the
CZCS dataset. Only metadata verification has been performed.
-
The internal metadata in the header and trailer documentation
records for Level 1 files is known to be erroneous in several
instances. The Goddard DAAC's database has been corrected,
but the individual header and trailer records have not been
corrected.
Several assumptions in the atmospheric correction of the data
during data processing resulted in an accuracy of 35% in
ocean color measurements in Case 1 waters (chlorophyll and
associated pigments determine the reflectance), and within a
factor of 2 generally.
Due to the limited duty cycle (10%) and the non-uniform
coverage, sampling was highly skewed. Temporal sampling
frequency also varied, resulting in potential errors. An
in-depth overview of the entire history of the CZCS Project
is included in Reference 4 below.
(Please refer to Section 4.)
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is scheduled
to launch in 1997 as a follow-on to CZCS. SeaWiFS data will be
distributed to authorized users by the Goddard DAAC. Numerous
documents describing SeaWiFs data and the SeaWiFS Project
activities may be obtained from the The Ocean Color Data and
Resources website at
http://disc.sci.gsfc.nasa.gov/oceancolor/index.shtml
Users should refer to the SeaWiFS Project homepage for the
latest information on SeaWiFS:
http://seawifs.gsfc.nasa.gov.
- "CZCS Sensor Guide
Document", prepared by the Distributed Active Archive Center,
NASA Goddard Space Flight Center, Greenbelt, Maryland, 1995.
- "Ocean Color From Space",
Prepared by the US Global Ocean Flux Study Office with
contributions from NASA Goddard Space Flight Center, Wood's Hole
Oceanographic Institution, the University of Miami and
theUniversity of Rhode Island. HTML version published by the
Distributed Active Archive Center, NASA Goddard Space Flight
Center, Greenbelt, Maryland, 1995.
- "The Living Ocean: Observing Ocean Color From Space", NASA
Publication PAM-554, Goddard Space Flight Center, Greenbelt,
Maryland, 1993.
- "Coastal zone color scanner 'system calibration': A
retrospective examination." R.H. Evans & H.R. Gordon,
Journal of Geophysical Research, Vol.99. No. C4,
pages 7293-7307, April 15, 1994.
-
"Coastal Zone Color Scanner", European Space Research
Institute, Frascati, Italy.
- Nimbus 7 Coastal Zone Color Scanner (CZCS) Level 1 Data
Product Users' Guide NASA TM 86203, S.P. Williams, E.F.
Szajna and W.A. Hovis. Goddard Space Flight Center, Greenbelt, MD
20771. July, 1986, 53 pages.
-
The April 15, 1994 issue of the Journal of Geophysical
Research (Volume 99, Number C4) contains a Special
Section entitled "Ocean Color From Space: A Coastal Zone
Color Scanner Retrospective." Additional CZCS and
ocean color references are listed on the Goddard DAAC Ocean Color
Website.
-
The Goddard DAAC provides a mirror site for the distribution
of SEAPAK CZCS data processing software. We have also written a
read program to help users get started with analysis of Level 1
CZCS data. Below are the software descriptions and ftp links to
the software.
CZCS Level 1 Read Program
The level 1 CZCS data product is stored as raw binary
data. The program we have written will dump selected data
fields from selected data records found in a CZCS Level 1
data file. It will also dump selected data fields from the
documentation records which precede and follow the data
records.
CZCS_L1_SW
PC-SEAPAK
SEAPAK is a user-interactive satellite data analysis
package that was developed at the NASA/Goddard Space Flight
Center. The primary application of SEAPAK is for the
processing and interpretation of Level 1 Coastal Zone Color
Scanner (CZCS) and Advanced Very High Resolution Radiometer
(AVHRR) data. In addition, CZCS Level 1A and 2 DSP images can
be converted to the SEAPAK format using the SEAPAK package.
(DSP is image processing software developed at the Rosenstiel
School of Marine and Atmospheric Sciences of the University
of Miami.)
Two versions of the SEAPAK CZCS processing software are
available free of charge online and on tape from the Goddard
DAAC. PC-SEAPAK runs on PC-AT, 386, or 486 class machines.
UNIX-SEAPAK operates only on SGI's Unix Workstation. Besides
including most major programs in PC-SEAPAK to process CZCS
and AVHRR satellite data, Unix-SEAPAK also includes programs
to handle ancillary data.
Note: The DAAC is a mirror site to
shark.gsfc.nasa.gov. We do not support the maintenance and
development of SEAPAK. We will provide timely updates and
information to directly contact the authors.
PC-SEAPAK runs on PC-AT, 386, or 486 class machines.
UNIX-SEAPAK operates on SGI Unix Workstations only.
To be able to use all of PC-SEAPAK's graphics functions,
you will need to have a Matrox graphics board installed on
your PC. Even if you do not have this board, the whole
PC-SEAPAK package should be installed. It will work on a PC
without the board but the you won't be able to run the
display related programs. To request a non-graphical version
of PC-SEAPAK on diskettes, contact the Goddard DAAC Helpdesk:
help-disc@listserv.gsfc.nasa.gov.
Copies of the 350 page PC-SEAPAK User's Guide are available
online and in hardcopy from the Goddard DAAC Helpdesk. This
documentation is intended to be used by both UNIX and PC
customers and it is the only SEAPAK documentation available
from the Goddard DAAC.
PC-SEAPAK
User Guide
-
PC-SEAPAK
-
The PC version of SEAPAK is available through FTP.
PC-SEAPAK directory
In this directory, you will find four compressed files
and one program to decompress those files as well as
three update files:
- seapak.zip
- The compressed file that contains all the PC-SEAPAK
version 4.0 programs data base file (in 5-minute
resolution)
- ciadb.zip
- The compressed file that contains the eight CIA
world data base files.
- pctoms.zip
- The compressed file that contains nine PCTOMS data
base files.
- halo88.zip
- The compressed file that contains HALO88 font files
and the driver program for the MVP-AT image board
- pkunzip.exe
- The decompressing program to be used on PC to
decompress those compressed zip files.
These update files have to be restored (in any
temporary directory using 'pkunzip') and installed
(copied) IN ORDER into the SEAPAK directory after you
have installed the original PC-SEAPAK 4.0.
- update.zip
- update1.zip
- update2.zip
Download all of these files to the PC first. Then run
PKUNZIP to decompress all the ZIP files. Type PKUNZIP at
the DOS prompt and you will get a detailed description
about how to use this command.
For example, to decompress all files in 'SEAPAK.ZIP'
to the directory 'D:\SEAPAK', just type 'PKUNZIP
SEAPAK.ZIP D:\SEAPAK'. All other compressed files should
be decompressed the same way. It is recommended that you
decompress different zip files into different
directories. After all compressed files are restored, you
need set up the SEAPAK environmental variable, modify
SEAPAK.FIG file if necessary, run the programs SPKSETUP
and INIT.
For further information, read SYSTEM ENVIRONMENT:
SOFTWARE section in the PC-SEAPAK User's Guide.
-
UNIX-SEAPAK
-
The UNIX version of SEAPAK is available through FTP.
UNIX-SEAPAK directory
The files 'ANNOUNCEMENT', 'README.SEAPAK.PLEASE!' in
the UNIX SEAPAK directory contain information about how
to install UNIX-SEAPAK. Because there is no UNIX-SEAPAK
User's Guide available, UNIX SEAPAK users should request
a copy of the PC-SEAPAK User's Guide from the Goddard
DAAC Helpdesk: help-disc@listserv.gsfc.nasa.gov.
If you have any problem or need assistance with
installing or using SEAPAK, contact:
Gary Fu
301-286-7107
email: gfu@shark.gsfc.nasa.gov
For more information on scientific applications of the
SEAPAK and DSP image processing systems contact:
SEAPAK:
Dr. Charles McClain
SeaWiFS Project Scientist
email: mcclain@calval.gsfc.nasa.gov
DSP:
Dr. Robert Evans,
University of Miami's Rosenstiel School of Marine
Sciences
email: bob@ARWIN.rsmas.miami.edu
-
Goddard DAAC Ocean
Color Data and Resources Website
Goddard DAAC
Helpdesk
Code 610.2
NASA Goddard Space Flight Center
Greenbelt MD 20771 USA
help-disc@listserv.gsfc.nasa.gov
(301) 614-5224
(301) 614-5268 fax
NASA Goddard Space Flight Center
DAAC
The Goddard DAAC is the central archive and distribution
facility responsible for providing access to the entire CZCS
data set. The entire collection of Coastal Zone Color Scanner
(CZCS) ocean color data and images is available on-line via
the World Wide Web in the Data Section of the NASA Goddard
DAAC Ocean Color Data and Resources Website at
http://disc.sci.gsfc.nasa.gov/oceancolor/
Archive of the CZCS data set at the Goddard DAAC is
complete. Ocean Color website documentation and access
development is also nearing completion. Future activities will
be dedicated to the support of SeaWiFs archive and distribution
starting in calendar year 1997.
-
8mm tape (8200 and 8500 bpi)
4mm tape (60m and 90m)
electronic transfer (ftp)
- Calibration: the adjustment or systematic
standardization of the output of a quantitative measuring instrument or
sensor.
Chlorophyll: any of a group of related green pigments
found in photosynthetic organisms.
Contemporaneous: originating, existing, or occurring
during the same interval of time.
Dynamic Range: the range between the maximum and
minimum amount of input radiant energy that an instrument can measure.
Gelbstoffe: particulate matter, usually outflow
sediment from rivers, which, when suspended in water, gives it a
yellowish color. (from German: "yellow substance").
Infrared Light: electromagnetic radiation having
wavelengths longer than red light (7700 angstroms) but less than radio
waves (~.1 meter).
Nadir: the point on the Earth directly below an
orbiting satellite.
Photosynthesis: the process by which
chlorophyll-containing cells in green plants convert incident light to
chemical energy and synthesize organic compounds from inorganic
compounds, especially carbohydrates from carbon dioxide and water, with
the simultaneous release of oxygen.
Phytoplankton: drifting, often microscopic oceanic
plants which conduct the process of photosynthesis.
Primary productivity: the rate at which photosynthesis
proceeds.
Radiometer: a device that detects and measures
electromagnetic radiation.
Spatial Resolution: the size of the smallest object
recognizable using the detector.
Spectral Band: a narrow range of the electromagnetic
spectrum.
Spectral Response: the relative amplitude of the
response of a detector vs. the frequency of incident electromagnetic
radiation.
Visible Light: electromagnetic radiation with
wavelength in the 3900 to 7700 angstrom range.
- AVHRR: Advanced Very High Resolution Radiometer
CZCS: Coastal Zone Color Scanner
DST: Data Support Team
EOSDIS: Earth Observing System Data and Information
System
ESDIS: EOSDIS Data and Information System
ESRIN: European Space Research Institute
IFOV: Instaneous Field of View
MODIS: Moderate Resolution Imaging Spectroradiometer
Nimbus: NASA Meteorological Satellites (1 through 7)
[not an acronym]
NOAA: National Oceanic and Atmospheric Administration.
SeaWiFS: Sea-viewing Wide Field-of-view Sensor
Change History
- Version 2.0
- Version baselined on addition to the GES Controlled Documents List,
April 15, 1998.
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