BOREAS RSS-14 Level-1a GOES-8 Visible, IR, and Water-Vapor Images

Summary

The BOREAS RSS-14 team collected and processed several GOES-7 and GOES-8 image 
data sets that covered the BOREAS study region.  The level-1a GOES-8 images were 
created by BORIS personnel from the level-1 images delivered by FSU personnel. 
The data cover 14-Jul-1995 to 21-Sep-1995 and 12-Feb-1996 to 03-Oct-1996.  The 
data start out as three bands with 8-bit pixel values and end up as five bands 
with 10-bit pixel values.  No major problems with the data have been identified.  
The differences between the level-1 and level-1a GOES-8 data are the formatting 
and packaging of the data.  The images missing from the temporal series of 
level-1 GOES-8 images were zero-filled by BORIS staff to create files consistent 
in size and format.  In addition, BORIS staff packaged all the images of a given 
type from a given day into a single file, removed the header information from 
the individual level-1 files, and placed it into a single descriptive ASCII 
header file.  The data are contained in binary image format files.

Table of Contents

   *  1 Data Set Overview
   *  2 Investigator(s)
   *  3 Theory of Measurements
   *  4 Equipment
   *  5 Data Acquisition Methods
   *  6 Observations
   *  7 Data Description
   *  8 Data Organization
   *  9 Data Manipulations
   *  10 Errors
   *  11 Notes
   *  12 Application of the Data Set
   *  13 Future Modifications and Plans
   *  14 Software
   *  15 Data Access
   *  16 Output Products and Availability
   *  17 References
   *  18 Glossary of Terms
   *  19 List of Acronyms
   *  20 Document Information

1. Data Set Overview

1.1 Data Set Identification

BOREAS RSS-14 Level-1a GOES-8 Visible, IR, and Water-Vapor Images

1.2 Data Set Introduction

For the BOReal Ecosystem-Atmosphere Study (BOREAS), the level-1a Geostationary 
Operational Environmental Satellite 8 (GOES-8) imagery, along with the other 
remotely sensed images, was collected in order to provide spatially extensive 
information over the primary study areas at varying spatial scales.  The GOES-8 
data set has a significant improvement in spatial resolution over the GOES-7 
data from 1994 and early 1995.

1.3 Objective/Purpose

The primary objective for the GOES-8 images in 1995 and 1996 was to collect 
visible, infrared (IR) and water-vapor channel data covering the BOREAS region 
at a sufficiently high temporal frequency for subsequent use in analyzing 
weather events and deriving temporal surface radiation parameters and patterns 
that existed during the Focused Field Campaign (FFC) and Intensive Field 
Campaign (IFC).

1.4 Summary of Parameters

The level-1a GOES-8 data from 1995 and 1996 in the BOREAS Information System 
(BORIS) contains the following parameters:

Image header and summary information; central geographic position; digital 
counts for half-hourly visible and IR images; latitude and longitude coordinate 
reference files. The level-1a GOES-8 data set starts out as a 3- band 8-bit data 
set in 1995 and changes to a 5- band 10-bit data set in 1996.  The image sizes 
varied in 1995 as well but stabilized in 1996.

1.5 Discussion

Dr. Eric Smith Florida State University (FSU) provided BORIS with the level-1 
GOES-8 images that were used to create the level-1a products.  BORIS staff 
processed the level-1a GOES-8 images by: 1) summarizing and extracting header 
information from the level-1 GOES-8 images and and placing it in an American 
Standard Code for Information Interchange (ASCII) file on disk, 2) reviewing the 
header file information for potential errors, 3) working with FSU personnel to 
remove erroneous files detected in step 2, 4) repackaging/reformatting the image 
data for a given day, 5) writing the reformatted data files to tape, and 6) 
loading the on line data base with needed information.

1.6 Related Data Sets

BOREAS Level-1 GOES-7 Images from 1994 and 1995

BOREAS Level-1a GOES-7 Images from 1994 and 1995

BOREAS Level-2 GOES-7 1994 Surface Radiation Data

BOREAS Level-1 GOES-8 Images from 1995 and 1996

2. Investigator(s)

2.1 Investigator(s) Name and Title

2.2 Title of Investigation

GOES Imagery for the BOREAS Experimental Areas 

2.3 Contact Information

Contact 1
---------
Jeffrey A. Newcomer
Raytheon STX Corporation
NASA GSFC
Greenbelt, MD  
(301) 286-7858
(301) 286-0239 (fax)
Jeffrey.Newcomer@gsfc.nasa.gov

Contact 2
---------
Dr. Eric A. Smith         
Florida State University  
Tallahassee, FL
(904) 644-4253            
(904) 644-9639 (fax)            
esmith@metsat.met.fsu.edu 

3. Theory of Measurements

The mission of the GOES satellite series is to provide the nearly continuous, 
repetitive observations that are needed to predict, detect, and track severe 
weather.  GOES spacecraft are equipped to observe and measure cloud cover, 
surface conditions, snow and ice cover, surface temperatures, and the vertical 
distributions of atmospheric temperature and humidity.  They are also 
instrumented to measure solar X-rays and other energetics, collect and relay 
environmental data from platforms, and broadcast instrument data and 
environmental information products to ground stations.  The GOES system includes 
the satellite (with the GOES instrumentation and direct downlink data 
transmission capability); the National Environmental Satellite, Data and 
Information Service (NESDIS) facility at Wallops Island, VA; and the ground 
systems at NESDIS.

4. Equipment

4.1 Sensor/Instrument Description (GOES-8)

The GOES I-M imager on the GOES-8 satellite is a five-channel (one visible, four 
IR) imaging radiometer for measuring radiant and reflected energy from Earth.  
Using a servo-driven, two-axis gimbaled mirror scan system with a Cassegrain 
telescope, the multispectral channels simultaneously sweep an 8-km (5-statute-
mile) north-to-south swath along an east-to-west/west-to-east path, at a rate of 
20 degrees east-west per second.

The imager consists of electronics, power supply, and sensor modules.  The 
sensor module containing the telescope, scan assembly, and detectors is mounted 
on a base plate external to the spacecraft, together with the shields and 
louvers for thermal control.  The electronics module provides redundant 
circuitry and performs command, control, and signal processing functions; it 
also serves as a structure for mounting and interconnecting the electronic 
boards for proper heat dissipation.  The power supply module contains the 
converters, fuses, and power control for interfacing with the spacecraft 
electrical power subsystem.  The electronics and power supply modules are 
mounted on the spacecraft internal equipment panel.

--------------------------------------------------------------------------------
Imager Instrument Characteristics               Spectral  Bands  (micrometers)

                                    VIS     IR2     IR3    IR4     IR5
--------------------------------------------------------------------------------
Wavelength (micrometers)             0.55   3.80    6.50   10.20   11.50
                                      to     to      to      to      to
                                     0.75   4.00    7.00   11.20   12.50
--------------------------------------------------------------------------------
Clouds                               X       X       X      X       X
--------------------------------------------------------------------------------
Water Vapor                                          X      X       X
--------------------------------------------------------------------------------
Surface Temp                                 0              X       0
--------------------------------------------------------------------------------
Winds                                X               X      X
--------------------------------------------------------------------------------
Albedo & IR Flux                     X               0      X       0
--------------------------------------------------------------------------------
Fires & Smoke                        X       X              0       0
--------------------------------------------------------------------------------
X:  Primary Spectral Channel
0:  Secondary (supplementary) Spectral Channel
--------------------------------------------------------------------------------
Field of View Defining Element:  Detector
--------------------------------------------------------------------------------
Optical Field of View:           Square
--------------------------------------------------------------------------------
5-channel Imaging:               Simultaneously
--------------------------------------------------------------------------------
Scan Capability:                 Full Earth/Sector/Area
--------------------------------------------------------------------------------
Channel/Detector                 Instantaneous Field of View (IFOV)
  Visible/Silicon                : 1 km
  Short-wave/InSb                : 4 km
  Moisture/HgCdTe                : 8 km
  Long-wave 1/HgCdTe             : 4 km
  Long-wave 2/HgCdTe             : 4 km
--------------------------------------------------------------------------------
Radiometric Calibration:  Space and 290 Kelvin IR internal blackbody
--------------------------------------------------------------------------------
Signal Quantizing (NEdeltaT)   : 10 bits all channels
  S/N                            : Minimum 3X better than specifications
--------------------------------------------------------------------------------
Frequency of Calibration Space   : 2.2 sec for full disk;
                                 : 9.2 or 36.6 sec for sector/area
Infrared                         : 30 minutes typical
--------------------------------------------------------------------------------
System Absolute Accuracy         : IR channel less than 0.1 K
--------------------------------------------------------------------------------
Transmit Frequency               : 1676.00 MHz
--------------------------------------------------------------------------------

4.1.1 Collection Environment

The GOES-8 data were acquired using the FSU Direct Readout Ground System located 
in Tallahassee, FL, starting on 14-Jul-1995 and continuing through 23-Oct-1996.

The GOES-8 satellite orbited Earth in a geostationary orbit at an altitude of 
35,788 km (19,324 nautical miles).

4.1.2 Source/Platform

Launch and data available dates for the GOES-8 satellite are:

Satellite    Launch Date                 Data Range
---------    -----------            -----------------------
GOES-8       13-Apr-1994                 0-1024

4.1.3 Source/Platform Mission Objectives

The mission of the GOES satellite series is to provide the nearly continuous 
observations that are needed to predict, detect, and track severe weather.  GOES 
spacecraft are equipped to observe and measure cloud cover, surface conditions, 
snow and ice cover, surface temperatures, and the vertical distributions of 
atmospheric temperature and humidity.  They are also instrumented to measure 
solar X-rays and other energetics, collect and relay environmental data from 
platforms, and broadcast instrument data and environmental information products 
to ground stations.

For BOREAS, the level-1 GOES-8 imagery, along with the other remotely sensed 
images, was collected in order to provide spatially extensive information over 
the primary study areas at varying spatial scales.  The primary objective for 
the GOES-8 images in 1995 and 1996 was to collect visible, IR and water-vapor 
channel data covering the BOREAS region at a sufficiently high temporal 
frequency for subsequent use in analyzing weather events and deriving temporal 
surface radiation parameters and patterns that existed during the FFC and IFC.  
The GOES-8 data set has a significant improvement in spatial resolution over the 
GOES-7 data from 1994 and early 1995.

4.1.4 Key Variables

Reflected radiation
Emitted radiation
Water vapor

4.1.5 Principles of Operation

The GOES I-M program is a continuation of the previous National Oceanic and 
Atmospheric Administration (NOAA) National Aeronautics and Space Administration 
(NASA) collaboration to provide continuous monitoring of Earth's environment for 
weather forecasting and research.  The objectives of the GOES I-M program are to 
maintain and expand the operational, environmental, and storm warning 
capabilities; to monitor Earth's atmosphere and surface and space environmental 
conditions; and to introduce improved atmospheric and oceanic observations and 
data dissemination capabilities.

GOES I-M is a new series of five satellites that meet these objectives, 
providing significant improvements in weather imagery and atmospheric sounding 
information in accordance with current weather service requirements, 
particularly in regard to the forecasting of life-and property-threatening 
severe storms.  A novel space-and ground-based computer and communication system 
provides users with calibrated and navigated (i.e., Earth-located) imagery and 
sounding data, in real time.

The GOES I-M spacecraft meet the missions objectives by providing:

  Independent imaging and sounding functions with instrument resolution,
   navigation, channelization, and signal-to-noise characteristics representing
   improvements over previous GOES missions

  Full-time Weather Facsimile Transmission

  Data Collection System Transponder Functions

  Space Environment Monitor System

  Search and Rescue Transponder Functions

These functions have resulted directly from the overall system requirements 
developed by NOAA and NASA together with the National Weather Service (NWS), the 
systems primary user.  Many of the requirements are continued missions from the 
previous GOES D-H series of spacecraft.  However, technological advancements 
have provided significant improvements in the reliability and availability of 
these systems for the new GOES I-M series.

As in the previous GOES mission, the GOES I-M system provides the above services 
over a region covering the central and eastern Pacific Ocean, the 48 contiguous 
States, and the central and western Atlantic Ocean.  This is accomplished by two 
satellites, GOES West located at 135 degrees west and GOES East (GOES-8 in this 
case) at 75 degrees west.  A common ground station, the Command and Data 
Acquisition (CDA) station located at Wallops Island, VA, services both 
satellites.

The GOES I-M Imaging and Sounding instruments provide significantly improved 
measurement capability over the previous GOES sensors.  The GOES I-M five-
channel Imager processes higher spatial resolution (i.e., 4 km for its IR 
channels) and higher radiometric sensitivity to improve the measurement of cloud 
and Earth's surface features.  Sounding quality is improved by having more 
spectral channels (18 IR and 1 visible) with greatly improved radiometric 
sensitivity.  The three-axis stabilized platform enables higher quality imagery 
and sounding data to be achieved through its dwell time advantage over a 
spinning satellite.  The flexibility of scan control by both instruments 
combined with the three-axis stability enables rapid small-area coverage in 
addition to hemispheric or full-disk coverage.  The new limited-area, higher 
frequency observation capability permits more continuous monitoring of severe 
weather development.






The flexible nature of the Imager is used to provide a star-sensing capability.  
Time and location of a star is predicted very accurately and related to the 
spacecraft location and optical field.  From a set of these data, the ground 
control system chooses a location and a time that is convenient within the 
imaging schedule.  At the time for the scheduled starlook, the Imager is pointed 
to the predicted star location, which can be anywhere within its 21 degrees N-S 
by 23 degrees E-W view.  (These viewing limits are for star sensing only.  The 
maximum frame size during normal imaging operations is 19 degrees N-S by 19.2 
degrees E-W).  As the star passes through one or two of the eight elements of 
the visible array, it is sampled for Instrument Navigation & Registration (INR) 
purposes.  The data is in the normal format and data stream for extraction and 
use at the ground station.

The GOES I-M generation of spacecraft has been developed by the Space 
Systems/Loral, Inc. (SS/L).  These satellites are three-axis body stabilized, 
meaning that the three axes of the satellite remain stationary relative to 
nadir.  These satellites use internal momentum wheels to provide attitude 
control and require corrective action from the ground to compensate for the 
effects of thermal gradients and solar winds.  Unlike the previous GOES D-H 
series, the GOES I-M spacecrafts Imaging and Sounding instruments can be 
operated simultaneously and independently of one another.

The spacecrafts configuration is essentially a compact six-sided main body that 
carries the operational instruments, a continuous drive solar array attached to 
the south panel through a yoke assembly, a solar sail mounted off the north 
panel to offset solar pressure torque, a Telemetry and Command (T&C) antenna 
boom-mounted on the east end for full omni-directional coverage, and the Space 
Environmental Monitoring (SEM) magnetometer on a boom off the anti-Earth side of 
the satellite.

The main body of the spacecraft accommodates the 5-channel visible and IR Imager 
and the 19-channel visible and IR Sounder, which sample radiance from Earth by 
identical two-axis scan systems and nearly identical telescopes in each unit.  
Scan control and data collection for the instruments are independent of each 
other and of most other activity on the spacecraft.


4.1.6 Sensor/Instrument Measurement Geometry

During data acquisition for BOREAS, the GOES-8 satellite was stationed at 
approximately 0.0 degrees N, 75.0 degrees W.

The Imager is a multi-channel instrument designed to sense radiant and solar-
reflected energy from sampled areas of Earth's surface and atmosphere.

The Imagers multi-element spectral channels simultaneously sweep an 8-km north-
south (N-S) (longitudinal) swath along an east-west (E-W) (latitudinal) path by 
means of a two-axis gimbaled mirror scan system.  Position and size of an area 
scan are controlled by command.  Beam splitters separate the spectral channels 
to the various IR detector sets, which are redundant.  The 1-by-8 km visible 
detector array consisting of eight individual detectors is not redundant.

Radiometric quality of the Imager is maintained by frequent views of space for 
Dark Current (DC) signal restoration.  Less frequent views of the full aperture 
black-body (BB) establish a high temperature calibration point that determines 
the radiometric conversion factor for the IR channels.  The frequency of 
radiometric calibration depends on the thermal and electrical stability of the 
system.  In addition to radiometric calibration, the amplifiers and data stream 
are checked regularly from a 16-increment electronic calibration signal.  This 
verifies the stability and linearity of the output data.

Control of the Imager comes from a defined set of command inputs.  The 
instrument is capable of full Earth imagery, sector imagery that contains the 
edges of Earth, and various sizes of area scans totally enclosed within the 
Earth scene.  Area scan selection permits rapid, continuous viewing of local 
areas for monitoring of mesoscale phenomena and accurate wind determination.  
Area scan size and location are definable to less than one visible pixel to 
provide complete flexibility.


Motion of the Imager and Sounder scan mirrors causes a small but well-defined 
disturbance of the spacecraft attitude.  This effect is gradually reduced by 
spacecraft control but at a rate too slow for total compensation.  Since all the 
physical factors of the scanners and spacecraft are known and the scan positions 
are continuously provided to the Imager and Sounder, the disturbances caused by 
each scan motion on the spacecraft and distributed to each instrument are 
calculated by the Attitude and Orbit Control System (AOCS).  The Mirror Motion 
Compensation (MMC) signal is developed and used in the scan system server 
control loop to slightly modify the scan rate and position to offset the 
disturbance.  This simple signal and control interface provides corrections that 
reduce any combination of effects.  With this system in place, the Imager and 
Sounder are totally independent, maintaining image location accuracy regardless 
of the other units operational status.  If need be, this MMC scheme can be 
disabled by command.

The AOCS also provides an Image Motion Compensation (IMC) signal that 
counteracts the spacecraft attitude, orbit effects, and predictable structural-
thermal effects within the spacecraft-instrument combination.  These effects are 
detected from ranging, star sensing, and landmark features.  Corrective 
algorithms developed on the ground are fed through the AOCS to the instruments 
as a total IMC signal, which includes the MMC described above.

Signal flow through the Imager maintains the maximum capability of each part of 
the optics, detection, and electronic subsystems to preserve the quality and 
accuracy of the sensed information.  The signal flow starts with the radiation 
collected from the scene by the instruments optical system.  This scene 
radiance is separated into appropriate spectral channels and imaged onto the 
respective detectors for each channel.  Each detector converts the scene 
radiance into an electrical signal that is amplified, filtered, digitized, and 
put into a data stream for transmission to a ground station.

The sensor assembly is mounted on a base plate external to the spacecraft, 
together with shields and louvers for radiation and heat control.  The 
electronics module provides a structure for mounting and interconnecting the 
electronic boards with proper heat dissipation.

The sensor assembly contains the telescope, scan assembly, and detectors.  A 
passive radiant cooler with a thermostatically controlled heater maintains the 
IR detector temperature for efficient operation. The IR detectors operate at 
three patch temperatures:  94 K for 7 or 8 months that include the winter 
season, 101 K for the 4 or 5 months that include the summer season, and 104 K 
for radiative cooler contingencies.  The visible detectors are at temperatures 
of 13 degrees C to 30 degrees C.  Preamplifiers in the sensor assembly convert 
the low-level signals to higher level, low-impedance outputs for transmission by 
cable to the electronics module.  A passive louver assembly and electrical 
heaters on the base aid thermal stability of the telescope and major components.

The Imager instrument acquires radiometric data simultaneously for five distinct 
channels.  These five radiometric channels are characterized by a central 
wavelength denoting primary spectral sensitivity within these channels.  The 
five channels are split into two distinct classes, visible and IR, and comprise 
a total of 22 detectors as follows:

  Visible-Channel 1 of the Imager contains eight visible detectors arranged in
   a linear fashion (v1-v8).  Each detector provides an Instantaneous Geometric
   Field of View (IGFOV) of 28 microradians on a side.  At the subsatellite
   point, this corresponds to a square pixel of 1 km per side.

  IR-Channel 3 (6.75 m) contains two square detectors, one primary and one
   redundant.  Each provides an IGFOV of 224 microradians corresponding to an
   8-km resolution at the subsatellite point.

  IR Channels 2 (3.9 m), 4 (10.7 m), and 5 (12.0 m) each contain four
   detectors:  two of these are the primary detectors and the other two provide
   redundancy.  Each of these detectors is square, providing an IGFOV of 112
   microradians.  At the subsatellite point, this corresponds to a square pixel
   having dimensions of 4 km per side.

The Imager scans the selected image area in alternate directions on alternate 
lines.  The imaging area is defined by a coordinate system related to the 
instruments orthogonal scan axis.  During imaging operations a scan line is 
generated by rotating the scanning mirror in the E-W direction while 
concurrently sampling each of the active imaging detectors.  At the end of the 
line, the Imager scan mirror performs a turnaround, which involves stepping the 
mirror to the next scan line and reversing the direction of the mirror.  The 
next scan line is then acquired by rotating the scanning mirror in the opposite, 
west-east direction, again with concurrent detector sampling.  Detector sampling 
occurs within the context of a repeating data block format.  In general, all 
visible detectors are sampled four times for each data block (four times 1 km 
wide), while each of the active IR detectors is sampled once per data block (one 
times 4 km wide).
 
4.1.7 Manufacturer of Sensor/Instrument

Aerospace/Communications Divisions of ITT
McLean, VA

4.2 Calibration

The calibration of the IR data and the normalization of the visible data are 
performed by the Operations Ground Equipment (OGE) on the raw data received from 
the spacecraft Imaging and Sounding sensors.  The calibration/normalization 
function can be described in terms of those functions that occur during online 
processing and those that are performed during non-real-time operating modes.

The real-time calibration and normalization of Imager and Sounder data can be 
divided into a continual application process and a periodic calibration 
coefficient generating process.  In the real-time continual application process, 
factory-measured detector response characteristics together with in-flight 
measurements made while viewing space and BB targets are used by the Sensor 
Processing Subsystem (SPS) to convert raw Imager and Sounder sensor data to 
theoretical target radiance.  All radiometric image data produced by the Imager 
and Sounder instruments must undergo calibration/normalization processing.  This 
function is performed in the SPS and involves the conversion of instrument 
output from raw digital counts to its final physical units.  For IR data 
calibration, this process uses the recalculated gain and bias factors to adjust 
for detector variations over time.  This calibration process takes place in the 
SPS.  The visible data normalization is performed so that all detectors of the 
same instrument produce the same readings when viewing an area of uniform 
brightness.  The data produced by the eight Imager visible channels must be 
normalized to prevent striping.  The normalization process is performed in the 
SPS with data provided by the Product Monitor (PM).  These data are generated by 
an operator performing a histogram matching using data with the full range of 
intensities.

The SPS maintains a current calibration data base for each satellite to be used 
in the real-time calibration of raw Imager and Sounder sensor data.  The data 
base is maintained for both primary and redundant detectors.  The SPS maintains 
the coefficients for the calibration equations that have been supplied to the 
data base prior to launch.  This factory detector response information consists 
of Imager and Sounder IR nominal coefficients.  The SPS data base has the 
equations for converting the BB thermistor output to temperature and BB 
temperature to equivalent target radiance.  In addition, the data base contains 
the current calibration coefficients for the IR channels, which are based on the 
space and BB measurements.  These calibration coefficients, computed by the SPS, 
are the gain and bias factors and coefficients of the quadratic terms.  They 
must be recalculated periodically because it is expected that these factors will 
vary with the age and temperature of the instruments.  This information is 
maintained, for both the Imager and Sounder, in a data base that resides in the 
SPS memory.

Normalization for Imager visible data is performed in real time by the Sensor 
Data Interface (SDI) hardware, through use of look-up tables.  For Imager and 
Sounder IR data, calibration is performed by the SPS software, using the 
calculated calibration coefficients.

Imager data are ingested into the SPS via the SDI as a serial bit stream.  
Following ingest processing, including bit and frame synchronization, the SDI 
hardware under SPS software control performs normalization of the visible data.  
The SDI hardware uses the radiometric look-up tables to normalize Imager visible 
data by compensating for variation in the satellite detector response curves 
over time.  The appropriate tables are loaded from the SPS memory into SDI 
hardware tables, under the control of the Imager Interface task.  These look-up 
tables are used by the SDI to locate the correct value for a detector pixel.  
There are different tables for each of the eight Imager visible detectors.  
These radiometric tables are loaded with values that have been adjusted to 
incorporate the latest normalization information.  Imager IR data are deposited 
in SPS memory without any linear transformations. Calibration is then performed 
by SPS software using the actual calibration equations for the IR detectors.  
Sounder data are deposited in the SPS memory by the SDI, following ingest 
processing.  The Sounder Data Formatter task calibrates Sounder IR data and 
normalizes visible data, in SPS software, using the actual calibration equations 
for the IR and look-up tables for the visible.

The periodic calibration coefficient generating process is performed to ensure 
that the best possible coefficient values are used when calibrating Imager and 
Sounder IR data.  This process allows for periodic recalculation of the 
coefficients contained in the calibration data base of the SPS.  Spacecraft 
instrument data are provided to the SPS in support of this operation.  This 
section defines the data received from the Imager and Sounder and their use in 
the detector calibration process.

The Imager and Sounder in the spacecraft perform periodic in-flight sequences 
that support IR calibration processing the OGE.  The instrument information 
generated includes space look, BB calibration, and Electronic Calibration 
(ECAL).

A space look sequence provides radiometric data for all detectors from a view of 
space located beyond the edge of Earth.  The Imager can perform space looks in 
two ways.  The instrument scan can be interrupted and the mirror pointed to 
space to take a reading; this is called a space clamp.  The frame can also be 
made such that either the left side or the right side extends beyond Earth's 
edge, beyond Earthshine, into space, making the instrument scan space; this is 
called a scan clamp.

In space clamp mode, the Imager performs a space clamp at the start of a frame 
with subsequent space clamps performed upon the execution of a timer.  The timer 
is selected at 9.2 seconds or 36.6 seconds; the timer restarts upon expiration 
so that space looks are at fixed intervals.  Upon timer expirations, the Imager 
completes the line it is scanning, slews horizontally to the preselected side to 
a point 10.2 from nadir to perform the space look, performs a turnaround 
sequence, and resumes scanning the frame.  The turnaround sequence includes 
retracing the last line three times, so the direction of the interruption is 
proportional to the width of the frame.  The total amount of time the scan is 
interrupted is proportional to the number of space looks performed, and 
therefore, to the total size of the frame.

In scan clamp mode, the frame scan is never interrupted, but the frame actually 
scanned extends out into space, beyond the area of meteorological interest.  The 
frame edge extends beyond Earth's edge, beyond Earthshine, a 0.5  wide ring 
around Earth, and out into space far enough to acquire a preset number of 
samples.  Initially, the number of samples obtained by the GOES-8 Imager will be 
400 IR samples, 64 microns on center, for a displacement of 1.47  beyond 
Earthshine.  Scan clamp mode will typically be used for full disk frames, making 
the frame boundary lie 1.97  beyond Earth's edge at the Equator, 10.67  from 
nadir.  In a full disk frame scanned thus, with the over scan into space applied 
only to one side of Earth, i.e., every other scan line, space calibration data 
are obtained every 2.2 seconds.

The Sounder operates in a space clamp mode similar to that of the Imager.  The 
Sounder space clamp mode is its only mode of operation.  A space look is 
performed by the Sounder every 2 minutes.  In normal and priority modes, after 
each location is sounded, a timer is examined to see if a space look is 
necessary.  The Sounder then saves the current address and slews to the space 
location.  Upon completion, the Sounder checks to determine if ECAL and BB 
calibration should be performed.  If not, the instrument returns to the original 
location.

A BB calibration consists of data samples from a view of the instruments 
internal BB.  Both space look and ECAL data are transmitted as part of the BB 
calibration operation.  The ECAL data generated are used by the PM to monitor 
linearity of the Imager and Sounder instruments electronic gain.  In the 
Imager, the BB calibration is normally performed every 20 minutes, unless doing 
so would mean interrupting an image in process.  At the most, the Imager may go 
30 minutes between BB views.  The BB calibration process does not interrupt any 
other operation and cannot occur during a frame.  The only exception to this is 
if a frame is interrupted by a priority scan frame or a star sense operation.  
The BB calibration may then be performed after the priority operation is 
completed and before returning to the interrupted frame.  When executing a BB 
calibration, the Imager outputs ECAL data, performs a space look operation, and 
then slews to the BB location to gather data.  It then returns to space and 
executes another space look.  In the Sounder, a BB calibration sequence is 
performed after every 20 minutes, unless inhibited by ground command.  The 
Sounder BB calibration operation consists of outputting samples of ECAL, after 
the space look samples, and slewing to a BB.  The scan mirror settles, then 
collects samples of BB target data prior to returning to the interrupted 
operation.  During normal sounding, a space look or a BB calibration operation 
is performed when its respective timer has expired and only after the current 
location has been sounded before the scan system steps to the next location.

For both the Imager and Sounder, the in-flight calibration data generated, 
together with the raw spacecraft sensor data, are transmitted to the SPS at the 
CDA for use in IR calibration processing.  The calibration data, ECAL, space 
look, and BB measurements are extracted for the Imager and Sounder data and used 
for calculation of the IR calibration equations.  After the data have been 
extracted, the SPS software verifies the data and performs out-of-limit checks 
prior to calculating calibration coefficients.  This process is performed in the 
instrument calibration preprocessing tasks.  Here the spacecraft calibration 
data from both the Imager and Sounder undergo statistical quality checks, limit 
checks, and verification.  The good data are then averaged into a single value 
for each detector or detector/filter combination.  The resulting space look and 
BB calibration data are received from the SPS memory and used by the calibration 
processing task to compute the needed coefficients.

The SPS provides normal mode (Mode 1) calibration for both the Imager and 
Sounder, along with a number of extended modes.  In the normal mode, the 
space look, BB, and BB temperature data resulting from the in-flight calibration 
sequences are used by the SPS to compute the gain and bias factors necessary for 
both Imager and Sounder IR calibration.  The coefficients of the quadratic 
calibration terms are extracted from a table of factory-measured coefficients 
versus instrument temperature.  These extended modes compensate for the effects 
of 1/f noise in the instruments as well as rapid changes in instrument and 
detector temperatures.

Upon completion of the real-time data processing, the SPS formats the calibrated 
infrared and normalized visible Imager and Sounder data into GOES VARiable 
(GVAR) processed data streams.  The newly computed IR calibration coefficients 
and the space look and BB statistics generated during their calculation are also 
included in GVAR for transmission to the OGE Performance Management System (PMS) 
and the user community.  The GVAR processed data consist of data blocks numbered 
0-11.  The calibrated and normalized Imager data are buffered by the SPS until 
space look occurs.  When a space look occurs, the SPS continues to buffer the 
Imager data until the end of the current scan line is reached.  The SPS then 
formats these data to be included in the GVAR blocks 0-10.  Following the 
transmissions of blocks 0-10 is the transmission of various block 11s.

During Sounder operation, block 11s containing the Sounder sensor data that have 
been calibrated and normalized by the SPS as well as the raw Sounder data are 
queued in the SPS for output.  Blocks containing the Imager and Sounder 
calibration statistics generated along with the IR coefficients and the visible 
Normalization Look-up Tables (NLUT) used in processing the instrument data are 
also queued for output, ordered according to their priority.

The non-real-time calibration/normalization functions include the generation of 
visible normalization coefficients and the production of short- and long-term 
history files of data and archive.  The visible NLUTs are used in the SPS for 
the normalization of Imager and Sounder visible data.  These NLUTs are generated 
periodically through an analyst-interactive histogram matching technique 
performed with the PM.  The PM provides the capability to analyze Imager and 
Sounder visible data statistically through normalization diagnostics.  These are 
performed to monitor the quality of the normalization of Imager and Sounder 
visible data and to provide a means to determine whether new tables are needed.  
To perform the diagnostic, a full-resolution normalized image sector, 
transferred in GVAR, is received by the PM equipment.  The operator selects a 
sector containing cloud cover, ocean, and land masses to maximize the dynamic 
range represented by the values.  The analyst displays and examines the image to 
see if it has desirable characteristics.  From the displayed image, the PM 
automatically generates histograms and cumulative (integrated) histograms of 
count levels for each channel and displays them along with associated 
statistics.  The analyst then selects a reference channel, based on long-term 
stability, and uses it as a basis with which to compare the remaining channels.  
The data generated as a result of the normalization diagnostic are available for 
storage, display, and printing.  The statistics are stored in a normalization 
history file maintained in the PM.  Selected plots may be displayed 
simultaneously with the reference detectors cumulative histogram for 
comparison.  In addition, the delta values that result from the comparison of 
cumulative histograms can be displayed along with the maximum deviation from the 
reference detector.  The analyst uses these statistics to determine the quality 
of the normalization performed on the visible image data and to determine 
whether a normalization update is warranted.

To generate new NLUTs, a raw visible data transmission from the SPS is 
scheduled.  This is done by disabling the normalization process in the SPS.  The 
data are received by the PM, where a high-resolution visible image sector is 
recorded and displayed to verify desirable characteristics.  From the displayed 
raw image data, cumulative histograms are automatically generated and displayed.  
A reference detector is selected for NLUT generation.  New NLUTs are then 
calculated for the other detectors by matching the target and the reference 
detectors cumulative histograms.  For each target detector count value, the 
percentile becomes the new NLUT value for the detector.  These new look-up 
tables are then applied to the raw image sector data, and the sector is 
displayed for review.  Cumulative histogram statistics are generated directly 
from all the visible detector data stored in a high-resolution image sector.  
These statistics can then be plotted for further review.  Once approved by the 
analyst, the newly generated NLUTs are sent to Orbit and Altitude Tracking 
Systme (OATS) and transmitted to the SPS, through GOES I-M Telemetry and Command 
System (GIMTACS), for use.

The level-1 GOES-8 images have not had any calibration applied.  Information on 
calibration procedures can be found at 
http://www.nnic.noaa.gov/SOCC/SOCC_Home.html.


4.2.1 Specifications

The level-1 GOES-8 images have not had any calibration applied.  Information on 
calibration procedures can be found at 
http://www.nnic.noaa.gov/SOCC/SOCC_Home.html.

5. Data Acquisition Methods

The BOREAS level-1 GOES-8 images used in the level-1a product creation were 
obtained by Dr. Eric Smith at FSU and supplied to BORIS. The data were acquired 
using the FSU Direct Readout Ground System located in Tallahassee, FL, starting 
on 14-Jul-1995 and continuing through 23-Oct-1996.

6. Observations

6.1 Data Notes

None.

6.2 Field Notes

Not applicable.

7. Data Description

7.1 Spatial Characteristics

The scanning system consists of a mirror that is stepped mechanically to provide 
north to south viewing, while the rotation of the GOES satellite provides west 
to east scanning.  The mirror is stepped following each west to east scan.  A 
sequence of 1,821 scans over 18.21 minutes is performed to provide a "full disk" 
view from just beyond the northern Earth horizon to just beyond the southern 
Earth horizon.

Based on the level-1 GOES-8 images, the BOREAS level-1a GOES-8 images 
essentially cover the entire 1,000-km by 1,000-km BOREAS region.  This contains 
the Northern Study Area (NSA), the Southern Study Area (SSA), the transect 
region between the SSA and NSA, and some surrounding area.

7.1.1 Spatial Coverage

The North American Datum of 1983 (NAD83) corner coordinates of the BOREAS region 
are:

             Latitude     Longitude
             --------     ---------
Northwest    58.979 N     111.000 W
Northeast    58.844 N      93.502 W
Southwest    51.000 N     111.000 W
Southeast    50.089 N      96.969 W


7.1.1.1 Spatial Coverage for GOES-8 Three-Band Data (14-Jul-1995 to 29-Jul-1995)

The corner latitude and longitude coordinates for the GOES-8 three-band data 
from 14-Jul-1995 to 29-Jul-1995 are shown in the following tables, where the 
value of -999.000 indicates that the sensor was viewing past the Earth horizon 
into outer space.

            Visible     Visible
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    73.054     -125.439
Southwest    45.774     -100.785
Southeast    45.323      -91.759

              IR4         IR4
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    73.117     -125.818
Southwest    45.823     -100.814
Southeast    45.372      -91.801

              IR3         IR3
           Latitude    Longitude
          ----------  -----------
Northwest  -999.999     -999.000
Northeast  -999.000     -999.000
Southwest    38.350      -97.267
Southeast    38.067      -89.634


7.1.1.2 Spatial Coverage for GOES-8 Three-Band Data (01-Aug-1995 to 21-Sep-1995)

The corner latitude and longitude coordinates for the GOES-8 three-band data 
from 01-Aug-1995 to 21-Sep-1995 are shown in the following tables, where the 
value of -999.000 indicates that the sensor was viewing past the Earth horizon 
into outer space.

            Visible     Visible
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    65.462      -98.345
Southwest    47.809     -107.113
Southeast    46.773      -87.996

              IR4         IR4
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    70.047     -104.477
Southwest    46.147     -105.839
Southeast    45.222      -87.592

              IR3         IR3
           Latitude    Longitude
          ----------  -----------
Northwest  -999.999     -999.000
Northeast  -999.000     -999.000
Southwest    38.546     -101.379
Southeast    37.971      -85.990


7.1.1.3 Spatial Coverage for GOES-8 Five-Band Data (12-Feb-1996 to 30-Apr-1996)

The corner latitude and longitude coordinates for the GOES-8 five-band data from 
01-Jan-1996 to 30-Apr-1996 are shown in the following tables, where the value of    
-999.000 indicates that the sensor was viewing past the Earth horizon into outer 
space.

            Visible     Visible
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    65.478      -98.187
Southwest    47.808     -107.162
Southeast    46.793      -88.137

              IR2         IR2
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    70.040     -104.087
Southwest    46.150     -105.913
Southeast    45.243      -87.745

              IR3         IR3
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast  -999.000     -999.000
Southwest    38.555     -101.528
Southeast    37.991      -86.186

              IR4         IR4
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    70.040     -104.087
Southwest    46.150     -105.913
Southeast    45.243      -87.745

              IR5         IR5
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    70.040     -104.087
Southwest    46.150     -105.913
Southeast    45.243      -87.745

7.1.1.4 Spatial Coverage for GOES-8 Five-Band Data (01-May-1996 to 03-Oct-1996)

The corner latitude and longitude coordinates for the GOES-8 five-band data from 
01-May-1996 to 03-Oct-1996 are shown in the following tables, where the value of 
-999.000 indicates that the sensor was viewing past the Earth horizon into outer 
space.

            Visible     Visible
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast   65.354       -96.453
Southwest   47.885      -108.274
Southeast   46.777       -87.385

              IR2         IR2
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    69.565      -99.365
Southwest    46.293     -108.022
Southeast    45.208      -86.229

              IR3         IR3
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast  -999.000     -999.000
Southwest    38.644     -103.275
Southeast    37.971      -84.902


              IR4         IR4
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    69.565      -99.365
Southwest    46.293     -108.022
Southeast    45.208      -86.229


              IR5         IR5
           Latitude    Longitude
          ----------  -----------
Northwest  -999.000     -999.000
Northeast    69.565      -99.365
Southwest    46.293     -108.022
Southeast    45.208      -86.229



7.1.2 Spatial Coverage Map

Not available at this time.

7.1.3 Spatial Resolution

The spatial resolution of each pixel is dependent on the off-nadir scan angle of 
the sensor and increases from nadir to the scanning extremes.  The satellite 
subpoint resolution of the various channels is:

                North/South         East/West
                -----------         ---------
Visible            1 km                1 km
IR2                4 km                4 km
IR3                8 km                4 km
IR4                4 km                4 km
IR5                4 km                4 km

The spatial dimensions of each pixel can be calculated from the provided 
latitude and longitude coordinate information (see Section 8.2).

7.1.4 Projection

The BOREAS level-1a GOES-8 images are stored in the same GOES perfect 
projection as the level-1 images.  The perfect projection indicates that the 
satellite movement between temporal acquisitions has been removed so the images 
are aligned spatially. Detailed information about the projection is not 
currently available.

7.1.5 Grid Description

Not available at this revision.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

From 14-Jul-1995 through 21-Sep-1995, partial to complete data are available for 
68 of the possible 70 days.

From 12-Feb-1996 to 03-Oct-1996, partial to complete data are available for 201 
of the possible 235 days.  One large period of missing data is 19-Jun-1996 to 
03-Jul-1996, which resulted from hardware problems at FSU.

7.2.2 Temporal Coverage Map

Not available.

7.2.3 Temporal Resolution

From 14-Jul-1995 to 21-Sep-1995, visible, IR4, and IR3 images were acquired at 
15 and 45 minutes after the hour, 24 hours a day.

During 1996, the visible, IR2, IR3, IR4, and IR5 images were acquired at 15 and 
45 minutes after the hour, 24 hours a day.

7.3 Data Characteristics

The image inventory data file characteristics are defined in the companion data 
definition file (goes81a.def).

7.3.1 Parameter/Variable

The parameter contained in the image data files is:
Digital Number (DN)

7.3.2 Variable Description/Definition

The quantized digital number derived by the GOES-8 scanning system for the 
respective channel.

7.3.3 Unit of Measurement

For the image data files:
Digital Number (DN) - counts

7.3.4 Data Source

The level-1a GOES-8 image bands were processed from the level-1 data.  The raw 
data were received, processed and subset, and sent to BORIS by personnel within 
the Department of Meteorology at Florida State University (FSU).

7.3.5 Data Range

In 1995, the maximum range of digital numbers in each GOES-8 image band is 
limited from 0 (zero) to 255 so that the values can be stored in a single 8-bit 
(byte) field.  For the 1996 data, each digital number can range from 0 to 1023 
and occupies 10-bits of the 16-bit field used to store the value.

7.4 Sample Data Record

A sample data record for the level-1a GOES-8 images is not available here.


8. Data Organization

8.1 Data Granularity

The smallest unit of data for level-1a GOES-8 image data is a single level-1a 
image.  This includes extracted descriptive information in ASCII form, all 
visible and infrared images collected within a given day of 0015 to 2345 
Greenwich Mean Time (GMT), and the reference latitude and longitude files for 
the images.

All of the BOREAS RSS-14 Level-1a GOES-8 Visible, IR, and Water-Vapor Images 
data are contained in one dataset.

8.2 Data Format(s)

The image inventory data file contains numerical and character fields of varying 
length separated by commas. The character fields are enclosed with a single 
apostrophe marks. There are no spaces between the fields. The image inventory 
data file format is defined in the companion data definition file (goes81a.def).

One day of level-1a GOES-8 data from 1995 is contained in four physical tape 
files:

1) ASCII header file
2) Visible image data file
3) IR4 image data file
4) IR3 image data file

One day of level-1a GOES-8 data from 1996 is contained in six physical tape 
files:

1) ASCII header file
2) Visible image data file
3) IR2 image data file
4) IR4 image data file
5) IR5 image data file
6) IR3 image data file

The ASCII header file contains 80-byte ASCII records that describe the level-1a 
product, provide summary and detailed information about the good and zero-
filled images for the given day, and contain descriptive header information 
extracted from the visible, IR2, IR4, IR5, and IR3 images.

Note that the data set consisted of three bands in 1995 and changed to five 
bands in 1996.  In addition, the size of the images also changed during 1995 and 
1996.  The following table describes the changes, and the following paragraphs 
give details of the binary data formats.


                                           Number     Number      Number
Start Date       End Date       Band      of Bits    of Lines    of Pixels
-----------     ----------    --------    -------    --------    ---------
14-Jul-1995      29-July-1995  visible       8         1024        1024
                                 IR4         8          256         256
                                 IR3         8          256         256
02-Aug-1995      21-Sep-1995   visible       8          824        2048
                                 IR4         8          256         512
                                 IR3         8          256         512
12-Feb-1996      30-Apr-1996   visible      16          824        2048
                                 IR2        16          256         512
                                 IR4        16          256         512
                                 IR5        16          256         512
                                 IR3        16          256         512
02-May-1996      03-Oct-1996   visible      16          824        2248
                                 IR2        16          256         612
                                 IR4        16          256         612
                                 IR5        16          256         612
                                 IR3        16          256         612

8.2.1 GOES-8 Three-Band Data Format (14-Jul-1995 to 29-Jul-1995)

One GOES-8 visible image contains 1,024 unsigned 8-bit counts (i.e., values from 
0 to 255) stored in unsigned 8-bit (1-byte) values in each of 1,024 lines.  A 
full day of visible image data consists of 48 half-hourly images acquired every 
30 minutes starting at 0015 GMT.  The visible image data file on tape contains a 
full day of image data.  Each visible image data file on tape consists of 3,072 
records of 16,384 bytes.  Each tape record contains 16 visible image lines of 
1024 bytes (16,384 = 16 * 1024).  Therefore, one visible image is contained in 
64 tape records (64 = 1024 / 16).  The sequence of image times in the file is 
0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly visible 
image was not acquired, the level-1a product contains a set of 1,024 records 
containing 1,024 values of 0.  The presence of these zero-filled images is shown 
in the ASCII header file.  Placing these zero-filled images in the file for 
missing acquisitions keeps the images from the same time in the same physical 
location in each daily file.

One GOES-8 IR4 image contains 256 unsigned 8-bit counts (i.e., values from 0 to 
255) stored in unsigned 8-bit (1-byte) values in each of 256 lines.  A full day 
of IR4 image data consists of 48 half-hourly images.  The IR4 image data file on 
tape contains a full day of image data.  Each IR4 image data file on tape 
consists of 192 records of 16,384 bytes.  Each tape record contains 64 IR image 
lines of 256 bytes (16,384 = 64 * 256).  Therefore, one IR4 image is contained 
in four tape records.  The sequence of image times in the file is 0015, 0045, 
0115, 0145, 2315, 2345 GMT.  If a given half-hourly IR4 image was not acquired, 
the level-1a product contains a set of 256 records containing 256 values of 0.  
The presence of these zero-filled images is shown in the ASCII header file.  
Placing these zero-filled images in the file for missing acquisitions keeps the 
images from the same time in the same physical location in each daily file.

One GOES-8 IR3 image contains 256 unsigned 8-bit counts (i.e., values from 0 to 
255) stored in unsigned 8-bit (1-byte) values in each of 256 lines.  A full day 
of IR3 image data consists of 48 half-hourly images.  The IR3 image data file on 
tape contains a full day of image data.  Each IR3 image data file on tape 
consists of 192 records of 16,384 bytes.  Each tape record contains 64 water-
vapor image lines of 256 bytes (16,384 = 64 * 256).  Therefore, one IR3 image is 
contained in four tape records.  The sequence of image times in the file is 
0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly IR3 image 
was not acquired, the level-1a product contains a set of 256 records containing 
256 values of 0.  The presence of these zero-filled images is shown in the ASCII 
header file.  Placing these zero-filled images in the file for missing 
acquisitions keeps the images from the same time in the same physical location 
in each daily file.

The set of six reference latitude and longitude files for the GOES-8 images 
collected in 1995 is appended as the last six files of the delivered tape. The 
six files consist of a pair of latitude and longitude files for each of the 
visible, IR2, and IR3 image types.

The reference latitude and longitude files for the visible images each consist 
of 1,024 records of 4,096 bytes.  Each record of 4,096 bytes contains 1,024 
signed 32-bit (4-byte) integer latitude or longitude values.  The bytes of each 
32-bit value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR4 images each consist of 
256 records of 1,024 bytes.  Each record of 1,024 bytes contains 256 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR3 images each consist of 
256 records of 1,024 bytes.  Each record of 1,024 bytes contains 256 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

8.2.2 GOES-8 Three-Band Data Format (01-Aug-1995 to 21-Sep-1995)

One GOES-8 visible image contains 2,048 unsigned 8-bit counts (i.e., values from 
0 to 255) stored in unsigned 8-bit (1-byte) values in each of 824 lines.  A full 
day of visible image data consists of 48 half-hourly images acquired every 30 
minutes starting at 0015 GMT.  The visible image data file on tape contains a 
full day of image data.  Each visible image data file on tape consists of 4,944 
records of 16,384 bytes.  Each tape record contains eight visible image lines of 
2,048 bytes (16,384 = 8 * 2048).  Therefore, one visible image is contained in 
103 tape records (103 = 824 / 8).  The sequence of image times in the file is 
0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly visible 
image was not acquired, the level-1a product contains a set of 824 records 
containing 2,048 values of 0.  The presence of these zero-filled images is shown 
in the ASCII header file.  Placing these zero-filled images in the file for 
missing acquisitions keeps the images from the same time in the same physical 
location in each daily file.

One GOES-8 IR4 image contains 512 unsigned 8-bit counts (i.e., values from 0 to 
255) stored in unsigned 8-bit (1-byte) values in each of 256 lines.  A full day 
of IR4 image data consists of 48 half-hourly images.  The IR4 image data file on 
tape contains a full day of image data.  Each IR4 image data file on tape 
consists of 384 records of 16,384 bytes.  Each tape record contains 32 IR4 image 
lines of 256 bytes (16,384 = 32 * 512).  Therefore, one IR4 image is contained 
in eight tape records (8 = 256 / 32).  The sequence of image times in the file 
is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly IR4 image 
was not acquired, the level-1a product contains a set of 256 records containing 
512 values of 0.  The presence of these zero-filled images is shown in the ASCII 
header file.  Placing these zero-filled images in the file for missing 
acquisitions keeps the images from the same time in the same physical location 
in each daily file.

One GOES-8 IR3 image contains 512 unsigned 8-bit counts (i.e., values from 0 to 
255) stored in unsigned 8-bit (1-byte) values in each of 256 lines.  A full day 
of IR3 image data consists of 48 half-hourly images.  The IR3 image data file on 
tape contains a full day of image data.  Each IR3 image data file on tape 
consists of 384 records of 16,384 bytes.  Each tape record contains 32 IR3 image 
lines of 512 bytes (16,384 = 32 * 512).  Therefore, one IR3 image is contained 
in eight tape records(8 = 256 / 32).  The sequence of image times in the file is 
0015, 0045, 0115, 0145, 2315, 2345 GMT.  If a given half-hourly IR3 image was 
not acquired, the level-1a product contains a set of 256 records containing 512 
values of 0.  The presence of these zero-filled images is shown in the ASCII 
header file.  Placing these zero-filled images in the file for missing 
acquisitions keeps the images from the same time in the same physical location 
in each daily file.

The set of six reference latitude and longitude files for the GOES-8 images 
collected in 1995 is appended as the last six files of the delivered tape. The 
six files consist of a pair of latitude and longitude files for each of the 
visible, IR4, and IR3 image types.

The reference latitude and longitude files for the visible images each consist 
of 824 records of 8,192 bytes.  Each record of 8,192 bytes contains 2,048 signed 
32-bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR4 images each consist of 
256 records of 2,048 bytes.  Each record of 2,048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR3 images each consist of 
256 records of 2,048 bytes.  Each record of 2,048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.


8.2.3 GOES-8 Five-Band Data Format (12-Feb-1996 to 30-Apr-1996)

One GOES-8 visible image contains 2,048 10-bit counts (i.e., values from 0 to 
1023) stored in 16-bit (2-byte) values (low-order byte first) in each of 824 
lines.  A full day of visible image data consists of 48 half-hourly images 
acquired every 30 minutes starting at 0015 GMT.  The visible image data file on 
tape contains a full day of image data.  Each visible image data file on tape 
consists of 9,888 records of 16,384 bytes.  Each tape record contains four 
visible image lines of 4,096 bytes (16,384 = 4 * 4096).  Therefore, one visible 
image is contained in 206 tape records (206 = 824 / 4).  The sequence of image 
times in the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given 
half-hourly visible image was not acquired, the level-1a product contains a set 
of 824 records containing 2,048 16-bit values of 0.  The presence of these zero-
filled images is shown in the ASCII header file.  Placing these zero-filled 
images in the file for missing acquisitions keeps the images from the same time 
in the same physical location in each daily file.

One GOES-8 IR2 image contains 512 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low order byte first) in each of 256 lines.  A 
full day of IR2 image data consists of 48 half-hourly images.  The IR2 image 
data file on tape contains a full day of image data.  Each IR2 image data file 
on tape consists of 768 records of 16,384 bytes.  Each tape record contains 16 
IR2 image lines of 1,024 bytes (16,384 = 16 * 1024).  Therefore, one IR2 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR2 image was not acquired, the level-1a product contains a set of 256 records 
containing 512 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR4 image contains 512 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR4 image data consists of 48 half-hourly images.  The IR4 image 
data file on tape contains a full day of image data.  Each IR4 image data file 
on tape consists of 768 records of 16,384 bytes.  Each tape record contains 16 
IR4 image lines of 1,024 bytes (16,384 = 16 * 1024).  Therefore, one IR4 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR4 image was not acquired, the level-1a product contains a set of 256 records 
containing 512 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR5 image contains 512 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR5 image data consists of 48 half-hourly images.  The IR5 image 
data file on tape contains a full day of image data.  Each IR5 image data file 
on tape consists of 768 records of 16,384 bytes.  Each tape record contains 16 
IR5 image lines of 1,024 bytes (16,384 = 16 * 1024).  Therefore, one IR5 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR5 image was not acquired, the level-1a product contains a set of 256 records 
containing 512 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR3 image contains 512 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR3 image data consists of 48 half-hourly images.  The IR3 image 
data file on tape contains a full day of image data.  Each IR3 image data file 
on tape consists of 768 records of 16,384 bytes.  Each tape record contains 16 
IR3 image lines of 1,024 bytes (16,384 = 16 * 1024).  Therefore, one IR3 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR3 image was not acquired, the level-1a product contains a set of 256 records 
containing 512 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

The set of 10 reference latitude and longitude files for the GOES-8 images 
collected in 1995 is appended as the last 10 files of the delivered tape. The 10 
files consist of a pair of latitude and longitude files for each of the visible, 
IR2, IR3, IR4, and IR5 image types.

The reference latitude and longitude files for the visible images each consist 
of 824 records of 8,192 bytes.  Each record of 8,192 bytes contains 2,048 signed 
32-bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR2 images each consist of 
256 records of 2,048 bytes.  Each record of 2048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR4 images each consist of 
256 records of 2,048 bytes.  Each record of 2,048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR5 images each consist of 
256 records of 2,048 bytes.  Each record of 2,048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR3 images each consist of 
256 records of 2,048 bytes.  Each record of 2,048 bytes contains 512 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.


8.2.4 GOES-8 Five-Band Data Format (02-May-1996 to 03-Oct-1996)

One GOES-8 visible image contains 2,248 10-bit counts (i.e., values from 0 to 
1023) stored in 16-bit (2-byte) values (low-order byte first) in each of 824 
lines.  A full day of visible image data consists of 48 half-hourly images 
acquired every 30 minutes starting at 0015 GMT.  The visible image data file on 
tape contains a full day of image data.  Each visible image data file on tape 
consists of 9,888 records of 17,984 bytes.  Each tape record contains four 
visible image lines of 4,496 bytes (17,984 = 4 * 4496).  Therefore, one visible 
image is contained in 206 tape records (206 = 824 / 4).  The sequence of image 
times in the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given 
half-hourly visible image was not acquired, the level-1a product contains a set 
of 824 records containing 2,248 16-bit values of 0.  The presence of these zero-
filled images is shown in the ASCII header file.  Placing these zero-filled 
images in the file for missing acquisitions keeps the images from the same time 
in the same physical location in each daily file.

One GOES-8 IR2 image contains 612 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR2 image data consists of 48 half-hourly images.  The IR2 image 
data file on tape contains a full day of image data.  Each IR2 image data file 
on tape consists of 768 records of 19,584 bytes.  Each tape record contains 16 
IR2 image lines of 1,224 bytes (19,584 = 16 * 1224).  Therefore, one IR2 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR2 image was not acquired, the level-1a product contains a set of 256 records 
containing 612 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR4 image contains 612 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR4 image data consists of 48 half-hourly images.  The IR4 image 
data file on tape contains a full day of image data.  Each IR4 image data file 
on tape consists of 768 records of 19,584 bytes.  Each tape record contains 16 
IR4 image lines of 1,224 bytes (19,584 = 16 * 1224).  Therefore, one IR4 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR4 image was not acquired, the level-1a product contains a set of 256 records 
containing 612 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR5 image contains 612 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR5 image data consists of 48 half-hourly images.  The IR5 image 
data file on tape contains a full day of image data.  Each IR5 image data file 
on tape consists of 768 records of 19,584 bytes.  Each tape record contains 16 
IR5 image lines of 1,224 bytes (19,584 = 16 * 1224).  Therefore, one IR5 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR5 image was not acquired, the level-1a product contains a set of 256 records 
containing 612 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

One GOES-8 IR3 image contains 612 10-bit counts (i.e., values from 0 to 1023) 
stored in 16-bit (2-byte) values (low-order byte first) in each of 256 lines.  A 
full day of IR3 image data consists of 48 half-hourly images.  The IR3 image 
data file on tape contains a full day of image data.  Each IR3 image data file 
on tape consists of 768 records of 19,584 bytes.  Each tape record contains 16 
IR3 image lines of 1,224 bytes (19,584 = 16 * 1224).  Therefore, one IR3 image 
is contained in 16 tape records (16 = 256 / 16).  The sequence of image times in 
the file is 0015, 0045, 0115, 0145, ... 2315, 2345 GMT.  If a given half-hourly 
IR3 image was not acquired, the level-1a product contains a set of 256 records 
containing 612 16-bit values of 0.  The presence of these zero-filled images is 
shown in the ASCII header file.  Placing these zero-filled images in the file 
for missing acquisitions keeps the images from the same time in the same 
physical location in each daily file.

The set of 10 reference latitude and longitude files for the GOES-8 images 
collected in 1995 are appended as the last 6 files of the delivered tape. The 10 
files consist of a pair of latitude and longitude files for each of the visible, 
IR2, IR3, IR4, and IR5 image types.

The reference latitude and longitude files for the visible images each consist 
of 824 records of 8,992 bytes.  Each record of 8,992 bytes contains 2,248 signed 
32-bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR2 images each consist of 
256 records of 2,448 bytes.  Each record of 2,448 bytes contains 612 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR4 images each consist of 
256 records of 2,448 bytes.  Each record of 2,448 bytes contains 612 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR5 images each consist of 
256 records of 2,448 bytes.  Each record of 2,448 bytes contains 612 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.

The reference latitude and longitude files for the IR3 images each consist of 
256 records of 2,448 bytes.  Each record of 2,448 bytes contains 612 signed 32-
bit (4-byte) integer latitude or longitude values.  The bytes of each 32-bit 
value are stored as low-order byte first.  The unit of each latitude and 
longitude value is thousandths of a degree.  To get the original decimal degree 
values, divide each value by 1000.


9. Data Manipulations

9.1 Formulae

9.1.1 Derivation Techniques and Algorithms

See Section 9.2.1.

9.2 Data Processing Sequence

9.2.1 Processing Steps

Using the BOREAS level-1 GOES-8 product as input, the data were processed to 
level-1a products. The processing included:

1) Separating the header record and image data records contained in level-1 GOES 
image files.
2) Unpacking the header record information for use in processing control and 
output to the level-1a ASCII header file.
3) Filling missing images with zero-filled records.
4) Writing the four files for each day's data to disk.
5) Copying a 4-week period of daily files to tape.
6) Appending the reference latitude and longitude files to the tapes.

9.2.2 Processing Changes

None.

9.3 Calculations

See Section 9.1.1.

9.3.1 Special Corrections/Adjustments

See Section 9.1.1.

9.3.2 Calculated Variables

See Section 9.1.1.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

The level-1a processing depended on the times provided in the level-1 GOES-8 
image header records.  If the time in the level-1 GOES-8 header record is 
incorrect, it would result in the image being placed in the incorrect sequence 
in the level-1a product.  Any mixup between visible, IR2, IR3, IR4, and IR5, 
images could not occur because of the file type and size checking done during 
processing.

10.2 Quality Assessment

10.2.1 Data Validation by Source

Whatever the processing level, the geometric quality of the image depends on the 
accuracy of the viewing geometry. 

Spectral errors could arise from image-wide signal-to-noise ratio, saturation, 
cross-talk, spikes, or response normalization caused by a change in gain.

10.2.2 Confidence Level/Accuracy Judgment

Not available at this revision.

10.2.3 Measurement Error for Parameters

Not available at this revision.

10.2.4 Additional Quality Assessments

The level-1 GOES-8 images used to create the level-1a products were visually 
scanned for bad periods by FSU staff.


10.2.5 Data Verification by Data Center

See Section 9.1.1.

11. Notes

11.1 Limitations of the Data

Not available at this revision.

11.2 Known Problems with the Data

To date, the following discrepancies/problems have been noted in the data: 

1) Occasional reception problems, especially during NOAA rapid scan operations, 
may result in some images being truncated at the northern edge (top of image).  
When this occurs, visual review by FSU staff has ensured that the BOREAS areas 
of interest are still present.
2) The ASCII header files for the level-1a GOES-8 images up to day 97 of 1996 
(06-Apr-19960) contain the incorrect relative file numbers for the IR2, IR4, 
IR5, and IR3 files.  An incorrect header file shows the IR2, IR4, IR5, and IR3 
data to be contained in files 03, 03, 03, and 04.  The actual file numbers are 
3, 4, 5, and 6.  This was fixed for data after day 97.

11.3 Usage Guidance

None.

11.4 Other Relevant Information

None.

12. Application of the Data Set

The GOES-8 images provide a high temporal resolution data set that would be 
useful for monitoring radiation loading and cloud development and movement over 
the BOREAS region.

13. Future Modifications and Plans

None.

14. Software

14.1 Software Description

BORIS staff developed software and command procedures for:

1) Extracting header information from level GOES-8 images on tape and writing it 
to ASCII files on disk for initial quality checking. 

2) Processing the files of level-1 GOES-8 data for a given day to a level-1a 
product.

3) Writing the level-1a GOES-8 image files from tape to disk.

4) Creating binary files of scaled latitude and longitude coordinates from the 
original ASCII files.

5) Appending the latitude and longitude files to tape.

The software mentioned above is written in the C language and is operational on 
VAX 6410, MicroVAX, and VAXstation systems at GSFC.  The primary dependencies in 
the software are the tape input/output (I/O) library and the Oracle data base 
utility routines.

14.2 Software Access

All of the described software is available upon request (See Section 15).  BORIS 
staff would appreciate knowing of any problems discovered with the software, but 
cannot guarantee that they will be fixed.

15. Data Access

15.1 Contact Information

Ms. Beth Nelson
BOREAS Data Manager
NASA GSFC
Greenbelt, MD 
(301) 286-4005
(301) 286-0239 (fax)
beth@ltpmail.gsfc.nasa.gov

15.2 Data Center Identification

See 15.1.

15.3 Procedures for Obtaining Data

Users may place requests by telephone, electronic mail, or fax.

15.4 Data Center Status/Plans

The level-1a GOES-8 data are available from the Earth Observing System Data and 
Information System (EOSDIS), Oak Ridge National Laboratory (ORNL), Distributed 
Active Archive Center (DAAC). The BOREAS contact at ORNL is: 

ORNL DAAC User Services
Oak Ridge National Laboratory
Oak Ridge, TN 
(423) 241-3952
ornldaac@ornl.gov
ornl@eos.nasa.gov

16. Output Products and Availability

16.1 Tape Products

The level-1a GOES-8 data can be made available on 8-mm tapes or Digital Archive 
Tapes (DAT). 

16.2 Film Products

None.

16.3 Other Products

None.

17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

Bobotek, A., A.S. Hechtman, R.J. Komajoa, and P.G. Woolner. July 1995. GOES I-M 
System description. MITRE Corporation.

Rossow, W.B., C.L. Brest, and M. Roiter. 1996. International Satellite Cloud 
Climatology Project (ISCCP) New Radiance Calibrations. WMO/TD-No. 736. World 
Meteorological Organization.

Rossow, W.B., C.L. Brest, and M.D. Roiter. 1995.  International Satellite Cloud 
Climatology Project (ISCCP):  Update of radiance calibration report.  Technical 
Document, World Climate Research Programme (ICSU and WMO), Geneva, Switzerland, 
76 pp.

Rossow, W.B., Y. Desormeaux, C. L. Brest, and A. Walker.  1992. International 
Satellite Cloud Climatology Project (ISCCP):  Radiance calibration report.  
WMO/Technical Document No. 520, World Climate Research Programme and World 
Meteorological Organization (ICSU and WMO), Geneva, Switzerland, 104 pp.

17.2 Journal Articles and Study Reports

Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). 

Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). 

Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere 
Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). 

Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere 
Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). 

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. 
Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. 
Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and 
early results from the 1994 field year. Bulletin of the American Meteorological 
Society. 76(9):1549-1577. 

17.3 Archive/DBMS Usage Documentation

None.

18. Glossary of Terms

None.

19. List of Acronyms

    AOCS    - Attitude and Orbit Control System
    ASCII   - American Standard Code for Information Interchange
    ATS     - Application Technology Satellite
    BB      - Blackbody
    BOREAS  - BOReal Ecosystem-Atmosphere Study
    BORIS   - BOREAS Information System
    BPI     - Bytes Per Inch
    CCT     - Computer Compatible Tape
    CDA     - Command and Data Acquisition
    CD-ROM  - Compact Disk-Read-Only Memory
    DAAC    - Distributed Active Archive Center
    DAT     - Digital Archive Tape
    DC      - Dark Current
    DN      - Digital Number
    ECAL    - Electronic Calibration
    EOS     - Earth Observing System
    EOSDIS  - EOS Data and Information System
    ESD     - Environmental Satellite Data, Inc.
    E-W     - East-West
    FFC     - Focused Field Campaign
    FSU     - Florida State University
    GIMTACS - GOES I-M Telemtry and Command System
    GMT     - Greenwich Mean Tim
    GOES    - Geostationary Operational Environmental Satellite
    GSFC    - Goddard Space Flight Center
    GVAR    - GOES VARiable
    IFC     - Intensive Field Campaign
    IFOV    - Instantaneous Field of View
    IGFOV   - Instantaneous Geometric Field of View
    IMC     - Image Motion Compensation
    INR     - Instrument Navigation & Registration
    I/O     - Input/Output
    IR      - Infrared
    ISLSCP  - International Satellite Land Surface Climatology Project
    MMC     - Mirror Motion Compensation
    NAD83   - North American Datum of 1983
    NASA    - National Aeronautics and Space Administration
    NESDIS  - National Environmental Satellite, Data and Information Service
    NLUT    - Normalization Look-Up Table
    NOAA    - National Oceanic and Atmospheric Administration
    N-S     - North-South
    NSA     - Northern Study Area
    NWS     - National Weather Service
    OATS    - Orbit and Altitude Tracking System
    OGE     - Operations Ground Equipment
    ORNL    - Oak Ridge National Laboratory
    PANP    - Prince Albert National Park
    PM      - Product Monitor
    PMS     - Performance Monitoring System
    RSS     - Remote Sensing Science
    SDI     - Sensor Data Interface
    SEM     - Space Environmental Monitoring
    SMS     - Synchronous Meteorological Satellites
    SPS     - Sensor Processing Subsystem
    SSA     - Southern Study Area
    SS/L    - Space Systems/Loral, Inc.
    T&C     - Telemetry and Command
    URL     - Uniform Resource Locator
    VAS     - VISSR Atmospheric Sounder
    VISSR   - Visible and Infrared Spin Scan Radiometer
    
20. Document Information

20.1 Document Revision Dates

Written:         25-Jul-1995
Last Updated:    07-May-1998

20.2 Document Review Dates

BORIS Review:    24-Apr-1998
Science Review: 

20.3 Document ID

20.4 Citation

The level-1a GOES-8 images resulted from a joint effort between BOREAS staff at 
NASA GSFC and Dr. Eric Smith of FSU. The original data were acquired by FSU and 
processed to level-1 products. The present level-1a product was created by 
BORIS.   The respective contributions of the above individuals and agencies to 
completing this data set are greatly appreciated.

20.5 Document Curator

20.6 Document URL

Keywords

GOES-8
EMITTED RADIATION
REFLECTED RADIATION
WATER VAPOR
RSS14_GOES8_L1A.doc
05/26/98