NASA/TMm2000-209891, Vol. 66

Technical Report Series on the

Boreal Ecosystem-Atmosphere Study (BOREAS)

Forrest G. Hall, Editor

Volume 66

BOREAS RSS-14 Levei-la GOES-8

Visible, IR and Water Vapor Images

Jeffrey A. Newcomer, Raytheon ITSS

David Faysash, Harry J. Coopel, and Eric A. Smith, Florida State Universi_

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

August 2000

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NASA Center for AeroSpace Information

7 i 21 Standard Drive

Hanover, MD 21076-1320

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Available from:

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BOREAS RSS-14 Level-la GOES-8 Visible, Infrared, and Water-Vapor

Images

Jeffrey A. Newcomer, David Faysash, Harry J. Cooper, Eric A. Smith

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-la 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.

Note: due to the large size of the images, the level-I a GOES-8 data are not contained on the

BOREAS CD-ROM set. An inventory listing file is supplied on the CD-ROM to inform users of what

data were collected. The level-1 a GOES-8 image data are available from the Earth Observing System

Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active

Archive Center (DAAC). See sections 15 and 16 for more information.

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

Page 1
1. Data Set Overview

1.1 Data Set Identification

BOREAS RSS-14 Level-la GOES-8 Visible, Infrared, and Water-Vapor Images

1.2 Data Set Introduction

For the BOReal Ecosystem-Atmosphere Study (BOREAS), the level-1 a 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-1 a 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-1 a GOES-8 data set

starts out as a three-band, 8-bit data set in 1995 and changes to a five-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 of Florida State University (FSU) provided BORIS with the level- 1 GOES-8

images that were used to create the level-1 a products. BORIS staff processed the level-la GOES-8

images by: l) summarizing and extracting header information from the level-1 GOES-8 images 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 online data base with needed information.

1.6 Related Data Sets

BOREAS RSS-14 Level-1 GOES-7 Images from 1994 and 1995

BOREAS RSS-14 Level-la GOES-7 Images from 1994 and 1995

BOREAS RSS-14 Level-2 GOES-7 1994 Surface Radiation Data

BOREAS RSS- 14 Level- 1 GOES-8 Images from 1995 and 1996

2. Investigator(s)

2.1 Investigator(s) Name and Title

Dr. Eric A. Smith, Professor

Department of Meteorology

Florida State University

Tallahassee, FL 32306-3034

2.2 Title of Investigation

GOES Imagery for the BOREAS Experimental Areas

Page 2
2.3 Contact Information

Contact 1:

Jeffrey A. Newcomer

Raytheon ITSS

Code 923

NASA GSFC

Greenbelt, MD 20771

(301) 286-7858

(301) 286-0239 (fax)

Jeffrey.Newcomer@ gsfc.nasa.gov

Contact 2:

Dr. Eric A. Smith

306 Love Building

Dept. of Meteorology

Florida State University

Tallahassee, FL 32306-3034

(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.

Page 3
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

Visible/Silicon

Shortwave/InSb

Moisture/HgCdTe

Longwave I/HgCdTe

Longwave 2/HgCdTe

Instantaneous Field of View (IFOV)

: 1 km

: 4 km

: 8 km

• 4 km

: 4 km

Radiometric Calibration: Space and 290 Kelvin IR internal blackbody

Signal Quantizing (NE'delta'T)

S/N

: i0 bits all channels

: Minimum 3X better than specifications

Frequency of Calibration Space

Infrared

: 2.2 sec for full disk;

9.2 or 36.6 sec for sector/area

30 minutes typical

System Absolute Accuracy iR channel less than 0.I K

Transmit Frequency : 1676.00 MHz

Page 4
4.1.1 Collection Environment

The GOES-8 data were acquired using the FSU Direct Readout Ground System located in

Tal|ahassee, 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

GOES-8

Launch Date Data Range

13-Apt-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 mission's 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.

Page 5
ThesefunctionshaveresulteddirectlyfromtheoverallsystemrequirementsdevelopedbyNOAAand

NASAtogetherwiththeNationalWeatherService(NWS),thesystem'sprimaryuser.Manyof the

requirementsarecontinuedmissionsfrom thepreviousGOESD-Hseriesof spacecraft.However,

technological advancementshaveprovidedsignificantimprovementsin thereliabilityandavailabilityof

thesesystemsforthenewGOESI-M series.

As inthepreviousGOESmission,theGOESI-M systemprovidestheaboveservicesovera

regioncoveringthecentralandeastemPacificOcean,the48contiguousStates,andthecentraland

westernAtlantic 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 GOES I-M generation of spacecraft has been developed by 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 spacecraft's Imaging and

Sounding instruments can be operated simultaneously and independently of one another.

The spacecraft's configuration is 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 five-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

The flexible nature of the Imager is used to provide a star-sensing capability. Time and location of

a star are 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 time that are 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 are in

the normal format and data stream for extraction and use at the ground station. 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 multichannel instrument designed to sense radiant and solar-reflected energy from

sampled areas of Earth's surface and atmosphere. The Imager's 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.

Page 6
Radiometricqualityof 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 unit's 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 instrument's 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 radiometfic 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

(v l-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 jam) contains two square detectors, one primary and one redundant. Each

provides an IGFOV of 224 microradians corresponding to an

Page 7
8-kmresolutionatthesubsatellitepoint.

• IR Channels 2 (3.9 _m), 4 (10.7 _m), and 5 (12.0 lam) 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 instrument's 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 FIT

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)

Page 8
hardware,throughuseof look-uptables.ForImagerandSounderIR data,calibrationisperformedby

theSPSsoftware,usingthecalculatedcalibrationcoefficients.

ImagerdataareingestedintotheSPSviatheSDIasaserialbit stream.Followingingest

processmg,includingbit andframesynchronization,theSDIhardwareunderSPSsoftwarecontrol

performsnormalizationof thevisibledata.TheSDI hardwareusestheradiometriclook-uptablesto

normalizeImagervisibledatabycompensatingfor variationinthesatellitedetectoresponsecurves

overtime.TheappropriatetablesareloadedfromtheSPSmemoryintoSDIhardwaretables,underthe

controlof theImagerInterfacetask.Theselook-uptablesareusedbytheSDIto locatethecorrect

valuefor adetectorpixel.Therearedifferenttablesfor eachof theeightImagervisibledetectors.

Theseradiometrictablesareloadedwithvaluesthathavebeenadjustedtoincorporatethelatest

normalizationinformation.ImagerIR dataaredepositedin SPSmemorywithoutanylinear

transformations. Calibrationisthenperformedby SPSsoftwareusingtheactualcalibrationequations

fortheIR detectors.Sounderdataaredepositedin theSPSmemorybytheSDI,followingingest

.processing. TheSounderDataFormattertaskcalibratesSounderIR dataandnormalizesvisibledata,

mSPSsoftware,usingtheactualcalibrationequationsfortheIR andlook-uptablesfor thevisible.

Theperiodiccalibrationcoefficientgeneratingprocessisperformedto ensurethatthebestpossible

coefficientvaluesareusedwhencalibratingImagerandSounderIR data.Thisprocessallowsfor

periodicrecalculationof thecoefficientscontainedin thecalibrationdatabaseof theSPS.Spacecraft

instrumentdataareprovidedtotheSPSinsupportof thisoperation.Thissectiondefinesthedata

receivedfromtheImagerandSounderandtheirusein thedetectorcalibrationprocess.

TheImagerandSounderinthespacecraftperformperiodicin-flightsequencesthatsupportIR

calibrationprocessingtheOGE.Theinstrumentinformationgeneratedincludesspacelook,BB

calibration,andElectronicCalibration(ECAL).

A spacelooksequenceprovidesradiometricdatafor all detectorsfromaviewof spacelocated

beyondtheedgeofEarth.TheImagercanperformspacelooksintwo ways.Theinstrumentscancan

beinterruptedandthemirrorpointedto spacetotakeareading;thisis calledaspaceclamp.Theframe

canalsobemadesuchthateithertheleft sideortheright sideextendsbeyondEarth'sedge,beyond

Earthshine,intospace,makingtheinstrumentscanspace;thisis calledascanclamp.

In spaceclampmode,theImagerperformsaspaceclampatthestartof aframewithsubsequent

spaceclampsperformedupontheexecutionof atimer.Thetimerisselectedat9.2secondsor36.6

seconds;thetimerrestartsuponexpirationsothatspacelooksareatfixedintervals.Upontimer

expirations,theImagercompletesthelineit is scanning,slewshorizontallyto thepreselectedsideto a

point10.2° from nadirtoperformthespacelook,performsatumaroundsequence,andresumes

scanningtheframe.Theturnaroundsequenceincludesretracingthelastlinethreetimes,sothe

directionof theinterruptionisproportionaltothewidthof theframe.Thetotalamountof timethescan

isinterruptedisproportionalto thenumberof spacelooksperformed,andtherefore,to thetotalsizeof theframe.

In scanclampmode,theframescanisneverinterrupted,buttheframeactuallyscannedextends

outintospace,beyondtheareaof meteorological interest.TheframeedgeextendsbeyondEarth's

edge,beyondEarthshine,a0.5°-widering aroundEarth,andoutintospacefarenoughto acquirea

presetnumberof samples.Initially,thenumberof samplesobtainedbytheGOES-8Imagerwill be

400IR samples,64micronsoncenter,for adisplacementof 1.47° beyondEarthshine.Scanclamp

modewill typicallybeusedforfull diskframes,makingtheframeboundarylie 1.97° beyondEarth's

edgeattheEquator,10.67° fromnadir.In afull diskframescannedthus,withtheoverscanintospace

appliedonlyto onesideofEarth,i.e.,everyotherscanline,spacecalibrationdataareobtainedevery 2.2seconds.

TheSounderoperatesinaspaceclampmodesimilarto thatof theImager.TheSounderspace

clampmodeisitsonlymodeof operation.A spacelookisperformedbytheSounderevery2 minutes.

In normalandprioritymodes,aftereachlocationis sounded,atimerisexaminedto seeif aspacelook

isnecessary.TheSounderthensavesthecurrentaddressandslewsto thespacelocation.Upon

completion,theSounderchecksto determineif ECAL andBBcalibrationshouldbeperformed.If not,

theinstrumentreturnstotheoriginallocation.

A BBcalibrationconsistsof datasamplesfromaviewof theinstrument'sinternalBB. Bothspace

lookandECALdataaretransmittedaspartof theBBcalibrationoperation.TheECALdatagenerated

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areusedbythePM to monitorlinearityof theImagerandSounderinstrument'selectronicgain.In the

Imager,theBBcalibrationisnormallyperformedevery20minutes,unlessdoingsowouldmean

interruptinganimagein process.At themost,theImagermaygo30minutesbetweenBBviews.The

BBcalibrationprocessdoesnotinterruptanyotheroperationandcannotoccurduringaframe.The

onlyexceptiontothisisif aframeisinterruptedby apriority scanframeorastarsenseoperation. 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

coe_cients. 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 1 Is.

During Sounder operation, block 11 s 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

Page 10
GVAR,isreceivedbythePMequipment.Theoperatorselectsasectorcontainingcloudcover,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 detector's 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 detector's 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 System (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.

4.2.1.1 Tolerance

None given.

4.2.2 Frequency of Calibration

None given.

4.2.3 Other Calibration Information

None given.

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.

Page 11
6.1 Data Notes

None.

6.2 Field Notes

Not applicable.

6. Observations

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-la 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) comer coordinates of the BOREAS region are:

Latitude Longitude

Northwest 58.979°N iii.000 °W

Northeast 58.844°N 93.502°W

Southwest 51.000°N III.000°W

Southeast 50.089°N 96.969°W

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

The comer 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

Page 12
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 comer 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.

Northwest

Northeast

Southwest

Southeast

Visible Visible

Latitude Longitude

.....................

-999.000 -999.000

65.462 -98.345

47.809 -107.113

46.773 -87.996

Northwest

Northeast

Southwest

Southeast

IR4 IR4

Latitude Longitude

-999.000 -999.000

70.047 -104.477

46.147 -105.839

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 comer 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

Page 13
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 comer 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

Northwest

Northeast

Southwest

Southeast

IR2 IR2

Latitude Longitude

-999.000 -999.000

69.565 -99.365

46.293 -108.022

45.208 -86.229

Page 14
IR3

Latitude

IR3

Longitude

Northwest

Northeast

Southwest

Southeast

-999.000

-999.000

38.644

37.971

-999.000

-999.000

-103.275

-84.902

Northwest

Northeast

Southwest

Southeast

IR4

Latitude

-999.000

69.565

46.293

45.208

IR4

Longitude

-999.000

-99.365

-108.022

-86.229

IR5

Latitude

IR5

Longitude

Northwest -999.000

Northeast 69.565

Southwest 46.293

Southeast 45.208

-999.000

-99.365

-108.022

-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-1 a 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

Page 15
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-Ju1-1995 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

7.3.1 Parameter/Variable

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

The parameters contained in the inventory listing file on the CD-ROM are:

Column Name

SPATIAL COVERAGE

DATE OBS

START TIME

END TIME

PLATFORM

INSTRUMENT

NUM BANDS

BAND_QUALITY

CLOUD COVER

NUM VIS IMAGES

NUM IR2 IMAGES

NUM IR3 IMAGES

NUM IR4 IMAGES

NUM IR5 IMAGES

CRTFCN CODE

7.3.2 Variable Description/Definition

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

Column Name Description

SPATIAL_COVERAGE The general term used to denote the spatia2 area

over which the data were collected.

DATE OBS The date on which the data were collected.

START TIME The starting Greenwich Mean Time (GMT) for the

data collected.

END TIME The ending Greenwich Mean Time (GMT) for the

data collected.

PLATFORM The object (e.g., satellite, aircraft, tower,

person) that supported the instrument.

Page 16
INSTRUMENT

NUM BANDS

BAND_QUALITY

CLOUD COVER

NUM VIS IMAGES

NUM IR2 IMAGES

NUM IR3 IMAGES

NUM IR4 IMAGES

NUM IR5 IMAGES

CRTFCN CODE

The name of the device used to make the

measurements.

The number of spectral bands in the data.

The data analyst's assessment of the quality of

the spectral bands in the data.

The data analyst's assessment of the cloud cover

that exists in the data.

The number of visible GOES-8 images

that are contained in the image product.

The number of GOES-8 IR2 images that are

contained in the data unit.

The number of GOES-8 IR3 (water vapor) images

that are contained in the data unit.

The number of GOES-8 IR4 images that are

contained in the data unit.

The number of GOES-8 IR5 images that are

contained in the data unit.

The BOREAS certification level of the data.

Examples are CPI (Checked by PI), CGR (Certified

by Group), PRE (Preliminary), and CPI-??? (CPI

but questionable).

7.3.3 Unit of Measurement

Forthe imagedata files: Digital Number (DN) - count

The measurement units for the parameters contained in the inventory listing file on the CD-ROM are:

Column Name Units

SPATIAL COVERAGE [none]

DATE OBS [DD-MON-YY]

START TIME [HHMM GMT]

END TIME [HHMM GMT]

PLATFORM [none]

INSTRUMENT [none]

NUM BANDS [counts]

BAND QUALITY [none]

CLOUD COVER [none]

NUM VIS IMAGES [counts]

NUM IR2 IMAGES [counts]

NUM IR3 IMAGES [counts]

NUM IR4 IMAGES [counts]

NUM IR5 IMAGES [counts]

CRTFCN CODE [none]

Page 17
7.3.4 Data Source

Thelevel-la GOES-8imagebandswereprocessedfromthelevel-1data.Therawdatawere

received,processedandsubset,andsenttoBORISbypersonnelwithintheDepartmentof

MeteorologyatFloridaStateUniversity(FSU).Thesourcesof theparametervaluescontainedinthe

inventorylistingfile ontheCD-ROMare:

Column Name Data Source

SPATIAL COVERAGE [Constant software parameter value]

DATE OBS [Level-i GOES-8 header record]

START TIME [Constant software parameter value]

END TIME [Constant software parameter value]

PLATFORM [Constant software parameter value]

INSTRUMENT [Constant software parameter value]

NUM BANDS [Constant software parameter value]

BAND_QUALITY [Constant software parameter value]

CLOUD COVER [Constant software parameter value]

NUM VIS IMAGES [Count from processing software]

NUM IR2 IMAGES [Count from processing software]

NUM IR3 IMAGES [Count from processing software]

NUM IR4 IMAGES [Count from processing software]

NUM IR5 IMAGES [Count from processing software]

CRTFCN CODE [Constant data base value]

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.The following table gives inform_ion about the parame_r

_e CD-ROM.

Minimum Maximum

Data Data

Column Name Value Value

values found in the inventory table on

Missng Unrel Below Data

Data Data Detect Not

Value Value Limit Cllctd

SPATIAL COVERAGE N/A N/A None None None None

DATE OBS 14-JUL-95 03-OCT-96 None None None None

START TIME 15 15 None None None None

END TIME 2345 2345 None None None None

PLATFORM GOES-8 GOES-8 None None None None

INSTRUMENT N/A N/A None None None None

NUM BANDS 3 5 None None None None

BAND QUALITY N/A N/A None None None None

CLOUD COVER N/A N/A None None None None

NUM VIS IMAGES 1 48 None None None None

NUM IR2 IMAGES 2 48 None None None Blank

NUM IR3 IMAGES 1 48 None None None None

NUM IR4 IMAGES 1 48 None None None None

NUM IR5 IMAGES 1 48 None None None Blank

CRTFCN CODE CPI CPI None None None None

Minimum Data Value -- The minimum value found in the column.

Maximum Data Value -- The maximum value found in the column.

Missng Data Value -- The value that indicates missing data. This is used to

indicate that an attempt was made to determine the

Page 18
parameter value, but the attempt was unsuccessful.

Unrel Data Value -- The value that indicates unreliable data. This is used

to indicate an attempt was made to determine the

parameter value, but the value was deemed to be

unreliable by the analysis personnel.

Below Detect Limit -- The value that indicates parameter values below the

instruments detection limits. This is used to

indicate that an attempt was made to determine the

parameter value, but the analysis personnel determined

that the parameter value was below the detection

limit of the instrumentation.

Data Not Cllctd -- This value indicates that no attempt was made to

determine the parameter value. This usually

indicates that BORIS combined several similar but

not identical data sets into the same data base table

but this particular science team did not

measure that parameter.

Blank -- Indicates that blank spaces are used to denote that type of value.

N/A -- Indicates that the value is not applicable to the respective column.

None -- Indicates that no values of that sort were found in the column.

7.4 Sample Data Record

A sample data record for the level-1 a GOES-8 images is not available hem.The following are

wrapped versions of the first few records from the level-1 GOES-8 inventory table on the CD-ROM:

SPATIAL_COVERAGE,DATE_OBS,START_TIME,END_TIME,PLATFORM, INSTRUMENT,NUM_BANDS,

BAND QUALITY, CLOUD COVER,NUM VIS IMAGES,NUM IR2 IMAGES,NUM IR3 IMAGES,

NUM_IR4_IMAGES,NUM_IR5_IMAGES,CRTFCN_CODE

'REGION', 14-JUL-95,15,2345, 'GOES-8', 'GOES I-M Imager',3, 'NOT ASSESSED',

'NOT ASSESSED',I,,I,I,,'CPI'

'REGION',I5-JUL-95,15,2345, 'GOES-8', 'GOES I-M Imager',3, 'NOT ASSESSED',

'NOT ASSESSED',48,,48,48,, 'CPI'

8. Data Organization

8.1 Data Granularity

The smallest unit of data for level-la GOES-8 image data is a single level-la 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.

8.2 Data Format(s)

The CD-ROM inventory listing file consists of numerical and character fields of varying length

separated by commas. The character fields are enclosed with single apostrophe marks. There are no

spaces between the fields.

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

• ASCII header file

• Visible image data file

• IR4 image data file

• IR3 image data file

Page 19
Onedayof level-laGOES-8datafrom 1996iscontainedin sixphysicaltapefiles:

• ASCIIheaderfile

• Visibleimagedatafile

• IR2imagedatafile

• IR4imagedatafile

• IR5imagedatafile

• IR3imagedatafile

TheASCIIheaderfile contains80-byteASCIIrecordsthatdescribethelevel-la product,provide

summaryanddetailedinformationaboutthe'good'andzero-filledimagesfor thegivenday,and

containdescriptiveheaderinformationextractedfromthevisible,IR2,IR4,IR5,andIR3images.

Notethatthedatasetconsistedof threebandsin 1995andchangedto fivebandsin 1996.In

addition,thesizeof theimagesalsochangedduring1995and1996.Thefollowingtabledescribesthe

changes,andthefollowingparagraphsgivedetailsof thebinarydataformats.

Number Number Number

Start Date End Date Band of Bits of Lines of Pixels

14-Jui-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-Apt-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-Ju1-1995 to 29-Ju1-1995)

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-la 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

Page 20
256valuesof 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- I a 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 dally 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.

Page 21
OneGOES-8IR3 imagecontains512unsigned8-bitcounts(i.e.,valuesfrom0 to 255)storedin

unsigned8-bit(1-byte)valuesin eachof 256lines.A full dayof IR3imagedataconsistsof 48

half-hourlyimages.TheIR3imagedatafileontapecontainsafull dayof imagedata.EachIR3image

datafile ontapeconsistsof 384recordsof 16,384bytes.Eachtaperecordcontains32IR3 imagelines

of 512bytes(16,384= 32* 512).Therefore,oneIR3imageis containedin eighttaperecords(8= 256

/32). The sequence of image times in the file is 0015, 0045, 0115, 0145, 2315, 2345 GMT. Ifa 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-la 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 LR2 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-1 a product contains a set of 256 records

containing 512 16-bit values of 0. The presence of these zero-filIed 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

Page 22
datafile 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-la 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-1 a 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 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 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

Page 23
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 1,2:24 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-1 a 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-la 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-1 a 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.

Page 24
Thesetof 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.

9.1 Formulae

None.

9. Data Manipulations

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-la

products. The processing included:

• Separating the header record and image data records contained in level-1 GOES image files.

• Unpacking the header record information for use in processing control and output to the

level-1 a ASCII header file.

• Writing the four files for each day's data to disk.

• Copying a 4-week period of daily files to tape.

• Appending the reference latitude and longitude files to the tapes.

9.2.2 Processing Changes

None.

Page 25
9.3 Calculations

See Section 9.2.1.

9.3.1 Special Corrections/Adjustments

See Section 9.2.1.

9.3.2 Calculated Variables

See Section 9.2.1.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

The level-la 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-1 a 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 9.2.1.

11.1 Limitations of the Data

Not available at this revision.

1 1. Notes

Page 26
11.2 Known Problems with the Data

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

• 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.

• The ASCII header files for the level-la 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.

None.

13. Future Modifications and Plans

14. Software

14.1 Software Description

BORIS staff developed software and command procedures for:

• Extracting header information from level GOES-8 images on tape and writing it to ASCII files

on disk for initial quality checking.

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

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

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

• 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. BORIS staff would appreciate knowing of

any problems discovered with the software, but cannot guarantee that they will be fixed.

Page 27
15. Data Access

The level- 1a GOES-8 images are available from the Earth Observing System Data and Information

System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center

(DAAC).

15.1 Contact Information

For BOREAS data and documentation please contact:

ORNL DAAC User Services

Oak Ridge National Laboratory

P.O. Box 2008 MS-6407

Oak Ridge, TN 37831-6407

Phone: (423) 241-3952

Fax: (423) 574-4665

E-mail: omldaac@ornl.gov or oml@eos.nasa.gov

15.2 Data Center Identification

Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory

(ORNL) Distributed Active Archive Center (DAAC) for Biogeochemical Dynamics

http://www-eosdis.ornl.gov/.

15.3 Procedures for Obtaining Data

Users may obtain data directly through the ORNL DAAC online search and order system

[http://www-eosdis.ornl.gov/] and the anonymous FTP site [ftp://www-eosdis.oml.gov/data/] or by

contacting User Services by electronic mail, telephone, fax, letter, or personal visit using the contact

information in Section 15.1.

15.4 Data Center Status/Plans

The ORNL DAAC is the primary source for BOREAS field measurement, image, GIS, and

hardcopy data products. The BOREAS CD-ROM and data referenced or listed in inventories on the

CD-ROM are available from the ORNL DAAC.

16. Output Products and Availability

16.1 Tape Products

The level-la 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

Although the inventory is contained on the BOREAS CD-ROM set, the actual level-1 a GOES-8

images are not. See Section 15 for information about how to obtain the data.

Page 28
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. Desorrneaux, 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

Newcomer, J., D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson,

A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers, eds. 2000. Collected Data of The

Boreal Ecosystem-Atmosphere Study. NASA. CD-ROM.

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.

Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M. Ryan, K.J. Ranson, P.M.

Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J. Newcomer, D. Fitzjarrald, P.G. Jarvis, S.T.

Gower, D. Halliwell, D. Williams, B. Goodison, D.E. Wickland, and F.E. Guertin. 1997. BOREAS

in 1997: Experiment Overview, Scientific Results and Future Directions. Journal of Geophysical

Research 102(D24): 28,731-28,770.

17.3 Archive/DBMS Usage Documentation

None.

None.

18. Glossary of Terms

Page 29
19. List of Acronyms

AOCS

ASCII

ATS

BB

BOREAS

BORIS

BPI

CCT

CDA

CD-ROM

DAAC

DAT

DC

DN

ECAL

EOS

EOSDIS

ESD

E-W

FFC

.FSU

- Attitude and Orbit Control System

- American Standard Code for Information Interchange

- Application Technology Satellite

- Blackbody

- BOReal Ecosystem-Atmosphere Study

- BOREAS Information System

- Bytes Per Inch

- Computer Compatible Tape

- Command and Data Acquisition

- Compact Disk-Read-Only Memory

- Distributed Active Archive Center

- Digital Archive Tape

- Dark Current

- Digital Number

- Electronic Calibration

- Earth Observing System

- EOS Data and Information System

- Environmental Satellite Data, Inc.

- East-West

- Focused Field Campaign

- Florida State University

GIMTACS - GOES I-M Telemetry and Command System

GIS

GMT

GOES

GSFC

GVAR

I/O

IFC

IFOV

IGFOV

IMC

INR

IR

ISLSCP

MMC

NAD83

NASA

NESDIS

NLUT

NOAA

N-S

NSA

NWS

OAT S

OGE

ORNL

PA]qP

PM

PMS

RSS

SDI

- Geographic Information System

- Greenwich Mean Tim

- Geostationary Operational Environmental Satellite

- Goddard Space Flight Center

- GOES VARiable

- Input/Output

- Intensive Field Campaign

- Instantaneous Field of View

- Instantaneous Geometric Field of View

- Image Motion Compensation

- Instrument Navigation & Registration

- Infrared

- International Satellite Land Surface Climatology Project

- Mirror Motion Compensation

- North American Datum of 1983

- National Aeronautics and Space Administration

- National Environmental Satellite, Data and Information Service

- Normalization Look-Up Table

- National Oceanic and Atmospheric Administration

- North-South

- Northern Study Area

- National Weather Service

- Orbit and Altitude Tracking System

- Operations Ground Equipment

- Oak Ridge National Laboratory

Prince Albert National Park

- Product Monitor

Performance Monitoring System

Remote Sensing Science

- Sensor Data Interface

Page 30
SEM

SMS

SPS

SS/L

SSA

T&C

URL

VAS

VISSR

- Space Environmental Monitoring

- Synchronous Meteorological Satellites

- Sensor Processing Subsystem

- Space Systems/Loral, Inc.

- Southern Study Area

- Telemetry and Command

- Uniform Resource Locator

- VISSR Atmospheric Sounder

- Visible and Infrared Spin Scan Radiometer

20. Document Information

20.1 Document Revision Dates

Written: 25-Jul- 1995

Last Updated: 06-Ju1-1999

20.2 Document Review Dates

BORIS Review: 24-Apt-1998

Science Review:

20.3 Document ID

20.4 Citation

When using these data, please include the following acknowledgment as well as citations of

relevant papers in Section 17.2:

The level- I a 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.

Also, cite the BOREAS CD-ROM set as:

Newcomer, J., D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J.

Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers, eds. Collected Data of

The Boreal Ecosystem-Atmosphere Study. NASA. CD-ROM. NASA, 2000.

20.5 Document Curator

20.6 Document URL

Page 31
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instroctions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this

collection o1 information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

i

1. AGENCY USE ONLY (Leave btank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

August 2000 Technical Memorandum

4. TITLE AND SUBTITLE

Technical Report Series on the Boreal Ecosystem-Atmosphere Study (BOREAS)

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

6. AUTHOR(S)

Jeffrey A. Newcomer, David Faysash, Harry J. Cooper, and Eric A. Smith

Forrest G. Hall, Editor

7.PERFORMINGORGANIZATIONNAME(S)ANDADDRESS(ES)

Goddard Space Flight Center

Greenbelt, Maryland 20771

9. SPONSORING/ MONITORINGAGENCYNAME(S)AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

5. FUNDING NUMBERS

923

RTOP: 923-462-33-01

8. PEFORMING ORGANIZATION

REPORT NUMBER

2000-03136-0

10. SPONSORING / MONITORING

AGENCY REPORT NUMBER

TM--2000-209891

Vol. 66

11.SUPPLEMENTARYNOTES

J.A. Newcomer: Raytheon ITSS; D. Faysash, H.J. Cooper, and EA. Smith: Florida State University

12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

Unclassified-Unlimited

Subject Category: 43

Report available from the NASA Center for AeroSpace Information,

7121 Standard Drive, Hanover, MD 21076-1320. (301) 621-0390.

13. ABSTRACT (Maximum 200 words)

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-la GOES-8 images were created by BORIS personnel from the level-1 images delivered

by FSU personnel. The data cover 14-Ju1-1995 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-I a GOES-8 data are the formatting and packaging of

the data. The images missing from the temporal series of level-I 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 f'de, 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.

Note: Due to the large size of the images, the level-la GOES-8 data are not contained on the BOREAS CD-ROM set. An

inventory listing file is supplied on the CD-ROM to inform users of what data were collected. The level-la GOES-8 image

data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). Spe sections 15 and 16 for more information.

i

14. SUBJECT TERMS

BOREAS, remote sensing science, GOES-7 and -8.

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

NSN 7540-01-280-5500

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15. NUMBER OF PAGES

31

16. PRICE CODE

20. LIMITATION OF ABSTRAC1

UL

Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. Z39.t8

298-102