Urban Landsat: Cities from Space
Entry ID:
CIESIN_SEDAC_URBAN_LANDSAT
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Summary
Abstract:
DATA ACCESS The TOGA COARE Data Information System ( http://lwf.ncdc.noaa.gov/oa/coare/ ) has responsibility for distributing information about TOGA COARE datasets and access paths. The ISCCP DX images and flux data are online and can be obtained from the NASA GSFC DAAC via ftp from daac.gsfc.nasa.gov in subdirectory pub/toga_coare/satellite/isccp/ or via the WWW using the URL ... http://disc.gsfc.nasa.gov/fieldexp/TOGA/sat_link.shtml . To obtain the ISCCP
data on tape, contact the DAAC User Services Office. For help with NASA TOGA
COARE data residing at the GSFC DAAC, contact Pat Hrubiak at
hrubiak@daac.gsfc.nasa.gov.
BACKGROUND
TOGA COARE was a multidisciplinary, international research effort that
investigated the scientific phenomena associated with the interaction
between the atmosphere and the ocean in the warm pool region of the
western Pacific. The field experiment phase of the program took place
from 1 November 1992 through 28 February 1993 and involved the
deployment of oceanographic ships and buoys, several ship and land
based Doppler radars, multiple low and high level aircraft equipped
with Doppler radar and other airborne sensors, as well as a variety of
surface based instruments for in situ observations.
The NASA component of TOGA COARE, while contributing directly to
overall COARE objectives, emphasized scientific objectives associated
with the Tropical Rainfall Measuring Mission (TRMM) and NASA's cloud
and radiation program.
GENERAL INFORMATION
The ISCCP DX and flux dataset consists of analyses of data acquired
from the GMS satellite and the NOAA 11 and 12 satellites in support of
TOGA-COARE. Principal Investigator Bill Rossow of the Goddard
Institute for Space Studies (GISS) subsetted this dataset both
temporally and spatially to conform to the TOGA COARE period and
region.
Temporal Coverage and Resolution: All times are in GMT. The temporal
coverage for the TOGA COARE campaign and for this ISCCP subset is 4
months from 1 November 1992 through 28 February 1993. The sampling
interval for these data is about 3 hr for GMS and 12 hr for each NOAA
polar orbiter.
Spatial Coverage and Resolution: The ISCCP subsets for the TOGA COARE
campaign cover the region:
Longitude: 120E --> 190E
Latitude: 20S --> 20N
The spatial resolution is about 30 km for sensors on all 3 satellites.
ISCCP SCIENCE OBJECTIVES
Investigation of the role of clouds in climate involves a complex
interrelated study of many different processes and addresses many
different questions. The ISCCP's scientific objectives are:
- to produce a global, reduced resolution, infrared and visible,
calibrated and normalized radiance dataset containing basic
information on the radiative properties of the atmosphere from which
cloud parameters can be derived;
- to stimulate and coordinate basic research on techniques for
inferring the physical properties of clouds from the condensed
radiance dataset and to apply the resulting algorithms to derive and
validate a global cloud climatology for improving the parameterization
of clouds in climate models;
-to promote research using ISCCP data and contribute to improved
understanding of the Earth's radiation budget (top of atmosphere and
surface) and hydrological cycle.
General Description: This analysis is based on data from the GMS, NOAA
11 and NOAA 12 satellites;
GMS (Geostationary Meteorological Satellite): Operated by the Japan
Meteorological Agency (JMA), GMS is a spin-stabilized spacecraft
maintained at 140E longitude. Imaging data are from the Visible
Infrared Spin-Scan Radiometer (VISSR), with high resolution (1.25 km)
visible images obtained by four identical detectors scanning in
parallel. The spin-scan is from west to east and from north to south.
The NOAA TIROS-N series satellites are three-axis stabilized in 850 KM
(nominal) circular, near-polar, sun-synchronous orbits with an
inclination angle of approximately 99 degrees (retrograde) to the
equator. The orbital period is about 102 minutes. Sequential orbits
observe adjacent longitudes near the equator and provide overlapping
coverage in both polar regions. The instrument complement is as
follows:
NOAA 11:
- AVHRR, 5 channels
- HIRS/2, 20 channels
- MSU, 4 channels
- SSU, 3 channels
NOAA 12:
- AVHRR, 5 channels
- HIRS/2, 20 channels
- MSU, 4 channels
- SBUV
DATA ORGANIZATION
a) DX Data
General Characteristics: ISCCP DX data are the individual pixel-level
results of the analysis that contain the visible and IR radiances, the
clear-sky radiances, the surface reflectance and temperature from the
clear-sky radiances, the cloud detection decision, and the retrieved
physical quantities. For clear pixels, these are the surface
reflectance and temperature; for cloudy pixels these are the cloud top
temperature/pressure and optical thickness. The cloud top temperature
is obtained with three different models: assuming an opaque cloud (all
times of day), assuming a liquid water cloud or an ice cloud
(daytime).
The ISCCP DX TOGA COARE subset totals 2129 data files and is about
approximately 1.07 GB in volume. Each file contains data for one
GMT. Files are named 'FC_DT_KA.YYMMDDHH' where YY=92, 93 (year),
MM=11, 12, 1, 2 (month), DD=01, 02,.., 31 (date) and HH=00, 03, .. 21
(GMT).
Data Format: Each data file comprises 448 (28 X 16) grid boxes, each
containing 48 1792 byte records corresponding to the 48 parameters.
There are a variable number of data records in each DX image. Each
record contains packed binary pixel data as follows:
I*4 IWEST Western-most longitude (0-3600 degrees*10)
I*4 IEAST Eastern-most longitude (0-3600 degrees*10)
I*4 INORTH Northern-most latitude (0-1800 degrees*10)
I*4 ISOUTH Southern-most latitude (0-1800 degrees*10)
I*4 NPIX Number of pixels
I*4 IOUT Number of bytes in packed data BUFFER
I*2 LONBUF(NPIX) Longitudes for NPIX pixels (0-3600 degrees*10)
I*2 LATBUF(NPIX) Latitudes for NPIX pixels (0-1800 degrees*10)
I*2 XBUF(NPIX) X-positions for NPIX pixels (1-1440)
I*2 YBUF(NPIX) Y-positions for NPIX pixels (1-550)
I*1 BUFFER(IOUT) Packed data for NPIX pixels
remainder of record is filled with I*1 255 values.
The contents of the buffer as it is unpacked are as follows:
NOTE 1: Numbers on the left identify the byte number from 1 to 37.
This is the MAXIMUM number of bytes that a pixel can have. Not all
bytes are present for all pixels.
DATA SECTION 1 - pixel ident. satellite angle, IR cloud detection
1. NODAY,BXSHOR,LNDWTR,HITOPO,SNOICE,TIMSPA (N,B,L,H,SS,TT)
*NODAY : BX day/night flag (0-1), 1 = day sect. 2,4 not present
*BXSHOR : BX shore flag (0-1), 1 = shore pixel
LNDWTR : Land/water flag (0-1), 1 = water pixel
HITOPO : Topography flag (0-1), 1 = high topography pixel
SNOICE : Snow/ice code (0-3)
*TIMSPA : Time/space test result (0-3)
2. ICSLOG,BXITHR (IIIII,BBB)
*ICSLOG : IR clear sky composite logic code (0-24)
*BXITHR : BX IR threshold result ()-5)
3. MUE : Cosine of satellite angle * 100 (0-100)
4. IRAD : IR radiance (0-254 ct)
5.*BXICSR : BX IR clear sky radiance (0-254 ct)
If image header says additional channels are present (BXADDL>0) then:
6. ARAD(1) : First additional channel radiance (0-254 ct)
7. ARAD(2) : Second additional channel radiance (0-254 ct)
8. ARAD(3) : Third additional channel radiance (0-254 ct)
DATA SECTION 2 - sun angles, VIS cloud detection
if NODAY = 0 (day sections present) then:
9. GLINT,VCSLOG,BXVTHR (G,VVVV,BBB)
GLINT : Glint flag (0-1), 1 = glint condition exists
*VCSLOG : VIS clear sky composite logic code (0-14)
*BXVTHR : BX VIS threshold result
10. MU0 : Cosine of sun angle * 100 (0-100)
11. PHI : Relative azimuth angle (0-180 degrees)
12. VRAD : VIS radiance (0-254 ct)
13.*BXVCSR : BX VIS clear sky radiance (0-254 ct)
DATA SECTION 3 - adjusted cloud detections, IR retrievals,
additional channel cloud detections
14. DAYNIT,ITHR,VTHR,SHORE (D,III,VVV,S)
DAYNIT : Day/night flag (0-1), 1 = night pixel (no VIS retrieval
ITHR : IR threshold result (0-5)
VTHR : VIS threshold result (0-5)
SHORE : Shore flag (0-1), 1 = shore pixel
15. IRET,ICSRET (IIII,IIII)
*IRET : IR retrieval code (0-12)
*ICSRET : IR clear sky composite retrieval code (0-12)
16. ICSRAD : IR clear sky composite radiance (0-254 ct)
17. ITMP : IR retrieved cloud top or surface temperature (0-254 ct)
18. IPRS : IR retrieved cloud top pressure (0-254 ct)
19. ICSTMP : IR retrieved clear sky composite temperature (0-254 ct)
20. ICSPRS : IR retrieved clear sky composite pressure (0-254 ct)
if image header says is polar (SATTYP = 1,2,or -3) then:
21. NREF : NI reflectivity (NOAA channel 3) (0-254 ct)
22. NTHR : NI threshold result (NOAA channel 3) (0-254 ct)
23. NCSREF : NI clear sky composite reflectance (NOAA channel 3)
DATA SECTION 4 - VIS retrievals
if NODAY = 0 (day sections present) then:
if DAYNIT = 1 (night, no VIS retrievals) these will all be 255
24. VRET,VCSRET (VVVV,VVVV)
*VRET : VIS retrieval code (0-14)
*VCSRET : VIS clear sky composite retrieval code (0-14)
25. VCSRAD : VIS clear sky composite radiance (0-254 ct)
26. VALBTA : VIS retrieved cloud tau or surface albedo (0-254 ct)
27. VCSALB : VIS retrieved clear sky composite albedo (0-254 ct)
28. VTMP : VIS adjusted cloud top temperature (0-254 ct)
29. VPRS : VIS adjusted cloud top pressure (0-254 ct)
30. VTAUIC : VIS retrieved ice cloud tau (0-254 ct)
31. VTMPIC : VIS retrieved ice cloud top temperature (0-254 ct)
32. VPRSIC : VIS retrieved ice cloud top pressure (0-254 ct)
b) Flux data
General Characteristics: The ISCCP Flux TOGA COARE subset consists of
953 binary data files and is approximately 78.2 MB in volume. Files
are named 'FC_DT_KA.YYMMDDHH' where YY=92, 93 (year), MM=11, 12, 1, 2
(month), DD=01, 02,.., 31 (date) and HH=00, 03, .. 21 (GMT).
Data Format: Each fixed-length data file is for one GMT and contains
48 1792-byte records, each corresponding to one of the following
parameters, ordered here by direct access record numbers used in the
read program:
(1) SW downwelling at TOA;
(2) SW upwelling at TOA;
(3) SW downwelling at SRF;
(4) SW upwelling at SRF;
(5) LW upwelling at TOA;
(6) LW upwelling at SRF;
(7) LW downwelling at SRF;
(8) SW upwelling at TOA for 100% overcast;
(9) SW downwelling at SRF for 100% overcast;
(10) SW upwelling at SRF for 100% overcast;
(11) LW upwelling at TOA for 100% overcast;
(12) LW upwelling at SRF for 100% overcast;
(13) LW downwelling at SRF for 100% overcast;
(14) SW upwelling at TOA for clear sky;
(15) SW downwelling at SRF for clear sky;
(16) SW upwelling at SRF for clear sky;
(17) LW upwelling at TOA for clear sky;
(18) LW upwelling at SRF for clear sky;
(19) LW downwelling at SRF for clear sky;
(20) Cosine solar zenith angle (0 --> 1);
(21) Cloud fraction (0 --> 1);
(22) Cloud top T (K);
(23) Cloud TAU;
(24) Surface T (K);
(25) Surface reflectance form D1/C2;
(26) Actually used surface reflectance;
(27) Surface air T (K);
(28) Cloud top pressure (mb);
(29) Cloud base pressure (mb);
(30) Surface pressure (mb);
(31) T at 900 mb;
(32) T at 740 mb;
(33) T at 620 mb;
(34) T at 500 mb;
(35) T at 375 mb;
(36) T at 245 mb;
(37) T at 115 mb;
(38) Pressure of tropopause;
(39) T at tropopause;
(40) T at 50 mb of stratosphere;
(41) T at 15 mb of stratosphere;
(42) Precipitable water (cm) for layer of 900 mb;
(43) Precipitable water (cm) for layer of 740 mb;
(44) Precipitable water (cm) for layer of 620 mb;
(45) Precipitable water (cm) for layer of 500 mb;
(46) Precipitable water (cm) for layer of 375 mb;
(47) Column ozone amount (Dobson);
(48) Total precipitable water (cm) for all 5 tropospheric layers.
SOFTWARE
- for dx data: Fortran 77 program DXREAD.f was provided by
the data producer to read the ISCCP DX files. This software is
copiously documented and complete, except for output statements which
should be supplied by the user to extract the desired parameters. It
compiles and runs without modification on the DAAC's SGI equipment
under IRIX 4.0.5C.
- for flux data: Fortran 77 code was provided by the data producer to
read the ISCCP Flux data files. 
Related URL
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Description:
Access dataset ISCCP_DX.
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Geographic Coverage
(Click for Interactive Map)
Spatial coordinates
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N: 70.0
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S: -70.0
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E: 180.0
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W: -180.0
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Quality
No warranty is made as to the accuracy, reliability, and completeness of these
data for individual use or aggregate use with other data. Original data were
compiled from various sources. Spatial information may not meet National
Accuracy Standards. This information may be updated without notification.
Distribution
Distribution Media:
Online
Fees:
No fees
Personnel
Role:
SERF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
Creation and Review Dates
SERF Creation Date:
2003-05-22
SERF Last Revision Date:
2012-02-03
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