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LANDSAT ORTHORECTIFIED PANSHARPENED ETM+ IMAGERY (LANDSAT_ORTHO_PAN_ETM+) PRODUCT README

TABLE OF CONTENTS

• Compact Disc Organization
• Naming Convention
• Directory and File Descriptions
• Background
• Data Set Characteristics
• Procedures
• Processing
• Restrictions
• USGS Contact
• References
• Appendices
• Approximate File Sizes
• Sample FGDC Compliant Landsat-7 ETM+ Metadata:

Compact Disc Organization

Naming Convention

File Conventions are compliant with ISO-9660 Level-1 standards (8.3 file naming convention) and also compliant with ISO-9660 standards with Joliet extensions (permits file names greater than 8.3 and permits the use of lowercase characters).

File Descriptions

The granules on the LANDSAT_ORTHO_PAN_ETM+ compact disc contains README files, an Object Description Language metadata file, a Sample FGDC Compliant Landsat-7 ETM+ Metadata file, and Landsat image files. The number of image files per granule may vary.

README.TXT: Self explanatory.

README.PDF: Self explanatory.

SAMPLE FGDC COMPLIANT LANDSAT-7 PANSHARPENED ETM+ METADATA: Self explanatory.

METADATA: ODL: Self explanatory.

IMAGE: 1 image using bands 7, 4, 2.

BROWSE: Image of the scene ordered.

File Naming Convention (Browse, Metadata, and Image Files):

/pppprrrr_isyyyymmdd_zzx_nnnx

EXAMPLE:     /p158r75_7t20000702_z58_nn62

pppp: Path Indicator (4 characters)

p = path

Example:       p158

rrrr: Row Indicator (4 character maximum, not zero filled)

r = row

Example:       r75

_: Delimiter (1 character)

i: Instrument Indicator (1 character)

Values:

7 = Landsat-7

s: Sensor Type (1 character: where valid parameters are "t", "p" and "k")

Values:

t = 28.5 multi-spectral data (6 bands)

p = 14.25 meter pan data (1 band)

k = 57 meter thermal data (2 bands)

yyyymmdd: Acquisition Date (8 characters)

Values:

y = Year

m = Month

d = Day

Example:       20000702

_: Delimiter (1 character)

z: UTM Zone Indicator (1character)

Values:

z = indicator

zx: UTM Zone Number (1-3 characters, not zero filled)

Example:       58

_: Delimiter (1 character)

ps742: Constant Value: pansharpened using bands 7, 4, 2

Sample file name in its entirety reads as follows:

/p158r75_7t20000702_z58_nn62

Background

Data were compiled through NASA's Commercial Remote Sensing Program; this program is a cooperative effort between NASA and the commercial and the commercial remote sensing community to provide users with access to quality-screened, high-resolution satellite images with global coverage over the Earth's land masses. The resulting Landsat Enhanced Thematic Mapper Plus (ETM+) data set contains orthorectified ETM+ sensor data from the Landsat-7 satellite. Only the ETM+ images most closely meeting a specific set of criteria, including acquisition date, cloud percentage, data quality parameters, and best available phenology, were considered for this collection. The Landsat ETM+ data were provided by the USGS and orthorectified through a NASA contract with Earth Satellite Corporation, Rockville, Maryland, and are part of NASA's Scientific Data Purchase program, developed in response to the President's Space Policy. The Landsat Orthorectified Pansharpened ETM+ data set possesses additional processing via pansharpening. This process, also known as resolution merging, fuses together the high-resolution panchromatic and lower-resolution multispectral imagery to create a high-resolution color image. Pansharpened data retain as much of the spectral information as is possible from the multiband raster image. The resulting high-resolution color image preserves the original color fidelity and allows for better visualization, interpretation, and clarity.

Data Set Characteristics

Approximately 8,500 Landsat ETM+ images were selected. These circa year 2000 scenes were acquired between 1999 and 2001, and have been orthorectified so as to tightly co-register with the earlier circa 1990 global Landsat TM coverage. NOTE: In both the circa 1990 and circa 2000 data sets, the temporal dates of individual scenes may vary between 1-3 years of the 1990/2000 baseline.) These images were either cloud-free or contained minimal cloud cover. In addition, only ETM+ images with a high quality ranking in regards to the possible presence of errors such as missing scans or saturated bands were selected. It was important to collect data during periods of peak greenness so NASA adopted an approach for image selection that was based upon a data set containing global 1-kilometer advanced very high-resolution radiometer Normalized Difference Vegetation Index data. It was sometimes difficult for NASA to obtain clear images during time frames of peak greenness, resulting in some image substitution from other times of the year.

Procedures

Processing

Landsat ETM+ data are orthorectified using existing orthorectified TM data as horizontal control. Pixel cross-correlation is used to pass the control from the earlier orthorectified TM data to the Landsat ETM+. A patented Landsat large block triangulation procedure is used to perform a photogrammetric adjustment of each individual Landsat ETM+ scene; data are then placed into a UTM / WGS84 map projection. All bands are individually re-sampled, using a nearest neighbor algorithm. The result is a final image map product with a Root Mean Square Error (RMSE) of better than 50 meters in positional accuracy.

The Landsat ETM+ scenes were then pansharpened using a resolution merging process allowing the high-resolution panchromatic and lower-resolution multispectral imagery to fuse together to create a single high-resolution color image. This process allows the image to retain as the greatest value of the spectral information as possible from the multiband raster image. The resulting high-resolution color image preserves the original color fidelity and allows for better visualization, interpretation, and clarity.

Restrictions

No restrictions.

USGS Contact

References

Kalluri, Satya, Grant, Denelle, Tucker, Compton, Policelli, Fritz, Dykstra, Jon, and Bearden, Phil, 2000, NASA creates global archive of ortho-rectified Landsat data: EOS, Transactions, American Geophysical Union, v. 81, no. 50, p. 609, 617-618.

Dykstra, Jon D., Jan/Feb 2001, The GeoCover-Ortho Program: Covering the Entire Earth's Landmass with 14,000 Landsat Images; GEO INFORMATICS, p. 26-29. Reference is available in PDF format.

Appendices

Approximate File Sizes:

FILE TYPE			FILE SIZE: (kilobytes)
Metadata File: ODL		6
Image File:			880,000
ReadMe File: text		9
ReadMe File: pdf		109

Sample FGDC Compliant Landsat-7 ETM+ Pansharpened Metadata:

GROUP = METADATA_FILE
	PRODUCT_CREATION_TIME = 2002-06-23T05:32:08Z
	PRODUCT_FILE_SIZE = 861.6
	STATION_ID = "EDC"
	GROUND_STATION = "EDC"
	GROUP = COLOR_ETM+_PANSHARPENED_ORTHO_PRODUCT_METADATA
		SPACECRAFT_ID = "Landsat7"
		SENSOR_ID = "ETM+"
		ACQUISITION_DATE = 2000-08-25
		WRS_PATH = 110
		WRS_ROW = 011
		SCENE_CENTER_LAT = +69.9189433
		SCENE_CENTER_LON = +153.7613467
		SCENE_UL_CORNER_LAT = +70.7353245
		SCENE_UL_CORNER_LON = +151.3250550
		SCENE_UR_CORNER_LAT = +70.7121089
		SCENE_UR_CORNER_LON = +156.3660343
		SCENE_LL_CORNER_LAT = +69.0901982
		SCENE_LL_CORNER_LON = +151.3506209
		SCENE_LR_CORNER_LAT = +69.0716900 
		SCENE_LR_CORNER_LON = +156.0117110
		SCENE_UL_CORNER_MAPX = 438330.000
		SCENE_UL_CORNER_MAPY = 7848729.000
		SCENE_UR_CORNER_MAPX = 624036.000 
		SCENE_UR_CORNER_MAPY = 7848729.000
		SCENE_LL_CORNER_MAPX = 434311.500
		SCENE_LL_CORNER_MAPY = 7665303.000
		SCENE_LR_CORNER_MAPX = 620017.500
		SCENE_LR_CORNER_MAPY = 7665303.000
		FILE_NAME = "p110r011_7t20000825_z56_ps742.tif"
		GROUP = PROJECTION_PARAMETERS
			REFERENCE_DATUM = "WGS84"
			REFERENCE_ELLIPSOID = "WGS84"
			GRID_CELL_ORIGIN = "Center"
			UL_GRID_LINE_NUMBER = 1
			UL_GRID_SAMPLE_NUMBER = 1
			GRID_INCREMENT_UNIT = "Meters"
			GRID_CELL_SIZE_CPS = 14.250
			FALSE_NORTHING = 0
			ORIENTATION = "NUP"
			RESAMPLING_OPTION = "CC"
			MAP_PROJECTION = "UTM"
		END_GROUP = PROJECTION_PARAMETERS
		GROUP = UTM_PARAMETERS
			ZONE_NUMBER = +56
		END_GROUP = UTM_PARAMETERS
		GROUP = ETM+ SPECTRAL_INPUTS
			GROUP = INPUT_MSI
				ETM+_ORTHO = “p110r011_7t20000825”
				RED_INPUT = “BAND7”
				GREEN_INPUT = “BAND4”
				BLUE INPUT = “BAND2”
			END_GROUP = INPUT_MSI
			GROUP = INPUT_PAN
				ETM+_PAN = “p110r011_7p20000825”
				PAN_INPUT = “BAND8”
			END_GROUP = INPUT_PAN
		END_GROUP = ETM+_SPECTRAL_INPUTS
		PANSHARPENING_TECHNIQUE = “LINEAR COMBINATION”
		DYNAMIC_RANGE_ADJUSTMENT = “NONE”
		SUN_AZIMUTH = 171.8285261
		SUN_ELEVATION = 30.9211359
		QA_PERCENT_MISSING_DATA = 93
		CLOUD_COVER = 80
		PRODUCT_SAMPLES_CPS = 19212
		PRODUCT_LINES_CPS = 17902
		OUTPUT_FORMAT = "GEOTIFF"
	END_GROUP = COLOR_ETM+_PANSHARPENED_ORTHO_PRODUCT_METADATA
END_GROUP = METADATA_FILE
END