Hyperion

Long name EO1 Hyperion
Short name HYP
Sensor type Hyperion hyperspectral imager including the following spectrometers:
  • Visible and near infrared (VNIR)
  • Shortwave infrared (SWIR)
Platform Earth observation
Key file name (use to open data set)

EO1H*.txt
- or -
EO1H*.met

Supported file name extensions .txt, .tif, .met, .L1R, .hdr
Sections

Data product name and description
Distribution disk files
Returned data for supported format
References

Data product name and description

The Earth Observing-1 (EO-1) satellite was launched November 21, 2000 as a one-year technology demonstration and validation mission. After the initial technology mission was completed, NASA and the USGS agreed to the continuation of the EO-1 program as an Extended Mission. The EO-1 Extended Mission is chartered to collect and distribute Hyperion hyperspectral and Advanced Land Imager (ALI) multispectral products according to customer-tasking requests.

The Hyperion imaging instrument provides radiometrically calibrated spectral data. The purpose of the data is to support evaluation of hyperspectral technology for Earth-observing missions. Hyperion is a pushbroom, imaging spectrometer. Each ground image contains data for a region 7.65 km wide (cross-track) by 185 km long (along-track). Each pixel covers an area of 30 m by 30 m on the ground, and a complete spectrum covering 357 - 2576 nm with a ~10-nm bandwidth is collected for each pixel. Because Hyperion is a pushbroom system, the entire 7.65 km-wide swath is obtained in a single frame. The 30 m size in the along-track direction was obtained by basing the frame rate on the velocity of the spacecraft for a 705 km orbit.

Note: The information provided herein is based on the data distributor's documentation cited under References.

Spectral bands:
Spectral range (nm)

Spatial resolution (m)*
(spectral resolution)

Maximum image dimensions
(Across track x along track, km)

Notes

VNIR: 350 - 1064
SWIR: 846 - 2582

30 x 30 7.65 x 1855 Channels 1 through 70 are collected with the VNIR spectrometer.

Channels 71 through 242 are collected with the SWIR spectrometer.

There is a one-pixel shift between the VNIR and SWIR cross track coregistration, resulting in a 255 VNIR-SWIR coincident field-of-view location. Due to low signal for some channels, and to reduce the VNIR-SWIR overlap region, some of these spectral channels are not calibrated. The uncalibrated channels are set to zero. The channels are not removed from the file so that the final data set is the same size as the initial data set.

* Resolution is always nadir position unless noted otherwise.

The Hyperion product types tested and supported by PCI software are described in the following table.

Product level Horizontal accuracy (m) Description/notes
1GST N/A Radiometric and systematic geometric corrections derived from spacecraft ephemeris data have been applied while employing a 90-meter digital elevation model (DEM) for topographic accuracy.

Scenes are provided in GeoTIFF format.

1R N/A Radiometric corrections to compensate for variations due to detector sensitivity.

This processing level is only available for Hyperion data.

Products are provided in Hierarchical Data Format (HDF).

1T N/A Radiometric and systematic geometric corrections incorporating ground control points (GCP) have been applied while employing a 90-meter DEM for topographic accuracy.

Geodetic accuracy of the product depends on the accuracy of the GCPs and is expected to be within two pixels.

Scenes that do not have adequate ground control will be processed to the best level of correction (L1Gst).

Scenes are provided in GeoTIFF format.

Distribution disk files

Hyperion data sets are organized in a specific folder structure on disk. GDB uses this folder structure and the file names to identify the data product. Therefore, to preserve compatibility with GDB, do not alter the folder structure and file names when copying and decompressing the data.

You can open a Hyperion data set by selecting the relevant file according to the product level, as follows.

Product level File to select
1R eo1h*.met
1GST, 1T eo1h*.txt

The file naming convention is as follows, where the sample file name is EO1SPPPRRRYYYYDDDXXXML_GGG_VV.fgdc.

Character Description
EO1 Satellite
S

Sensor
H: Hyperion
A: ALI

PPP Target WRS path
RRR Target WRS row
YYYY Year of acquisition
DDD Day of acquisition (Julian)
X

Hyperion
0: Off
1: On

X

ALI
0: Off
1: On

X

AC
0: Off
1: On

M

Pointing mode
N: Nadir
P: Pointed within path/row
K: Pointed outside path/row

L

Scene length
F: Full scene
P: Partial scene
Q: Second partial scene
S: Swath

Note: Additional letters may be used as distinct-entity IDs
GGG Ground/receiving station
VV Version number

When opening a Hyperion data set, the files read by GDB are as described in the following table.

File name Format Required Contents/details

L1GST: EO1H*_L1GST.txt
L1R: EO1H*.met
L1T: EO1H*_L1T.txt

Text Yes Key file name, contains data-set metadata

L1GST: EO1H*_Bxxx_L1GST.tif
L1R: EO1H*.L1R
L1T: EO1H*_Bxxx_L1T.tif

GeoTIFF or HDF4 Yes Image data
EO1H*.hdr Band-wavelength data Yes Product L1R only
EO1H*.fgdc Federal Geographic Data Committee Optional Metadata
readme.txt Text Optional N/A

Returned data for supported format

Hyperion data can be opened directly in its raw vendor format or imported into a PCIDSK (*.pix) file using the following key file name for the relevant level:
  • L1GST: EO1H*_L1GST.txt
  • L1R: EO1H*.met
  • L1T: EO1H*_L1T.txt
For optimal processing, use the PCIDSK format.

The following table describes the data structure after it is opened by GDB.

Data product Data returned Details
1GST (Hyperspectral)

242 x [16S] raster channels

1 x [ORB] orbit segment
1 x [TEX] product annotation

Bands 1 through 70 are VNIR.
Bands 71 through 242 are SWIR.
Many VNIR bands overlap with SWIR bands. Overlapping bands are empty (value of all pixels is one). NoData value zero is used for areas that have no data filled.

1R (Hyperspectral)

242 x [16S] raster channels

1 x [ORB] orbit segment
1 x [TEX] product annotation

Bands 1 through 70 are VNIR.
Bands 71 through 242 are SWIR.
Many VNIR bands overlap with SWIR bands. Overlapping bands are empty (value of all pixels is one). NoData value zero is used for areas that have no data filled.

1T (Hyperspectral)

242 x [16S] raster channels

1 x [TEX] product annotation

Bands 1 through 70 are VNIR.
Bands 71 through 242 are SWIR.
Many VNIR bands overlap with SWIR bands. Overlapping bands are empty (value of all pixels is one). NoData value zero is used for areas that have no data filled.

Note: There is no orbit segment, because the data is corrected product.

References

EO-1/Hyperion Science Data User’s Guide, TRW Space, Defense & Information Systems, One Space Park, Redondo Beach, CA, 90278, May 2001.

Presentation: The EO-1 Hyperion Imaging Spectrometer, IEEE Aerospace Conference, Jay Pearlman, Carol Segal, Pamela Clancy, Neil Nelson, Peter Jarecke, Momi Ono, Debra Beiso, Lushalan Liao, Karen Yokoyama, and Steve Carman, TRW and Bill Browne, Lawrence Ong and Stephen Ungar, GSFC.

EO-1/Hyperion Science Data User’s Guide, Level 1_B, TRW Space, Defense & Information Systems, One Space Park, Redondo Beach, CA, 90278, November 2001

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