The Landsat 7 Processing System
( LPS )
Level Zero-R Science Products
Michael R. Reid
Computer Sciences Corporation
Mike.R...
The Landsat 7 Mission
•
•
•
•
•
•
•

The latest in the Landsat series
Joint operation between NASA and USGS
Global coverag...
Earth Coverage
• Enhanced Thematic Mapper Plus (ETM+) is
the only science instrument
– Images the Earth in 185 km wide swa...
The ETM+ Instrument Data
• Eight bands
– Six 30m-resolution spectral bands
•
•
•
•

Bands 1-5 (range λ = 0.45…1.75 µm)
Ban...
Landsat 7 Processing System (LPS)
• Developed at NASA/GSFC for the EDC
• Part of the Landsat 7 Ground System
• Performs th...
LPS Processing
• Divides the subintervals into sets of contiguous
WRS scenes
• Geolocates the scenes
• Produces viewable, ...
The LPS Moving Window Display (MWD)

ESDIS HDF-EOS Workshop IV
Landover, Maryland, September 20, 2000

7
LPS Processing continued…
• Receives data on two channels (“format 1” and
“format 2”)
• Decodes the downlinked raw telemet...
The LPS Data Products
• LPS products generated on a subinterval basis
• Format 1 and Format 2 are separate file sets
• The...
The Band Files — Swaths
• Image data stored in HDF-EOS Swaths
– One Swath per file
• Bands 1-5 & 7 files are up to about 1...
The Band Files — Geolocation
• Geolocation structures
– Uses HDF-EOS Index map to link WRS scene
corner lon/lat coordinate...
The Internal Calibrator (IC) Files
• Contain lamp and shutter data for spectral
bands
• Contain blackbody radiance and shu...
Mirror Scan Correction Data (MSCD) Files
• Mainly contain data quality information
• Stored in an HDF-EOS Point
• Located ...
Other LPS Product Files
• Payload Correction Data (PCD) Files
– Contain spacecraft attitude and ephemeris information and
...
LPS Browse File (Hudson Bay)

ESDIS HDF-EOS Workshop IV
Landover, Maryland, September 20, 2000

15
Format 1
• Six Band files
– Bands 1-5 and 6L

•
•
•
•

One Internal Calibrator (IC) data file
One Payload Correction Data ...
Format 2
• Three Bands, up to five files
– Bands 6H and 7
– Band 8 (High-Resolution Panchromatic Band)
• Written to up to ...
The LPS Product File Set

ESDIS HDF-EOS Workshop IV
Landover, Maryland, September 20, 2000

18
Level Zero-R Data Subsets
• Single WRS scene products
– One 375 scan subset
– Data fitted to the WRS grid

• Multiple scen...
Subsetting the LPS Subintervals
• LPS Band and IC files contain geolocated HDF-EOS
Swaths
– Can subset band data by index-...
LPS Subsetting Difficulties
• Band data Swaths are stored in separate files
• Format 1/Format 2 data offset
• Partial subi...
Band 8 Subsetting Problem
• Must treat the band 8 segments as completely
separate data sets
• Subsetting out multiple scen...
Level Zero-R Distribution Product
• Native HDF, no HDF-EOS structures
• Contains data from both Format 1 and Format
2
• Su...
L0R Distribution Product File Set

ESDIS HDF-EOS Workshop IV
Landover, Maryland, September 20, 2000

24
Upcoming SlideShare
Loading in …5
×

The Landsat 7 Processing System (LPS) Level Zero-R Science Products

894 views

Published on

Source:http://hdfeos.org/workshops/ws04/presentations/Reid/HDFEOS_IV.ppt

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
894
On SlideShare
0
From Embeds
0
Number of Embeds
6
Actions
Shares
0
Downloads
18
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

The Landsat 7 Processing System (LPS) Level Zero-R Science Products

  1. 1. The Landsat 7 Processing System ( LPS ) Level Zero-R Science Products Michael R. Reid Computer Sciences Corporation Mike.Reid@gsfc.nasa.gov ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 1
  2. 2. The Landsat 7 Mission • • • • • • • The latest in the Landsat series Joint operation between NASA and USGS Global coverage in 8 bands Sun-synchronous orbit Landsat 7 successfully launched in April 1999 Now fully operational Data products provided by the USGS’ EROS Data Center (EDC) in Sioux Falls, SD ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 2
  3. 3. Earth Coverage • Enhanced Thematic Mapper Plus (ETM+) is the only science instrument – Images the Earth in 185 km wide swaths – Images in eight bands • Image data are fitted onto the Worldwide Reference System (WRS) grid – WRS grid consists of 185 km × 170 km scenes – ETM+ images a WRS scene with 375 scans • WRS scenes overlap ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 3
  4. 4. The ETM+ Instrument Data • Eight bands – Six 30m-resolution spectral bands • • • • Bands 1-5 (range λ = 0.45…1.75 µm) Band 7 (λ = 2.09-2.35 µm) 6,600 pixels per scan data line 16 data lines per scan – One 60m-resolution thermal band • Band 6 (λ = 10.4-12.5 µm) • 3,300 pixels per scan data line • 8 data lines per scan – One 15m-resolution panchromatic band • Band 8 (λ = 0.52-0.90 µm) • 13,200 pixels per data line • 32 data lines per scan ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 4
  5. 5. Landsat 7 Processing System (LPS) • Developed at NASA/GSFC for the EDC • Part of the Landsat 7 Ground System • Performs the first stage of Level 0 processing – Aligns bands (forward and reverse scans) – Does not apply corrections or calibrations – Does not perform rectification • Produces HDF-EOS science data products on a subinterval basis • Runs on a high-end SGI™ system ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 5
  6. 6. LPS Processing • Divides the subintervals into sets of contiguous WRS scenes • Geolocates the scenes • Produces viewable, multi-band, color browse images on a WRS scene basis • Performs automatic cloud cover assessment (ACCA) on a WRS scene basis • Displays a Moving Window Display to the user ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 6
  7. 7. The LPS Moving Window Display (MWD) ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 7
  8. 8. LPS Processing continued… • Receives data on two channels (“format 1” and “format 2”) • Decodes the downlinked raw telemetry • Processes the two formats separately • Constructs an image in each band of the “swath” on the Earth’s surface covered during a contact • Divides the swath into subintervals ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 8
  9. 9. The LPS Data Products • LPS products generated on a subinterval basis • Format 1 and Format 2 are separate file sets • The LPS Product file sets include: – – – – – – Band files (Swath files) Internal Calibrator (IC) data files Mirror Scan Correction Data (MSCD) files Payload Correction Data (PCD) files Metadata files Multi-Band Browse files (format 1 only) ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 9
  10. 10. The Band Files — Swaths • Image data stored in HDF-EOS Swaths – One Swath per file • Bands 1-5 & 7 files are up to about 1.2 Gb in size • Band 6 files are up to about 295 Mb in size • Band 8 data are huge, won’t fit in single files – Up to about 4.6 Gb of data in a 35-scene subinterval – HDF 4 limits file sizes to 2 Gb – Written to up to three separate swaths in separate segment files ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 10
  11. 11. The Band Files — Geolocation • Geolocation structures – Uses HDF-EOS Index map to link WRS scene corner lon/lat coordinates to the Swath • Full scenes from 30m-res. bands are always 6,000 data lines • Partial scenes at the beginnings and ends of subintervals are of irregular sizes – Uses Time Geolocation field to temporally locate scans in the Swaths • HDF-EOS Geolocation structures also used to store other ancillary data ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 11
  12. 12. The Internal Calibrator (IC) Files • Contain lamp and shutter data for spectral bands • Contain blackbody radiance and shutter data for thermal band (band 6) • One file for each format – Separate HDF-EOS Swath for each band • One data set per scan • Data located by Time only using HDF-EOS Geolocation structure ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 12
  13. 13. Mirror Scan Correction Data (MSCD) Files • Mainly contain data quality information • Stored in an HDF-EOS Point • Located by Time only using HDF-EOS Geolocation structure • Format 1 and Format 2 MCSD are identical except for start and end offsets at the beginnings and ends of the data ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 13
  14. 14. Other LPS Product Files • Payload Correction Data (PCD) Files – Contain spacecraft attitude and ephemeris information and miscellaneous engineering data – Native HDF Vdata, no HDF-EOS structures – Format 1 and Format 2 are identical • Metadata Files – Format 1 and Format 2 similar, but not identical – Simple text file in Object Definition Language (ODL) Syntax • Browse Files – – – – Format 1 only One native HDF RIS24 true color image Made from three of the five format 1 spectral bands JPEG Compressed images ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 14
  15. 15. LPS Browse File (Hudson Bay) ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 15
  16. 16. Format 1 • Six Band files – Bands 1-5 and 6L • • • • One Internal Calibrator (IC) data file One Payload Correction Data (PCD) file One Mirror Scan Correction Data (MSCD) file One Metadata file – Includes scene cloud cover assessments • 1 to 37 Multi-band Browse files ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 16
  17. 17. Format 2 • Three Bands, up to five files – Bands 6H and 7 – Band 8 (High-Resolution Panchromatic Band) • Written to up to three segment files due to size • • • • • One Internal Calibrator (IC) data file One Payload Correction Data (PCD) file One Mirror Scan Correction Data (MSCD) file One Metadata file No Browse files ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 17
  18. 18. The LPS Product File Set ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 18
  19. 19. Level Zero-R Data Subsets • Single WRS scene products – One 375 scan subset – Data fitted to the WRS grid • Multiple scene products – Contains several contiguous WRS scenes • Partial subinterval (a.k.a., floating scene) products – Similar to the multiple scene products, but not aligned along WRS rows • Full subinterval products – Essentially the full LPS subinterval ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 19
  20. 20. Subsetting the LPS Subintervals • LPS Band and IC files contain geolocated HDF-EOS Swaths – Can subset band data by index-mapped WRS scene corner geographic coordinates or time using HDF-EOS functions • Band 8 presents a problem due to file segmentation – Can subset IC data by time using HDF-EOS functions • MSCD file contains an HDF-EOS Point – Can subset by time using HDF-EOS functions • PCD is native HDF and cannot be subsetted using HDF-EOS functions ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 20
  21. 21. LPS Subsetting Difficulties • Band data Swaths are stored in separate files • Format 1/Format 2 data offset • Partial subinterval geolocation – LPS only computes lon/lat coordinates for WRS scene corners, not on a scan basis – Must interpolate subset interval corner coordinates • Band 8 segmentation – HDF-EOS does not support file segmentation ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 21
  22. 22. Band 8 Subsetting Problem • Must treat the band 8 segments as completely separate data sets • Subsetting out multiple scene or partial subinterval products from band 8 is especially complicated if the subset interval spans across segments • After subsetting from the two segments, the data must be concatenated into a single array ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 22
  23. 23. Level Zero-R Distribution Product • Native HDF, no HDF-EOS structures • Contains data from both Format 1 and Format 2 • Subsets of Band and IC data written to Scientific Data Sets (SDS) • Subset of MSCD written to Vdatas • Complete PCD and Metadatas written to Vdatas • Contains Calibration Parameter File (CPF) • Stores all data in HDF external elements ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 23
  24. 24. L0R Distribution Product File Set ESDIS HDF-EOS Workshop IV Landover, Maryland, September 20, 2000 24

×