1. Landsat Analysis Ready Data for LCMAP
Gene Fosnight
LSI-VC-3
Frascati, Italy
March 20, 2017

2. ARD Science Data and QA Bands
Collection Management
ARD processing flow
ARD Tiling
Top of Atmosphere Reflectance, Brightness Temperature, Surface Reflectance Measurements – primarily L8 examples
Per pixel metadata

3. Landsat Collection Management
Landsat data archive will, going forward, be managed as a formal tiered data Collection.
Managing the Landsat Archive as a Data Collection provides
a consistent archive of known data quality to support time series analyses and data “stacking”, while
controlling continuous improvement of the archive and
providing access to all data as they are acquired.
No change will be made to a Collection that would create a discontinuity in the environmental record.
Any significant change would be deferred to the release of a new Collection.

4. Collection Categories: aka Tiers
A Collection consists of three data categories: Tier 1, Tier 2, and Real-time.
Data in Tier 1 meet formal geometric and radiometric quality criteria.
Current criterion is a RMSE geometric threshold, but this not expected to always be the case
Data in Tier 2 do not meet the Tier 1 criteria.
The Real-time category contains data immediately after acquisition processed using estimated parameters.
Real-time data are reprocessed and assessed for inclusion into Tier 1 or Tier 2 as soon as final parameters are available.

5. Tiers
Tier 1 provides a starting point for data considered to be “optimal” for time series analysis
However it is understood that this is only a guideline and that application requirements and reality may intervene
For data rich areas and sensitive analysis, data with higher RMSE estimates can be rejected
For data poor and robust methodologies, data with lower RMSE estimates can be incorporated from Tier 2, which may require further georegistration
The goal of ARD is to provide sufficient metadata to permit adaptive selection of data from a ”data cube” structure.

6. Archive Characterization
Sensor
OLI/TIRS
ETM+ TM
Product %
%L1T
L1TP=<12m (T1)
62.60
90.66
74.98
96.51
64.78
96.23
L1TP>12m (T2)
6.45
2.71
2.68
L1GT/L1GS FB (T2)
14.78
17.70
28.39
L1GT/L1GS (T2)
16.17
4.61
4.15

7. OLI L1 Tier 1 L1TP Spatial Distribution
Green indicates greatest temporal density

8. ETM+ L1 Tier 1 L1TP Spatial Distribution
Green indicates greatest temporal density

9. TM L1 Tier 1 L1TP Spatial Distribution
Green indicates greatest temporal density

10. ARD Processing Flow

11. ARD Tiling Concept

12. Map Projection Parameters and Grid Extents

13. CONUS ARD Grid – after WELD

14. Alaska ARD Grid – after WELD

15. Landsat 8 TOA Reflectance Bands
Ta (top of atmosphere reflectance)
INT16 (16-bit signed integer)
Refl (reflectance)

16. Solar and Sensor View Angles
Sensor viewing angles
Sun angles
Azimuth
Zenith

17. Landsat 8 Brightness Temperature
bt (brightness temperature)
INT16 (16-bit signed integer)
K (Kelvin)
temp (temperature)

18. Landsat 4-7 Surface Reflectance
LEDAPS Version 3.0.0
Per pixel solar zenith angles corrections computed and applied
Quality Assurance bands remain as is; SR internal quality accompanies the product, CFmask-derived quality band is requested separately
Planned release into ESPA January 11, 2017 (this week)
LEDAPS Version 3.1.0
Revisions to QA band pixel quality attributes to support ARD generation (see next slide)
To be released no earlier than February 2017

19. Landsat 8 Surface Reflectance (LaSRC) Updates
LaSRC Version 1.0
Modifications to how aerosol retrieval is handled over water
Angstrom coefficient used to modify the AOT value
Per pixel solar azimuth and zenith angles computed and applied
Aerosol inversion algorithm applied to all pixels including clouds
Aerosol retrieval algorithm spatially interpolates ancillary data for each pixel
Cloud and ipflag Quality Attributes bands are now combined into one aerosol Quality Attributes band
Addition of new Pixel Quality Attributes (pixel_qa) and Radiometric Saturation Quality Attributes (radsat_qa) bands

20. Landsat 8 Surface Reflectance
sr (surface reflectance)
INT16 (16-bit signed integer)
Refl (reflectance)

21. Spectral Band Differences

22. ARD Quality Band Specifications
QA quality assurance, UINT16 16-bit unsigned integer, INT16 16-bit signed integer, NA not applicable, UINT8 8-bit unsigned integer, SR surface reflectance, toa top of atmosphere reflectance, NA not applicable

23. Quality Band Bit Value Cumulative Sum Description - OLI 11
Designated Fill 2 3
Terrain Occlusion 4 7
Radiometric Saturation 8 15 16 31
Cloud 5
x32 63
Cloud Confidence 6 64
127
128
255
Cloud Shadow
256
511 9
512
1023
Snow/Ice 10
1024
2047 11
2048
4095
Cirrus 12
4096
8191 13
8192
16383 14
16384
32767
32786
65553
Bit
Value
Cumulative Sum
Description – TM/ETM+ 1
Designated Fill 2 3
Dropped Pixel 4 7
Radiometric Saturation 8 15 16 31
Cloud 5 32 63
Cloud Confidence 6 64
127
128
255
Cloud Shadow
256
511 9
512
1023
Snow/Ice 10
1024
2047 11
2048
4095 12
4096
8191 13
8192
16383 14
16384
32767
32786
65553

24. Landsat 4-7 Radiometric Saturation Quality Bit Index
LSB least significant bit, MSB most significant bit, PQA pixel quality attributes

25. Landsat 8 ARD Lineage Quality Attribute Band

26. Tile Lineage QA Band

27. Landsat 8 ARD Internal Surface Reflectance Aerosol Quality Bits

28. Landsat 8 ARD Internal Surface Reflectance Aerosol Quality Bit Values

29. Landsat ARD Tile-based XML Metadata
Global Metadata
Level-2 Pixel QA Metadata
Level-2 Radiometric Saturation QA Metadata
Level-2 Lineage QA Metadata
Level-2 Angle Band Metadata
Level-2 TOA Reflectance Metadata
Level-2 Brightness Temperature Metadata
Level-2 Surface Reflectance Metadata
Level-1 Scene Metadata

30. Analysis Ready Data (ARD) for the U.S.
Finalizing Data Format Control Book (DFCB) that lays out product specifications, format, and packing details
Generation of and public access to sample ARD products conforming to DFCB no earlier than March 2017
Begin CONUS ARD in late February and public access no earlier than May 2017
Currently working on integrating and refining LaSRC for ESPA
Begin processing OLI/TIRS CONUS ARD is still TBD
Tiling is a separate processing step that follows Level-2 processing
Initial investigations into Global ARD tiling based on the OGC Discrete Global Grid System have begun.