Measuring and Monitoring Landsat 8 Data Quality - …. Department of the Interior U.S. Geological...
Transcript of Measuring and Monitoring Landsat 8 Data Quality - …. Department of the Interior U.S. Geological...
U.S. Department of the Interior
U.S. Geological Survey
March 27, 2014
Measuring and Monitoring Landsat 8
Data Quality
Ron Hayes SGT, contractor to the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center
Sioux Falls, South Dakota
*Work performed under U.S. Geological Survey contract G10PC00044
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Overview
Prelaunch Cal
On-orbit checkout
Operational calibration
Database Trending
Key Performance Requirements for OLI
Vicarious calibration
Lunar calibration
Pseudo Invariant Calibration Sites (PICS)
Quality Band
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OLI Pre-Launch Performance Characterization
Spatial/Geometric – SPAtial Test Set (SPATS)
Edge Response
Ghosting
Line-of-Sight
Spectral - CAlibration Test Set –SPectral (CATS-SP)
Relative Spectral Response
Radiometric – CATS - Radiometric Calibration (RC)
Responsivity/Absolute Calibration, Stability
Noise (SNR, coherent, etc)
Uniformity and Linearity
Polarization Sensitivity
Heliostat Test/Transfer to Orbit
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Geometric Commissioning Tasks
Launch to First Light 1: Analyze X-Band Test Data
2: Monitor ACS Calibration
First Light to WRS-2 3: First TIRS Earth Acquisition
4: First OLI Earth Acquisition
5: Initial OLI Alignment Cal
6: OLI-TIRS Co-Alignment Check
7: OLI Focus Check
8: TIRS Focus Check
9: Initial On-Orbit Calibration
10: TIRS SSM Update
11: Off-Nadir Data Analysis
12: Lunar Data Processing
13: Pre-WRS CPF Update
14: Jitter Characterization
15: OLI MTF (Spatial) Analysis
16: OLI Stellar Cal Analysis
WRS-2 Orbit 17: Run-for-Record CPF Update
18: Run-for-Record Characterization
19: OLI Requirements Verification
20: TIRS Requirements Verification
21: KPR Evaluation Baseline
22: Commissioning Report
Anomalies Some contingency activities included
(e.g., updating the TIRS SSM pointing target, phase 2 jitter testing) but other anomaly investigation activities were not covered by the plan
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Radiometric Commissioning Tasks
Launch to First Light 1: Analyze X-Band Test Data
First Light to WRS-2 2: Assess first TIRS Science Data
3: Assess First OLI Science Data
4: Process First TIRS Earth Image
5: Process First OLI Earth Image
6: OLI Txfr-to-Orbit:Initial Gain Update
7: OLI Initial Relative Gain Update
8: TIRS Initial Relative Gain Update
9: TIRS Calibration Stability Analysis
10: OLI Calibration Stability Analysis
11: OLI Relative Gain Evaluation
12: TIRS Relative Gain Evaluation
13: Lunar Data Processing
14: Pre-WRS On-Orbit CPF Update
15: L7 Cross Calibration with OLI
16: L7 Cross Calibration with TIRS
17: OLI Absolute Calibration Validation
18: TIRS Absolute Calibration Validation
WRS-2 Orbit 19: Run-For-Record CPF Update
20: Run-for-Record Radiometric Performance Characterization
21: OLI On-Orbit Req. Verification
22: TIRS On-Orbit Req. Verification
23: Establish OLI KPR Baseline
24: Commissioning Report
Anomalies Anomalies expected to be dealt with
under each task
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On-Board Calibration Mechanisms • A shutter wheel assembly sits between
the baffle and the aperture stop.
• Light enters the telescope during
nominal observations and the wheel will
rotate and act as a shutter.
• A second baffle, for solar views,
intersects the Earth-view baffle at a
90°angle and a three-position diffuser
wheel assembly dissects the angle.
• Two solar diffuser panel positions that
diffuse the optical path through the
Earth-view baffle.
• Working panel
• Pristine panel
• Two stimulation lamp assemblies hold
six small lamps illuminate the OLI focal
plane
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Landsat Operational Calibration
Automated work order generation via User Portal available for calibration scenes
Image Assessment System (IAS) used for majority of analysis
CVTK used for some analyses
Coherent noise, relative gain, non-linear response characterization, SNR/NEDL, and detector operability
CPF updates are performed quarterly to update UT1 and file attributes. And as needed for all other calibration trend updates.
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Approximately 550 scenes per day are collected by Landsat 8
Every Scene is trended through the Ingest system in operations and every product that is produced in the Landsat Product Generation System (LPGS) is trended.
Landsat Operational Calibration
Typical Day
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Landsat 8 Coverage Since Launch
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Landsat 8 Databases
The Ancillary Data database
CPF / BPF database
Geometric / Radiometric Characterization database
Per detector, Per SCA or Per Scene statistics trended
Histogram Stats trends per detector
Some char – (ie. Detector Saturation) Every pixel is checked, but the database only trend when condition met
Geometric Char: 20 data aspects are trended
Band Char, Band Cal, Focal Plan Char and Cal, Geodetic Char and cal, Image Char and Cal, MTF bridge info, Model Generation, Sensor Alignment, Precision model correction, and TIRS alignment
Radiometric characterizations 41 aspects are trended
Bias, Detector mapping, Gain, Histogram Stats, Impulse Noise, Lamp Response, Lunar characterization, NEDL, uniformity, Overlap stats, PICS, ROLO characteristics, Saturated pixels, SNR char, solar char, striping.
Hist Stats characterizes for every 95122 detectors in a scene that are characterized.
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Key Performance Requirements (KPR)
12 KPR’s that contractually define expectations for 60 months of the OLI contract between the USGS and BATC.
Includes a standard performance level, a positive incentive, and a negative incentive.
KPR# Description Positive
Incentive
Negative
Incentive
Measured Each
WRS-2 Cycle
Measured
Weekly
Measured
Monthly
Measured
Bi-monthly
1 Availability X X
2 Imaging Execution X X
3 Signal to Noise Ratio X X X
4 Edge Response Slope X
X
X
5 Image Swath Width X X
6 Coverage X
7 Band to Band Registration
Accuracy
X
X
12 scenes
per month
8 Radiometric Stability X
9 Banding X X
10 Streaking X X
11 Dead or Inoperable
Detectors
X
X
X
12 Out of Spec Detectors X
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Vicarious Calibration - OLI
South Dakota state University (SDSU)
University of Arizona (Uaz)
Absolute calibration of satellite sensor using
reflectance-based ground truth
measurement of a test site along with
concurrent atmospheric measurement and
a simultaneous satellite collect over the test
site.
The predicted at sensor values are then
compared with the values from the satellite
sensor to obtain the calibration coefficient
for each spectral band of the satellite
sensor.
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Vicarious Calibration – TIRS
Rochester Institute of Technology (RIT)
NASA Jet Propulsion Laboratory (JPL)
Buoy temps propagated through the atmosphere to approximate the apparent temperature seen by the satellite provides a reference for Thermal cal.
National Data Buoy Center
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Temperature Diff BuoyTruth – L8
Band 10 Temp Diff Ave: -2.197 St Dev: -0.891
Band 11 Temp Diff Ave: -3.208 St Dev: -1.156
-6
-5
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020
13-0
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13-0
5-0
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6-2
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13-0
8-1
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13-1
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Tem
pera
ture
Dif
fere
nce
Bu
oyT
ruth
- L
8
temp_b10_truth-L8
temp_b11_truth-L8
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Band 10 Radiance Diff Ave: -0.283 St Dev: -0.117
Band 11 Radiance Diff Ave: -0.398 St Dev: -0.145
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6.5
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7.5
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8.5
9
9.5
10
6 6.5 7 7.5 8 8.5 9 9.5 10
L8
ra
dia
nc
e
Truth: Buoy Derived Radiance
Band 10
Band 11
one to one
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Lunar Calibration
Edge slope investigations
Radiometric target + no atmosphere! Useful for Cirrus band
Stray light analysis
Working with ROLO
Lunar calibration interface is being developed to deliver reference lunar irradiances corresponding to L8 observations.
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Pseudo Invariant Calibration Sites PICS
South Dakota State University (SDSU) and the Landsat CVT created an empirical absolute calibration model using PICS to calibrate satellite data.
Using the most stable locations (pseudo invariant)
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Pseudo Invariant Calibration Sites PICS
Dry desert areas that are typically low clouds are ideal
Tasked to collect these scenes at every opportunity
The IAS trends each ROI in the database.
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Libya 1
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Mauritania 1(WRS Path /Row: 201/47)
0 1000 2000 3000 4000 50000.18
0.2
0.22
0.24
Temporal Trend of L7 ETM+ TOA reflectance (Blue)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 3.96%
Mauritania 1 ,148scenes
0 1000 2000 3000 4000 50000.26
0.28
0.3
0.32
0.34
0.36
Temporal Trend of L7 ETM+ TOA reflectance (Green)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 2.35%
Mauritania 1 ,148scenes
0 1000 2000 3000 4000 50000.35
0.4
0.45
0.5
Temporal Trend of L7 ETM+ TOA reflectance (Red)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 1.37%
Mauritania 1 ,148scenes
0 1000 2000 3000 4000 50000.45
0.5
0.55
0.6
0.65
Temporal Trend of L7 ETM+ TOA reflectance (VNIR)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 2.53%
Mauritania 1 ,148scenes
0 1000 2000 3000 4000 50000.55
0.6
0.65
0.7
0.75
Temporal Trend of L7 ETM+ TOA reflectance (SWIR 1)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 2.05%
Mauritania 1 ,148scenes
0 1000 2000 3000 4000 5000
0.5
0.6
0.7
Temporal Trend of L7 ETM+ TOA reflectance (SWIR-2)
Days Since 04/15/1999
TO
A r
efl
ec
tan
ce
Temporal uncertainty = 3.52%
Mauritania 1 ,148scenes
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0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
17-Mar-13 6-May-13 25-Jun-1314-Aug-13 3-Oct-13 22-Nov-1311-Jan-14 2-Mar-14 21-Apr-14
TO
A R
efl
ecta
nce
Time (year)
L8 OLI TOA Reflectance over Libya4
Band1
Band2
Band3
Band4
Band5
Band6
Band7
Landsat 8 trending database results
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Quality Band
The QA image is a 16-bit mask which marks clouds, fill data, and some land cover types.
The QB looks like any other band file and is a 16-bit image with the same dimensions as the L1T scene.
The bits are assigned to various processing artifacts that are identified in the L1 processing.
The detailed information in the QB is in binary form, and the pixels are decimal integers, and therefore the user must convert the decimal to binary in order to use the file. Section 2.1.2 of the LDCM L1 DFCB must be referenced in order to see what each bit represents.
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Quality Band
For single-bit flags such as Fill or Terrain Occlusion, a '1' in a pixel indicates the presence of the feature.
Two-bit flags such as clouds or cirrus form a confidence score that describes the probability of the feature being present.
Dec Hex Binary Cloud Cirrus Snow/Ice Veg CS Water
-
-
Terr
Occ.
Drop
Frame Fill
61440 F000 11110000 00000000 11 11 00 00 00 00 0 0 0 0
59424 E820 11101000 00100000 11 10 10 00 00 10 0 0 0 0
57344 E000 11100000 00000000 11 10 00 00 00 00 0 0 0 0
53248 D000 11010000 00000000 11 01 00 00 00 00 0 0 0 0
00 = Not set.
01 = Low confidence, 00-35%
10 = Mid confidence, 36-64%
11 = High confidence, 65-100%
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Quality Band
A pixel with a value "58384" translates to the 16-bit binary string "1110 0100 0001 0000." Using the table above as an interpretation legend, this pixel is:
http://landsat.usgs.gov/CDR_ECV.php
http://landsat.usgs.gov/L-LDOPE_Toolbelt.php The software is delivered in a zip file that contains the executables compiled for Linux 32-Bit
and 64-Bit, Windows 32-Bit and 64-Bit systems, accompanied by the source code and a readme file.
Bit 0 = 0 = not fill Bit 8 = 0 = not populated
Bit 9 = 0 = not populated Bit 1 = 0 = not a dropped frame
Bit 2 = 0 = not terrain occluded Bit 10 = 1 = snow/ice
Bit 11 = 0 = not snow/ice Bit 3 = 0 = not populated
Bit 4 = 0 = not water
Bit 5 = 0 = not water
Bit 12 = 0 = not a cirrus cloud
Bit 13 = 1 = cirrus cloud
Bit 6 = 0 = not populated
Bit 7 = 0 = not populated
Bit 14 = 1 = cloudy
Bit 15 = 1 = cloudy
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Quality Band
P152 R028 Browse P152 R028 QB Browse
Bit Description Color
0 Designated Fill
1 Dropped Frame 2 Terrain Occlusion 3 Water* 4 Vegetation* 5 Snow/Ice* 6 Cirrus* 7 Cloud*
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Quality Band
P047 R027 Browse P047 R027 QB Browse
Bit Description Color
0 Designated Fill
1 Dropped Frame 2 Terrain Occlusion 3 Water* 4 Vegetation* 5 Snow/Ice* 6 Cirrus* 7 Cloud*
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Quality Band
P031 R044 Browse P031 R044 QB Browse
Bit Description Color
0 Designated Fill
1 Dropped Frame 2 Terrain Occlusion 3 Water* 4 Vegetation* 5 Snow/Ice* 6 Cirrus* 7 Cloud*
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Questions?