TIR Radiometry : Validation of Thermal
Infrared Remotely Sensed Data In-Flight
using an Automated Validation Site –
Lake Tahoe CA/NV, USA
Simon J. Hook, Fred Prata, Geoff Schladow, Ali Abtahi, Ron Alley,
Bob Richards, Frank Palluconi, Brian Markhum, Julia Barsi,
Gyanesh Chander
(JPL, UCD, GSFC, EDC, SDSU)
Outline
• Introduction
• Location and in-situ measurements
• Laboratory calibration and field verification of insitu measurements
• Validation methodology
• Validation results
– Radiance at sensor
•
•
•
•
MODIS,
ASTER
Landsat 5
ETM+
• Conclusions/Future work
Introduction
• “The great strength of satellites, their overarching view of the planet, is
counterbalanced by their great weakness: They are far from the substances
(air, land, water) they are trying to measure. Scientifically, the best
combination is often to use the satellite and an in situ sensor (one that is in the
air or the ocean), with the satellite painting a broad and comprehensive
picture and the in situ sensors providing calibration and necessary detail.” (MacDonald, A. E., The Wild Card in the Climate Change Debate, Issues in
Science and Technology Online, 2001.)
• “Scenarios examined in this Assessment, which assume no major
interventions to reduce continued growth of world greenhouse gas
emissions,indicate that temperatures in the US will rise by about 5-9°F (35°C) on average in the next 100 years, which is more than the projected
global increase.” - National Assessment Synthesis Team, Climate Change
Impacts on the United States: The Potential Consequences of Climate
Variability and Change, 2001
Location
Location
Why Lake Tahoe?
•
•
•
•
•
•
•
Large 35 km x 16 km
High 2 km
Available year round (does not freeze in winter).
Homogenous compared with land.
Large annual temperature range 5-25 C.
Freshwater (kind to instruments!)
Good infrastructure and easy access.
2000-09-20-D
Bulk temperature measurements
Total Sky Imager (TSI)
and Shadowband
Radiometer above
Tahoe Gauging Station
at US Coast Guard.
Laboratory Calibration and Field
Verification of Insitu Measurements
• Bulk temperature
– Laboratory calibration
– Field verification
• Radiometric temperature
– Laboratory calibration
– Field verification
Laboratory Calibration: Radiometer
• NIST designed cone in a 44 liter temperature
controlled bath. Stability at 25 C: +/- 0.0007 C
(7008-IR)
• Thermistor standard probe with an accuracy
specification of 0.0015 ° C over 0-60 ° C and
stability/yr of 0.005 ° C. (Model 5643-R)
• Readout system with an accuracy of 0.0025 ° C at
25 ° C and resolution of 0.0001 ° (Chub E4)
• Secondary standard PRT.
Laboratory Calibration of Radiometer
Cross Comparison of Radiometers at Miami
Cross Comparison of Radiometers at Miami
Means and standard deviations of the estimated skin
SST differences between pairs of radiometers for the
entire cruise period, and for each half of the cruise
Time
Radiometer
Pair
MAE-ISA
MAE-SIS
MAE-JPL
MAE-DAR
ISA-SIS
ISA-JPL
ISA-DAR
SIS-JPL
SIS-DAR
JPL-DAR
150.50 to 152.00
Mean Std.Dev
N
(K)
(K)
0.002
0.135
80
0.046
0.066
144
0.007
0.114
148
-0.008
0.076
149
0.038
0.101
79
0.026
0.142
81
0.007
0.114
80
-0.048
0.099
144
-0.053
0.074
144
-0.014
0.103
148
150.50 to 151.25
Mean
Std.Dev
N
(K)
(K)
0.005
0.135
69
0.046
0.066
74
0.052
0.111
77
0.022
0.071
78
0.030
0.101
67
0.027
0.141
70
0.019
0.112
69
-0.009
0.103
74
-0.019
0.054
74
-0.028
0.102
77
151.25 to 152.00
Mean Std.Dev
N
(K)
(K)
–0.015
0.135
11
0.045
0.068
70
-0.042
0.096
71
-0.041
0.067
71
0.085
0.093
12
0.018
0.150
11
-0.064
0.107
11
-0.088
0.078
70
-0.088
0.076
70
0.000
0.102
71
Data Reduction: Methodology For
Radiance at Sensor Validation
• Extract the bulk temperatures.
• Extract the radiometric temperature.
• Correct the radiometric temperature to skin kinetic
temperature.
• Propagate the skin temperature to the satellite using a radiative
transfer model and interpolated atmospheric profile.
• Convolve the propagated at-sensor radiance to the instrument
response function to obtain the Vicarious Radiance (VR).
• Extract the image radiance derived using the On Board
calibrator (OBC).
• Compare and contrast the OBC and VR Radiance values.
Sensitivity Analysis for Correction of
Radiometric Temperature to Skin Temperature
Perturbation
None
Blackbody Target
No Sky Radiance
Water Factor 0.7
Water Factor 1.3
Air Temperature – 2.0 C
Air Temperature +2.0 C
Ozone Factor 0.5
Ozone Factor 1.5
Kinetic Temperature Difference from no
(degrees C)
perturbation
5.579
4.804
5.779
5.596
5.561
5.590
5.568
5.585
5.574
20.703
19.850
20.871
20.715
20.691
20.712
20.694
20.709
20.700
0.000
-0.775
0.200
0.017
-0.018
0.011
-0.011
0.006
-0.005
0.000
-0.853
0.168
0.012
-0.012
0.009
-0.009
0.006
-0.003
Results
MODIS Terra Vicarious and OBC Derived Radiances at Lake Tahoe
CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0
Vicarious Radiance (W/m2 µm sr)
8.0
7.0
6.0
1x1
03/12/2000
04/29/2000
04/30/2000
06/01/2000
06/17/2000
06/24/2000
07/02/2000
07/03/2000
07/18/2000
07/19/2000
08/04/2000
08/19/2000
08/20/2000
09/05/2000
09/20/2000
09/21/2000
10/06/2000
10/07/2000
10/22/2000
11/07/2000
02/27/2001
02/28/2001
03/16/2001
3/31/2001
4/1/2001
5/3/2001
5/18/2001
5/19/2001
6/3/2001
7/21/2001
7/22/2001
8/7/2001
8/22/2001
9/7/2001
9/8/2001
10/9/2001
10/19/2001
10/25/2001
10/26/2001
12/12/2001
1/14/2002
2/6/2002
3/2/2002
3/3/2002
3/18/2002
4/3/2002
4/4/2002
5/5/2002
5/6/2002
6/6/2002
6/7/2002
7/22/2002
7/8/2002
7/9/2002
7/25/2002
8/9/2002
8/25/2002
8/26/2002
9/2/2002
9/10/2002
9/11/2002
9/26/2002
10/12/2002
10/13/2002
10/29/2002
11/29/2002
1/16/2003
5/24/2003
6/9/2003
6/10/2003
6/25/2003
6/26/2003
7/11/2003
7/12/2003
7/28/2003
8/12/2003
8/28/2003
8/29/2003
9/13/2003
9/14/2003
5.0
4.0
3.0
2.0
2.0
3.0
4.0
5.0
6.0
OBC Radiance (W/m2 µm sr)
7.0
8.0
MODIS Terra Vicarious and OBC Derived Radiances at Lake Tahoe
CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0
Vicarious Radiance (W/m2 µm sr)
8.0
7.0
6.0
1x1 line
5.0
Band 28 (7.34 um)
Band 29 (8.53 um)
4.0
Band 30 (9.73 um)
Band 31 (11.01 um)
3.0
Band 32 (12.03 um)
Band 33 (13.37 um)
2.0
2.0
3.0
4.0
5.0
6.0
OBC Radiance (W/m2 µm sr)
7.0
8.0
MODIS Terra Vicarious and OBC Radiances at Lake Tahoe
CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0
8.50
1x1 line
Vicarious Radiance (W/m2/sr/µm)
Band 29 (8.53 um)
8.00
Band 31 (11.01 um)
Band 32 (12.03 um)
7.50
7.00
Linear (Band 29 (8.53
um))
Linear (Band 31 (11.01
um))
Linear (Band 32 (12.03
um))
Linear (Band 29 (8.53
um))
Band 29
Band 31
Band 32
6.50
y = 0.9801x + 0.1392
R2 = 0.9945
y = 0.9674x + 0.2422
R2 = 0.9946
y = 0.9587x + 0.3012
R2 = 0.9938
6.00
5.50
5.50
6.00
6.50
7.00
7.50
OBC Radiance (W/m2/sr/µm)
8.00
8.50
(3
-0.5
3
/1
2
(4 D)
/3
5 0N
(6 )
/
7 17N
(7 )
/
9 02D
(7 )
11 /18
(8 D
13 /04 )
(8 N
15 /20 )
N
17 (9/2 )
0
(1 D
19 0/0 )
(1 6D
21 0/2 )
(0 2N
23 2/2 )
(0 7D
25 3/1 )
(0 6N
27 4/0 )
(0 1N
29 5/1 )
(0 8D
31 6/0 )
(0 3D
33 7/2 )
(0 2N
35 8/2 )
(0 2D
37 9/0 )
(1 8N
39 0/1 )
(1 9N
0 )
41 /26
(1 N)
/
43 14N
(
45 3/2 )
(3 D)
/
47 18D
(4 )
49 /4N
(5 )
51 /6N
53 (6/7 )
(7 N
55 /08 )
(7 D
57 /25 )
(8 N
59 /25 )
(9 D
61 /02 )
N
63 (9/1 )
(1 1N
65 0/1 )
(1 2D
0/ )
29
N
)
1
Vicarious - OBC BT's (C)
MODIS Terra Temperature Difference between Vicarious and OBC Derived BT's
at Lake Tahoe CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0
2.0
1.5
-2.0
Band 29 (8.53 µm)
Band 31 (11.01 µm)
-1.0
-1.5
Overpass Date
Band 32 (12.03 µm)
1.0
0.5
0.0
/1
(3
-0.5
4
2
(6 D)
/0
7 1N
(7 )
10 /02
(7 D)
13 /19
(8 N)
16 /20
( N
19 9/2 )
(1 1N
22 0/2 )
(0 2N
25 2/2 )
(0 8N
28 4/0 )
(0 1N
31 5/1 )
(0 9N
34 7/2 )
(0 2N
37 9/0 )
(1 7D
40 0/1 )
(1 9N
2/ )
1
43 2D
(3 )
46 /2D
(4 )
49 /3D
( )
52 5/6
(6 N)
55 /22
(7 D)
58 /25
(8 N)
61 /26
( N
64 9/1 )
(1 1N
0 )
67 /13
(1 N)
70 /16
(6 D)
73 /10
(7 N)
76 /11
(8 /D)
79 /12
(9 /D)
/1
3/
D
)
1
Vicarious - OBC BT's (C)
MODIS Terra Temperature Difference between Vicarious and OBC Derived BT's
at Lake Tahoe CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0
2.0
Side A - launch to October 31 2000
1.5
Side B November 1 2000 to June 15 2001
1.0
0.5
0.0
-1.0
-1.5
Band 31 (11.01 µm)
-2.0
Overpass Date
MODIS Temperature Difference between Vicarious and OBC Derived BT's at Lake Tahoe
CY2000-2003 v2.5.4, v2.5.5, v3.0.0, v3.0.1, 4.0.9, 4.1.2, 4.2.0- Night Only
2.0
Side A - launch to October 31 2000
Vicarious - OBC BT's (C)
1.5
Side B November 1 2000 to June 15 2001
1.0
0.5
0.0
)
N
0
3
/
-0.5
(4
3
5
)
N
7
1
/
(6
8
)
N
3
0
/
(7
11
/
(8
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
N
N
N
N
N
N
N
N
N
N
N
N
/N
4
9
6
1
6
3
6
1
9
7
9
9
/
/
9
0
1
0
1
2
/
/1
/0
/2
/1
/2
/2
(3
(5
0/
2/
4/
5/
8/
0/
0/
(9
(1
(7
(8
(9
(6
1
0
0
0
0
1
1
(8
4
9
(
(
(
(
(
(
(
4
1
4
8
1
2
4
4
1
4
5
5
6
7
78
18
22
25
28
32
37
65
)
N
4
0
)
N
5
0
N
07
N
28
-1.0
-1.5
Band 31 (11.01 µm)
-2.0
Overpass Date
ASTER
ASTER 3x3 pixel Vicarious and On Board Calibrator (OBC) Derived Radiances at
Lake Tahoe CY2000-2003 versions 1.02, 2.05, 2.06, 2.09, 2.13, 2.14
8.50
Vicarious Radiance (W/m2 sr µm)
1x1 line
8.00
7.50
7.00
6.50
6.00
5.50
5.50
Band 10 (8.29 um)
Band 11 (8.63 um)
Band 12 (9.08 um)
Band 13 (10.66 um)
Band 14 (11.29 um)
Linear (Band 10 (8.29
um))
Linear (Band 11 (8.63
um))
Linear (Band 12 (9.08
um))
Linear (Band 13 (10.66
Band 10
um))
Linear (Band 14 (11.29
y = 1.0013x + 0.018
um))
2
R = 0.9962
Linear (Band 11 (8.63
um))
6.00
y = 0.9988x + 0.038
R2 = 0.9959
6.50
Band 13
Band 12
Band 11
y = 0.9957x + 0.0393
R2 = 0.9965
y = 0.9965x + 0.0568
2
R = 0.9923
7.00
7.50
OBC Radiance (W/m2 sr µm)
Band 14
y = 0.9899x + 0.0982
R2 = 0.9949
8.00
8.50
3/
1
(0 2/0
0D
6
3 /24 )
(0 /0
0N
8
4 /04 )
(0 /0
0N
8
5 /19 )
(0 /0
0D
8
6 /20 )
(1 /0
0N
1
7 /07 )
(0 /0
0D
2
8 /27 )
/
(0
01
2
D
9 /28 )
(0 /0
1
10 3/1 N)
6
(0 /0
1
11 6/0 N)
3
/
(0
01
12 7/2 D)
(0 2/0
1
13 8/2 N)
2
(1 /0
1
14 0/0 D)
9
/
(1
01
15 1/0 D)
(0 3/0
1
16 1/1 D)
4
(0 /0
2
17 2/0 N)
6
/
(0
02
18 6/0 N)
(0 6/0
2
19 6/0 D)
7
(0 /0
2
20 6/2 N)
2
(0 /0
2
21 9/0 D)
2
(0 /0
2
22 9/1 D)
0
(0 /0
2
23 9/2 D)
6
(1 /0
2
24 0/1 D)
2
(1 /0
2
25 1/0 D)
4
(1 /0
2
26 1/2 D)
9
(1 /0
2
27 1/3 D)
0
(0 /0
2
28 7/1 N)
1
/
(0
03
29 7/1 D)
(0 2/0
3
30 8/1 N)
2
(0 /0
8/ 3D
29 )
/0
3D
)
%1 (Radiance
Difference
0
-1.0
2
ASTER 3x3 pixel % Radiance Difference between Vicarious and OBC Derived Radiances
v1.02 (1-8), v2.05 (9-10), v1.02 (11-13), v2.0.6 (14-22), v2.09 (23-26), v2.13(27-29), v2.14(30)
( ((V-O)/V)*100
3.0
2.0
1.0
0.0
-2.0
Band 10 (8.29 um)
Band 11 (8.63 um)
Band 13 (10.66 um)
Band 14 (11.29 um)
-3.0
Overpass Date
Band 12 (9.08 um)
3/
12
(0 /00
6/
D
3 24/ )
(0
0
8/ 0N
4 04/ )
(0
0
8/ 0N
1
5
9 )
(0 /00
8/
D
6 20/ )
(1
0
1/ 0N
7 07/ )
(0
0
2/ 0D
2
8
7 )
(0 /01
2/
D
9 28/ )
(0
01
3
10 /16 N)
( 0 / 01
6
11 /03 N)
(0 /01
7
12 /22 D)
(0 /01
8
13 /22 N)
(1 /01
0
14 /09 D)
(1 /01
1
15 /03 D)
(0 /01
1
16 /14 D)
(0 /02
2
17 /06 N)
(0 /02
6
18 /06 N)
(0 /02
6
19 /07 D)
(0 /02
6
20 /22 N)
(0 /02
9
21 /02 D)
(0 /02
9
22 /10 D)
(0 /02
9
23 /26 D)
(1 /02
0
24 /12 D)
(1 /02
1
25 /04 D)
(1 /02
1
26 /29 D)
(1 /02
1
27 /30 D)
(0 /02
7
28 /11 N)
(0 /03
7
29 /12 D)
(0 /03
8
30 /12 N)
(0 /03
8/
29 D )
/0
3D
)
%1 (Radiance
Difference
0
-1.0
2
ASTER 3x3 pixel % Radiance Difference between Vicarious and OBC Derived Radiances
v1.02 (1-8), v2.05 (9-10), v1.02 (11-13), v2.0.6 (14-22), v2.09 (23-26), v2.13(27-29), v2.14(30)
( ((V-O)/V)*100
3.0
2.0
1.0
0.0
-2.0
Band 13 (10.66 um)
-3.0
Overpass Date
On Board Calibration of TIR
• Short term calibration performed for every
strip with blackbody set to nominal value.
• Long term calibration performed by
periodically looking at blackbody a 4
temperatures between 270 K and 340 K.
Temperatures are: 270 K, 300 K, 320 K and
340 K. To date ~ 50 long term calibrations
have been performed.
Radiometric Database Status
Radiometric Database
Date of On-board
Calibration
Ver. 1.0x, 2.00, 2.01, 2.02
85
Ver. 2.03, 2.04
270
Ver. 2.05
406
Ver. 2.06
607
Ver. 2.07
Ver. 2.08
Ver. 2.09
738
837
871
C1 of online RCC DB
9.00 10
8.50 10
Band 12
-3
-3
C1
v2.09
8.00 10
-3
v2.06
v2.05
7.50 10
-3
v1.0x
7.00 10
-3
0
200
400
600
Days
800
1000
1200
Calibration error in using online
RCC DB
Band 12 @ 300K
0.5
v1.0x
Calibration Error (K)
0
v2.05
-0.5
v2.06
-1
-1.5
-2
0
200
400
600
Days
800
1000
1200
Landsat 5
3.50
Landsat 5, Channel 6 Percent Delta Radiance between Vicarious and On Board Calibrator
(OBC) Radiances at Lake Tahoe CA/NV 1999-2002
% Delta Radiance ((V-O)/V) * 100
Percent Delta Radiance
3.00
2.50
2.00
1.50
1.00
0.50
0.00
-0.50
1999- 1999- 1999- 1999- 2000- 2000- 2000- 2000- 2000- 2000- 2001- 2001- 2001- 2001- 2001- 2001- 2001- 2001- 2001- 200207-08 07-24 10-12 11-13 06-24 07-26 08-11 08-27 09-28 12-17 03-07 04-24 05-10 05-26 06-11 07-13 08-11 09-15 10-01 02-06
-1.00
Date
ETM+ Band 6 Comparison: In Situ Derived Versus
Image Derived Top Of The Atmosphere Radiance
In Situ Derived TOA Radiance (W/m2/sr/µm) x100
1250
1150
1050
950
1a,b Lake Tahoe CA 02 September 1999
02 Cold Springs Reservoir NE 29 September 1999
03 Railroad Valley Playa NE 29 September 1999
04 Lake Tahoe CA 05 November 1999
5a,b Lake Tahoe CA 12 March 2000
06 Salton Sea CA 04 June 2000
07 Cold Springs Reservoir NE 14 August 2000
08 L ake Tahoe CA 07 November 2000
09 Lake Tahoe 27 February 2001
10 Lake Tahoe 22 August 2001
11 Salton Sea 17 January 2002
12 Lake Tahoe 02 March 2002
13 Lake Tahoe 06 June 2002
14 RRV Playa 17 June 2002
15 CS Reservoir 17 June 2002
16 Lake Tahoe 25 August 2002
17 Salton Sea 03 December 2002
18 Lake Tahoe 24 May 2003
10
7
15
850
10
16
1b
17
11
750
18
13
14
3
6
Green line is one-to-one.
Points 9 to 18 from images with Band 6
calibration bias correction in place.
Linear Fit
y = -30.13 + 1.0015*x R = 0.9996
1a
2
4
8
9
650
650
12
5a
5b
750
850
950
1050
Image Derived TOA (W/m2/sr/µm) x100
1150
1250
Summary Table of Validation of
Radiance at Sensor Product
Sensor
Band and
Center
(µm)
MODIS-T 29 (8.53)
MODIS-T 31 (11.02)
MODIS-T 32 (12.03)
Preflight
Number of
Calibration Dates
Accuracy
Validated
Req. 1
< 0.5%
< 0.5%
80
< 0.5%
MODIS-A 29 (8.56)
MODIS-A 31 (11.03)
MODIS-A 32 (12.04)
< 0.5%
< 0.5%
< 0.5%
ASTER
ASTER
ASTER
ASTER
ASTER
10 (8.29)
11 (8.63)
12 (9.08)
13 (10.66)
14 (11.29)
Landsat 5
6 (11.46)
Average of % Std Dev of %
Radiance
Radiance
Difference (%) Difference (%)
(BIAS)
Average of
BT
Difference
(K) (BIAS)
Std. Dev of BT
Difference (K)
0.02
-0.09
0.04
0.71
0.59
0.61
0.01
-0.06
0.03
0.33
0.36
0.40
7
-0.26
-0.07
0.13
0.79
0.67
0.64
-0.13
-0.04
0.09
0.38
0.42
0.44
≤ 1K
≤ 1K
≤ 1K
≤ 1K
≤ 1K
30
0.40
0.43
0.43
0.08
0.30
0.58
0.59
0.77
0.46
0.53
0.18
0.21
0.22
0.05
0.19
0.27
0.29
0.40
0.28
0.34
≤ 1K
19
1.81
0.66
1.16
0.43
Summary of Differences between Vicarious and OBC Derived BT's at Lake
Tahoe CY2000-2003 for MODIS-Terra, MODIS-Aqua, ASTER, Landsat 5
2.00
1.50
MODIS-Terra (80 matchup days)
ASTER (30 matchup days)
MODIS-Aqua (7 matchup days)
Landsat 5 (19 matchup days)
Bias
1.00
0.50
0.00
-0.50
8.00
9.00
10.00
11.00
Wavelength (µm)
12.00
13.00
Conclusions and Future Work
• Radiance at sensor measured by MODIS Terra and Aqua (channels
29,31,32) validated since launch. Analysis indicates calibration of these
channels meets preflight specification and has remained stable over duration
of mission.
• Radiance at sensor measured by ASTER channels (10-14) validated since
launch. Analysis indicates calibration is changing with time and is manifest
in product if radiometric coefficients are not implemented with sufficient
frequency. ASTER team has developed website where correction can be
downloaded for 1B, correction will be incorporated in higher level data
products in next delivery.
• Surface temperature derived by MODIS LST algorithm validated since
launch. Analysis indicates a small positive bias (0.2 K) bias is within
product specification (1K).
• Surface temperature derived by ASTER LST algorithm validated since
launch. Analysis indicates a negative bias (0.5 K) bias is within product
specification (1K). Bias varies with calibration drift.
• All products have potential to be Climate Data Records (CDR’s) as
compared to Environmental Data Records (EDR’s) because products have
been validated over lifetime of mission.
• Other sensors now being compared at Tahoe validation site. Sensor
comparisons will continue given sufficient resources.
Backups
Validation Results Higher Level
Products
• AST08 – Surface temperature
• AST05 – Surface emissivity
• MOD11 – Land surface temperature
03
/
06 1/2
/2 00
08 4/2 0
/0 00
08 4/2 0
/1 00
08 9/2 0
/2 00
11 0/2 0
/0 00
02 7/2 0
/2 00
02 7/2 0
/2 00
03 8/2 1
/1 00
06 6/2 1
/0 00
07 3/2 1
/2 00
08 2/2 1
/2 00
10 2/2 1
/0 00
11 9/2 1
/0 00
01 3/2 1
/1 00
02 4/2 2
/0 00
06 6/2 2
/0 00
06 6/2 2
/0 00
06 7/2 2
/2 00
09 2/2 2
/0 00
09 2/2 2
/1 00
09 0/2 2
/2 00
10 6/2 2
/1 00
11 2/2 2
/0 00
11 4/2 2
/2 00
11 9/2 2
/3 00
07 0/2 2
/1 00
07 1/2 2
/1 00
08 2/2 3
/1 00
2
08 /20 3
/2 03
9/ '
20
03
Delta T
Difference between ASTER LST (AST08) and Vicarious Skin Temperature at Lake
Tahoe CA/NV CY 2000-2003
2.00
1.50
1.00
0.50
0.00
-0.50
-1.00
-1.50
AST08 - Vicarious skin temp.
-2.00
Overpass Date
03
/
06 1/2
/2 00
08 4/2 0
/0 00
08 4/2 0
/1 00
08 9/2 0
/2 00
11 0/2 0
/0 00
02 7/2 0
/2 00
02 7/2 0
/2 00
03 8/2 1
/1 00
06 6/2 1
/0 00
07 3/2 1
/2 00
08 2/2 1
/2 00
10 2/2 1
/0 00
11 9/2 1
/0 00
01 3/2 1
/1 00
02 4/2 2
/0 00
06 6/2 2
/0 00
06 6/2 2
/0 00
06 7/2 2
/2 00
09 2/2 2
/0 00
09 2/2 2
/1 00
09 0/2 2
/2 00
10 6/2 2
/1 00
11 2/2 2
/0 00
11 4/2 2
/2 00
11 9/2 2
/3 00
07 0/2 2
/1 00
07 1/2 2
/1 00
08 2/2 3
/1 00
2
08 /20 3
/2 03
9/ '
20
03
Delta T
Difference between ASTER Products (AST1B and AST08) and Vicarious
Measurements at Lake Tahoe CA/NV CY 2000-2003
2.00
1.50
Delta skin temperature (AST08 - Vicarious)
Delta at sensor brightness temp. (Vicarious - Band 13)
1.00
0.50
0.00
-0.50
-1.00
-1.50
-2.00
Overpass Date
-0.50
-1.50
00
0
Delta T
7/
20
00
2/
2
7/ 000
19
/2
8/ 000
20
/2
9/ 000
21
/
10 200
/2
0
2/
20
3/
0
31 0
/2
5/ 001
19
/2
7/ 001
22
/2
0
9/ 01
7/
10 200
/1
1
9/
2
12
0
/1 01
2/
20
3/ 01
2/
20
4/ 02
3/
20
5/ 02
6/
20
7/ 02
8/
20
8/ 02
9/
2
9/ 002
10
/
10 200
/1
2
3/
2
01
0
/0 02
1/
05 200
/2
3
4/
2
06
0
/2 03
5/
07 200
/1
3
2/
2
08
0
/1 03
2/
09 200
/1
3
3/
20
03
1/
6/
/2
12
3/
Difference between MODIS LST (MOD011) and Vicarious Skin Temperature at Lake Tahoe
CA/NV CA/NV CY 2000-2003 v2.4.1, v3.0.1, v3.1.4, v4.0.4, v4.1.7, v4.1.11
2.00
1.50
1.00
0.50
0.00
-1.00
MOD011 - Vicarious skin temp.
-2.00
Overpass Date
Summary Table of Validation of
Surface Temperature Product
Product
Number
of dates
validated
MODIS-T (MOD11)
AATSR
ASTER (AST08)
For cover type: water
80
29
30
Average
Temperature
Difference
0.19
0.17
-0.50
Standard deviation
of temperature
difference
0.35
0.38
0.38
Uncertainty of
retrieved
temperatures
0.40
0.41
0.63
Skin Effect
Skin cooling
Temperature
0.1 mm
Sea
surface
Water
surface
Diurnal thermocline
2m
Depth
Night time
Afternoon
After Minnett et al. 2000
Variations in the bulk-, skin-, air-temperatures
and wind speed on June 7, 2001 at L. Tahoe
Detail from Calibration Run
TIR Subsystem
TIR Subsystem Characteristics
Scan
Telescope optics
Spectrum
separation
Focal plane
(Detector)
Cryocooler
Whiskbroom
Reflective (Newtonian)
Bandpass filter
HgCdTe (PC) 10x5
Stirling cycle, 80K
Scan mirror rotation +/Cross track pointing 8.55 degrees
Thermal control
Cold plate
Calibration
Blackbody 270-340 K
TIR Baseline Performance
Requirements
Band No
10-14
Maximum Input
Radiance
Radiance of a 370
K Blackbody
High Level Input
Radiance
Radiance of a
300 K blackbody
Low Level Input
Radiance
Radiance of a 200 K
blackbody
Laboratory Calibration: Bulk sensors
• Deep, mid-range (-10° C to 110 ° C), water bath
with a stability specification: ± 0.0008 ° C from
0-25 ° C. (Model 7012)
• Thermistor standard probe with an accuracy
specification of 0.0015 ° C over 0-60 ° C and
stability/yr of 0.005 ° C. (Model 5643-R)
• Readout system with an accuracy of 0.0025 ° C
at 25 ° C and resolution of 0.0001 ° (Chub E4)
• Secondary standard PRT.
Laboratory Calibration of bulk temperature sensors
Water Bath Calibration Run
Field Cross comparison of bulk sensors
Field Cross Comparison