3 SMOS and Aquarius/SAC-D Missions
53
observation consisting of a 5.76s data integration along track for each of the 3
Aquarius radiometer beams. The allocation is given in Table 3.2, where the sources
are combined as a root sum square. Both the allocation and the current best estimate
(CBE) are shown, and the margin is defined as the additional rss error that could
Table 3.2 Top portion shows the allocated sensor and geophysical errors (left column) in terms
of v-polarized brightness temperature (T BV ) in Kelvin (K), and the Current Best Estimate (CBE)
(right column) for each measurement with 5.76s integration time. The radiometer CBE data are
based on the Aquarius instrument pre-launch calibration data. The margin is the additional RSS
error that could be included before exceeding the allocation. Bottom portion shows the monthly
RMS salinity error by latitude band based on the total error allocation of 0.38 K per sample. These
include the measurement sensitivity as it varies with SST and the number of samples averaged
per latitude band. The global RMS error allocation over all the latitude bands is 0.2 and CBE
0.15 (pss)
3 beam RMS (K)
Error sources
Allocation
CBE
Radiometer
0.15
0.13
Antenna
0.08
0.01
System pointing
0.05
0.02
Roughness
0.28
0.13
Solar
0.05
0.02
Galactic
0.05
0.04
Rain (Total liquid water)
0.02
0.01
Ionosphere
0.06
0.05
Atmosphere – other
0.05
0.02
SST
0.10
0.07
Antenna gain near land & ice
0.10
0.10
Model function
0.08
0.07
Brightness temperature error per observation
Baseline mission 3 beams RMS (K)
Allocation
CBE
Total RSS (K)
0.38
0.24
Margin RSS (K)
0.30
Baseline mission monthly salinity
error (psu)
Latitude range
Mean sensitivity
(dTv/dS)
Mean # samples
in 28 days
Allocation
CBE
0–10
0.756
10.9
0.15
0.10
11–20
0.731
11.3
0.16
0.10
21–30
0.671
12.1
0.16
0.10
31–40
0.567
13.5
0.18
0.12
41–50
0.455
15.9
0.21
0.13
51–60
0.357
20.3
0.24
0.15
61–70
0.271
30.2
0.26
0.16
Global RMS (pss)
0.20
0.13
Margin RSS (pss)
0.15
53
observation consisting of a 5.76s data integration along track for each of the 3
Aquarius radiometer beams. The allocation is given in Table 3.2, where the sources
are combined as a root sum square. Both the allocation and the current best estimate
(CBE) are shown, and the margin is defined as the additional rss error that could
Table 3.2 Top portion shows the allocated sensor and geophysical errors (left column) in terms
of v-polarized brightness temperature (T BV ) in Kelvin (K), and the Current Best Estimate (CBE)
(right column) for each measurement with 5.76s integration time. The radiometer CBE data are
based on the Aquarius instrument pre-launch calibration data. The margin is the additional RSS
error that could be included before exceeding the allocation. Bottom portion shows the monthly
RMS salinity error by latitude band based on the total error allocation of 0.38 K per sample. These
include the measurement sensitivity as it varies with SST and the number of samples averaged
per latitude band. The global RMS error allocation over all the latitude bands is 0.2 and CBE
0.15 (pss)
3 beam RMS (K)
Error sources
Allocation
CBE
Radiometer
0.15
0.13
Antenna
0.08
0.01
System pointing
0.05
0.02
Roughness
0.28
0.13
Solar
0.05
0.02
Galactic
0.05
0.04
Rain (Total liquid water)
0.02
0.01
Ionosphere
0.06
0.05
Atmosphere – other
0.05
0.02
SST
0.10
0.07
Antenna gain near land & ice
0.10
0.10
Model function
0.08
0.07
Brightness temperature error per observation
Baseline mission 3 beams RMS (K)
Allocation
CBE
Total RSS (K)
0.38
0.24
Margin RSS (K)
0.30
Baseline mission monthly salinity
error (psu)
Latitude range
Mean sensitivity
(dTv/dS)
Mean # samples
in 28 days
Allocation
CBE
0–10
0.756
10.9
0.15
0.10
11–20
0.731
11.3
0.16
0.10
21–30
0.671
12.1
0.16
0.10
31–40
0.567
13.5
0.18
0.12
41–50
0.455
15.9
0.21
0.13
51–60
0.357
20.3
0.24
0.15
61–70
0.271
30.2
0.26
0.16
Global RMS (pss)
0.20
0.13
Margin RSS (pss)
0.15