Liwen Pan, David P. Edwards, John C. Gille, Mark W. Smith, and James R. Drummond, "Satellite remote sensing of tropospheric CO and CH4: forward model studies of the MOPITT instrument," Appl. Opt. 34, 6976-6988 (1995)
The Measurements of Pollution in the Troposphere (MOPITT) instrument is designed to measure tropospheric CO and CH4 from a spaceborne platform by the use of infrared gas correlation radiometers. We describe the forward model that is used as the basis for the retrieval algorithm. We present the techniques used to model the instrument and describe the radiative transfer involved in the measurement process. Calculations have been performed to assess the sensitivity of the measured radiance to changes in the target-gas concentration profiles, changes in the concentration of contaminating constituents, and to variations in the parameters that describe reflection and emission of radiation at the Earth’s surface.
Jianguo Niu, Merritt N. Deeter, John C. Gille, David P. Edwards, Daniel C. Ziskin, Gene L. Francis, Alan J. Hills, and Mark W. Smith Appl. Opt. 43(24) 4685-4696 (2004)
Cathy Clerbaux, Juliette Hadji-Lazaro, Sébastien Payan, Claude Camy-Peyret, Jinxue Wang, David P. Edwards, and Ming Luo Appl. Opt. 41(33) 7068-7078 (2002)
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
4.7-μm CO Thermal-Band Typical Signals and Sensitivitya
Radiometer (mars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1/%)
NEΔq (% CO)
1
12.5–25
1.012 × 10−1
1.160 × 10−4
−6.32 × 10−7
22.47
2
25–50
1.009 × 10−1
3.579 × 10−4
−1.72 × 10−6
8.25
3
50–100
1.002 × 10−1
1.072 × 10−3
−3.96 × 10−6
3.59
4
200
9.839 × 10−2
3.257 × 10−3
−7.94 × 10−6
1.79
5
400
9.374 × 10−2
7.801 × 10−3
−9.74 × 10−6
1.46
6
200 DP
9.645 × 10−2
5.188 × 10−3
−9.08 × 10−6
1.56
7
400 DP
8.939 × 10−2
1.156 × 10−2
−9.00 × 10−6
1.58
8
800 DP
7.507 × 10−2
2.261 × 10−2
−6.60 × 10−6
2.15
Typical A- and D-signal values for several PMR’s and LMR’s for the thermal 4.7-μm CO profile measurement are given. Also shown is the change in D signal for a uniform 1% change in the CO mixing-ratio profile. This allows the NER to be expressed as a percentage change in the CO mixing-ratio profile (NEΔq) (radiometer’s NER = 1.42 × 10−5 W m−2 sr−1).
Table 2
2.3-μm CO Solar-Band Typical Signals and Sensitivitya
Radiometer (mbars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1/%)
NEΔq (%CO)
1
200
3.315 × 10−2
9.167 × 10−5
−8.56 × 10−8
43.46
2
400
3.308 × 10−2
1.890 × 10−4
−1.32 × 10−7
28.18
3
200 DP
3.309 × 10−2
1.683 × 10−4
−1.52 × 10−7
24.47
4
400 DP
3.295 × 10−2
3.462 × 10−4
−2.28 × 10−7
16.32
5
800 SP
3.388 × 10−2
4.013 × 10−4
−1.88 × 10−7
19.8
6
800 DP
3.266 × 10−2
7.133 × 10−4
−3.10 × 10−7
12.00
Typical A- and D-signal values for several PMR’s and LMR’s for the solar 2.3-μm CO total column measurement are given. Also shown is the change in D-signal for a 1% change in the CO column. This allows the NER to be expressed as a percentage change in the CO column amount (NEΔq) (radiometer’s NER = 3.72 × 10−6 W m−2 sr−1) (SP, single-passed).
Table 3
2.2-μm CH4 Solar-Band Typical Signals and Sensitivitya
Radiometer (mbars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1)
NEΔq (% CH4)
1
200 SP
1.40 × 10−1
4.89 × 10−4
−1.86 × 10−6
3.2
2
400 SP
1.39 × 10−1
1.09 × 10−3
−3.38 × 10−6
1.8
3
800 SP
1.39 × 10−1
2.41 × 10−3
−5.72 × 10−6
1.0
4
200 DP
1.40 × 10−1
9.61 × 10−4
−3.56 × 10−6
1.7
5
400 DP
1.39 × 10−1
2.13 × 10−3
−6.36 × 10−6
0.9
6
800 DP
1.37 × 10−1
4.63 × 10−3
−1.05 × 10−5
0.6
Typical A- and D-signal values for several PMR’s and LMR’s for the solar 2.2-μm CH4 total column measurement are given. Also shown is the change in D signal for a 1% change in the CH4 column. This allows the NER to be expressed as a percentage change in the CH4 column amount (NEΔq) (radiometer’s NER = 6.01 × 10−6 W m−2 sr−1).
Table 4
Additional Absorptions of Other Constituents for the 4.7-μm CO Thermal Banda
CO thermal 4.7-μm profile measurements of A and D radiometer signal sensitivities to gases other than CO are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CO-only atmosphere are presented. The percent difference (%Diff) is related to the total calculation.
Signals are in units of watts per inverse square meter per inverse steradian.
Table 5
Additional Absorptions of Other Constituents in the 2.3-μm CO Solar Banda
CO solar 2.3-μm total column measurements of A and D radiometer signal sensitivities to gases other than CO are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CO-only atmosphere are presented. The percent difference is related to the total calculation. The last column gives the percentage difference for the ratio of the D signal over the A signal.
Signals are in units of watts per inverse square meter per inverse steradian.
Table 6
Additional Absorptions of Other Constituents for the 2.2-μm CH4 Solar Banda
CH4 solar 2.2-μm total column measurements of A and D radiometer signal sensitivities to gases other than CH4 are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CH4-only atmosphere are presented. The percent difference is related to the total calculation. The last column gives the percentage difference for the ratio of the D signal over the A signal.
Signals are in units of watts per inverse square meter per inverse steradian.
Column 1 lists the radiometer configuration. Column 2 lists the change in the 4.7-μm D signal produced by a uniform 1% increase in the H2O mixing ratio. Column 3 lists the 4.7-μm D-signal change produced by a 1% increase in the CO mixing ratio divided by the change produced by a 1% increase in the H2O mixing ratio. Columns 4 and 5 repeat the information listed in columns 2 and 3, but for the 2.3-μm CO channel and for the ratio of the D signal to the A signal, rather than for the D signal only. Columns 6 and 7 repeat the information listed in columns 4 and 5, but for the 2.2-μm CH4 channel. All values are calculated with the U.S. standard atmosphere model.
Signals are in units of watts per inverse square meter per inverse steradian.
Tables (7)
Table 1
4.7-μm CO Thermal-Band Typical Signals and Sensitivitya
Radiometer (mars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1/%)
NEΔq (% CO)
1
12.5–25
1.012 × 10−1
1.160 × 10−4
−6.32 × 10−7
22.47
2
25–50
1.009 × 10−1
3.579 × 10−4
−1.72 × 10−6
8.25
3
50–100
1.002 × 10−1
1.072 × 10−3
−3.96 × 10−6
3.59
4
200
9.839 × 10−2
3.257 × 10−3
−7.94 × 10−6
1.79
5
400
9.374 × 10−2
7.801 × 10−3
−9.74 × 10−6
1.46
6
200 DP
9.645 × 10−2
5.188 × 10−3
−9.08 × 10−6
1.56
7
400 DP
8.939 × 10−2
1.156 × 10−2
−9.00 × 10−6
1.58
8
800 DP
7.507 × 10−2
2.261 × 10−2
−6.60 × 10−6
2.15
Typical A- and D-signal values for several PMR’s and LMR’s for the thermal 4.7-μm CO profile measurement are given. Also shown is the change in D signal for a uniform 1% change in the CO mixing-ratio profile. This allows the NER to be expressed as a percentage change in the CO mixing-ratio profile (NEΔq) (radiometer’s NER = 1.42 × 10−5 W m−2 sr−1).
Table 2
2.3-μm CO Solar-Band Typical Signals and Sensitivitya
Radiometer (mbars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1/%)
NEΔq (%CO)
1
200
3.315 × 10−2
9.167 × 10−5
−8.56 × 10−8
43.46
2
400
3.308 × 10−2
1.890 × 10−4
−1.32 × 10−7
28.18
3
200 DP
3.309 × 10−2
1.683 × 10−4
−1.52 × 10−7
24.47
4
400 DP
3.295 × 10−2
3.462 × 10−4
−2.28 × 10−7
16.32
5
800 SP
3.388 × 10−2
4.013 × 10−4
−1.88 × 10−7
19.8
6
800 DP
3.266 × 10−2
7.133 × 10−4
−3.10 × 10−7
12.00
Typical A- and D-signal values for several PMR’s and LMR’s for the solar 2.3-μm CO total column measurement are given. Also shown is the change in D-signal for a 1% change in the CO column. This allows the NER to be expressed as a percentage change in the CO column amount (NEΔq) (radiometer’s NER = 3.72 × 10−6 W m−2 sr−1) (SP, single-passed).
Table 3
2.2-μm CH4 Solar-Band Typical Signals and Sensitivitya
Radiometer (mbars)
A Signal (W m−2 sr−1)
D Signal (W m−2 sr−1)
ΔD Signal/%Δq (W m−2 sr−1)
NEΔq (% CH4)
1
200 SP
1.40 × 10−1
4.89 × 10−4
−1.86 × 10−6
3.2
2
400 SP
1.39 × 10−1
1.09 × 10−3
−3.38 × 10−6
1.8
3
800 SP
1.39 × 10−1
2.41 × 10−3
−5.72 × 10−6
1.0
4
200 DP
1.40 × 10−1
9.61 × 10−4
−3.56 × 10−6
1.7
5
400 DP
1.39 × 10−1
2.13 × 10−3
−6.36 × 10−6
0.9
6
800 DP
1.37 × 10−1
4.63 × 10−3
−1.05 × 10−5
0.6
Typical A- and D-signal values for several PMR’s and LMR’s for the solar 2.2-μm CH4 total column measurement are given. Also shown is the change in D signal for a 1% change in the CH4 column. This allows the NER to be expressed as a percentage change in the CH4 column amount (NEΔq) (radiometer’s NER = 6.01 × 10−6 W m−2 sr−1).
Table 4
Additional Absorptions of Other Constituents for the 4.7-μm CO Thermal Banda
CO thermal 4.7-μm profile measurements of A and D radiometer signal sensitivities to gases other than CO are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CO-only atmosphere are presented. The percent difference (%Diff) is related to the total calculation.
Signals are in units of watts per inverse square meter per inverse steradian.
Table 5
Additional Absorptions of Other Constituents in the 2.3-μm CO Solar Banda
CO solar 2.3-μm total column measurements of A and D radiometer signal sensitivities to gases other than CO are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CO-only atmosphere are presented. The percent difference is related to the total calculation. The last column gives the percentage difference for the ratio of the D signal over the A signal.
Signals are in units of watts per inverse square meter per inverse steradian.
Table 6
Additional Absorptions of Other Constituents for the 2.2-μm CH4 Solar Banda
CH4 solar 2.2-μm total column measurements of A and D radiometer signal sensitivities to gases other than CH4 are given. Results for a total radiance calculation that includes all atmospheric gases and a calculation for a CH4-only atmosphere are presented. The percent difference is related to the total calculation. The last column gives the percentage difference for the ratio of the D signal over the A signal.
Signals are in units of watts per inverse square meter per inverse steradian.
Column 1 lists the radiometer configuration. Column 2 lists the change in the 4.7-μm D signal produced by a uniform 1% increase in the H2O mixing ratio. Column 3 lists the 4.7-μm D-signal change produced by a 1% increase in the CO mixing ratio divided by the change produced by a 1% increase in the H2O mixing ratio. Columns 4 and 5 repeat the information listed in columns 2 and 3, but for the 2.3-μm CO channel and for the ratio of the D signal to the A signal, rather than for the D signal only. Columns 6 and 7 repeat the information listed in columns 4 and 5, but for the 2.2-μm CH4 channel. All values are calculated with the U.S. standard atmosphere model.
Signals are in units of watts per inverse square meter per inverse steradian.
Add to BibSonomy