1. Draft plan about lunar calibration for FY-3 MWHS
Gu Songyan, Guo Yang, Wu Ronghua, Sun Fenglin,
Wu Qiong and Dou Fangli.
National Satellite Meteorological Center,
China Meteorological Administration
(NSMC/CMA)

2. 1 Background
OUTLINE
2 Moon glint in MWHS
3 Microwave Moon—MicM
4 Draft plan

3. 1 Backgroud ok Microwave Temperature Sounder (MWTS) 13 channels
(AMSU-A)
Microwave
Radiation Imager
10 channels
Microwave
Humidity
Sounder (MWHS)
15channels with channels at
118 GHz
(MHS)
We have launched 4 fy-3 satellites, fy-3/a/b/c, and d. There are 3 microwave instruments board on fy-3 satellites, they are MWRI, MWTS, and MWHS.All of them have the two points calibration system of space view and warm target view on orbit. Just like optical instruments, they all make an inclusive of non-lineary system response.

4. Atmospheric Transmission at Microwave Wavelengths
MWHS2

5. Central Frequency (GHz)
WMHSⅡ
Parameter
Specification
Scan Angle
±53.35°
Pixels Per Scan Line 98
Quantization
14 bits
Ch No.
Central Frequency (GHz)
Polarization
Bandwidth (MHz)
Freq. Stability (MHz)
Dynamic Range
(K)
NEΔT(K)
Cal. Acc.
Main Beam Width
Main Beam Eff.
Purpose 1
89.0 V
1500 50
3－340
1.0
1.3
2.0°
>92%
Surface and Precipitation 2
118.750.08 H 20 30
3.6
2.0
Atmospheric Temperature Profile 3
118.750.2
100 4
118.750.3
165
1.6 5
118.750.8
200 6
118.751.1 7
118.752.5 8
118.753.0
1000 9
118.755.0
2000 10
150.0
1.1°
>95% 11
183.31±1
500
Atmospheric Moisture Profile 12
183.31±1.8
700 13
183.31±3 14
183.31±4.5 15
183.31±7
2018/12/10

6. The NEdT from FY3A to FY3C is improved much
FY-3C Specification
FY-3C On-orbit
FY-3B On-orbit
FY-3A On-orbit
Channels
Peak nonlinearity /K
Channels

8. FY-3C/MWHS CALIBRATION RESULTS
Cross-compare with ATMS
（O-B）
Site calibration at Puer
FY3C MWHS（II）
Soumi/NPP ATMS
通道号
标准差
（K）
CH1
4.03
CH16
3.49
CH2
0.43 --
CH3
0.23
CH4
0.29
CH5
0.27
CH6
0.48
CH7
1.8
CH8
2.26
CH9
3.6
CH10
3.06
CH17
3.45
CH11
1.36
CH22
1.33
CH12
1.47
CH21
1.34
CH13
1.7
CH20
1.57
CH14
2.08
CH19
1.93
CH15
2.39
CH18
2.44 通道
标准差
（K） 11
0.947 12
0.8183 13
0.8603 14
0.9516 15
0.9361

9. 2 Moon glint in MWHS 9 MOON 3 warm target views 黑体 MWHS 3 space views
98 earth views
3 space views 黑体
MWHS
MOON
3 warm target views 9

10. 2 Moon glint in MWHS Space view Space view Scan line number

11. 2 Moon glint in MWHS
SPACE VIEW
SP COUNT
Ch1
Ch2
Ch3
LINE NUMBER

12. Lunar glint identification

13. From Yang Hu

14. NESDIS interpolation using Smooth Curve

15. Before correction
After correction
Sub-point BT
Space view DN

16. 150GHz
89GHz
118GHz-8
183GHz-4

17. FY-3C/MWHS CALIBRATION RESULTS
Cross-compare with ATMS
（O-B）
Site calibration at Puer
FY3C MWHS（II）
Soumi/NPP ATMS
通道号
标准差
（K）
CH1
4.03
CH16
3.49
CH2
0.43 --
CH3
0.23
CH4
0.29
CH5
0.27
CH6
0.48
CH7
1.8
CH8
2.26
CH9
3.6
CH10
3.06
CH17
3.45
CH11
1.36
CH22
1.33
CH12
1.47
CH21
1.34
CH13
1.7
CH20
1.57
CH14
2.08
CH19
1.93
CH15
2.39
CH18
2.44 通道
标准差
（K） 11
0.947 12
0.8183 13
0.8603 14
0.9516 15
0.9361

18. 3 Microwave Moon
Ground-based microwave measurements of the Moon have been studied at wavelengths of 1–500 cm since 1960s (Battaglia, 2003; Hirth et al., 1976; Keihm and Gary, 1979; Morabito et al., 2008; Schloerb et al., 1976). However, such observations have a number of drawbacks as:
(i) they cannot observe the far side of the Moon;
(ii) the spatial resolution is much lower than what can be done by a lunar satellite;
(iii) due to the presence of limb effects, interpretation of off-center data are much more difficult.
TB of the Moon and its characteristics were investigated theoretically and predicted by a number of authors (Fa and Jin, 2007a; Gary and Keihm, 1978; Hagfors, 1971; Keihm, 1982; Keihm and Gary, 1979; Muhleman, 1972).
Interpretations of ground-based lunar microwave measurements were done based on different lunar regolith models (Feng et al., 2010; Keihm and Cutts, 1981; Schloerb et al., 1976).
Passive orbital microwave measurements at different frequencies were proposed since the 1980s (Keihm, 1984), with the expectation that they could lead to the knowledge of global lunar heat flow and average regolith thickness. This thermal information, which is not available through active radar images of the Moon obtained by recent lunar orbiters Kaguya (Ono et al., 2009) and Chandrayaan-1 (Spudis et al., 2010), could provide important clues to understand the thermal evolution of the Moon and provide reliable estimation of valuable lunar resources, such as helium-3, due to their dependence on the thickness of regolith (Fa and Jin, 2007b).
Passive microwave observation can sense emission from below the lunar surface (possibly down to 10 m, depending on the dielectric properties of the lunar regolith), and is able to “see” the permanently shadow region in the poles and the Moon at night regardless of solar illumination.

19. Chinese Chang’E-1 (CE-1)
Among recent lunar orbiters, only the Chinese Chang’E-1 (CE-1) was equipped with a passive microwave radiometer (MRM) to measure the natural microwave emission from the lunar surface. The microwave emission, characterized by a frequency-dependent brightness temperature (TB), is related to the physical temperature and dielectric properties of the lunar surface. By measuring the brightness temperature at different frequencies, detailed thermal behavior and properties of the lunar surface can be retrieved. Using CE-1’s microwave data, we present here a set of microwave maps of the Moon constructed through a rescaling of TB to noontime or midnight
CE-1 launched in

20. Information about MRM Frequencies (GHz) 3.0 (±1%) 7.8 (±1%)
19.35 (±1%)
37 (±1%)
Bandwidth (MHz)
100 (±15%)
200 (±15%)
500 (±15%)
Integration time (ms)
Temperature sensitivity (K)
⩽0.5
Linearity
⩾0.99
3 dB beam width
E:15 ± 2°
E:9 ± 2°
E:10 ± 2°
H:12 ± 2°
H:9 ± 2°
H:10 ± 2°
Footprint (from 200 km orbital altitude) (km) 56 30

21. 3 Microwave Moon---MicM

22. 3 Microwave Moon---MicM

23. Central Frequency (GHz)
4 Draft plan
Inter-channel calibration for oxygen absorption channels at 118GHz
Ch No.
Central Frequency (GHz)
Polarization
Bandwidth (MHz)
Freq. Stability (MHz)
Dynamic Range
(K)
NEΔT(K)
Cal. Acc.
Main Beam Width
Main Beam Eff.
Purpose 1
89.0 V
1500 50
3－340
1.0
1.3
2.0°
>92%
Surface and Precipitation 2
118.750.08 H 20 30
3.6
2.0
Atmospheric Temperature Profile 3
118.750.2
100 4
118.750.3
165
1.6 5
118.750.8
200 6
118.751.1 7
118.752.5 8
118.753.0
1000 9
118.755.0
2000 10
150.0
1.1°
>95% 11
183.31±1
500
Atmospheric Moisture Profile 12
183.31±1.8
700 13
183.31±3 14
183.31±4.5 15
183.31±7

24. Put the ch (3) as a reference channel, and transfer the ref
Put the ch (3) as a reference channel, and transfer the ref. to others by lunar views, to optimize the calibration results.
FY-3C Specification
FY-3C On-orbit
FY-3B On-orbit
FY-3A On-orbit
Channels

25. SV DN during the Moon appearing in the field of space view
Deep Space view DN
SV DN during the Moon appearing
in the field of space view
Reference DSV DN
Scan line
Rsp(moon,ch1), ……,Rsp(moon,chn) Rsp(moon,reference)
Rsp(moon,chm)=Rsp(moon,reference) +△R(chm) (m=1,2,…,n)

26. Central Frequency (GHz)
Ch No.
Central Frequency (GHz)
Main Beam Width
Main Beam Eff.
Purpose 1
89.0
2.0°
>92%
Surface and Precipitation 2
118.750.08
Atmospheric Temperature Profile 3
118.750.2 4
118.750.3 5
118.750.8 6
118.751.1 7
118.752.5 8
118.753.0 9
118.755.0 10
150.0
1.1°
>95% 11
183.31±1
Atmospheric Moisture Profile 12
183.31±1.8 13
183.31±3 14
183.31±4.5 15
183.31±7
Bandwidth (MHz)
1500 20
100
165
200
1000
2000
500
700
MWHS: total power radiometer

27. Brightness tem./K Warm target Moon target C DSV 0º 90º 180±2º 270º
53.35º
287±2º
DSV
306.65º
earth scene
Brightness tem./K DN
Warm target B A
Space point
282K
2.73K
moon
Moon target C
DN(space view)
DN(moon view)
DN(warm view)

28. ---- antennas mismatch
4 Draft plan
(2) Lifetime stability checks of MWHS
(3) Pointing bias evaluation for two antenna systems of 118GHz and 183GHz.
---- antennas mismatch

29. Bridge the lunar BT (2.730K,150K) to the T/V test results over (80K,310K) and then getting the system respond over whole dynamic range of (2.73K,310K).
Extrapolate the T/V test results of(80K,310K) to (2.73K,310K)

30. 谢谢!
Thank you!

31. f0-df f f+df

33. SNO ( FY3/MWHS and NPP/ATMS at 183GHz)