Advanced Technology Microwave Sounder

The Advanced Technology Microwave Sounder (ATMS) is a 22-channel scanning microwave radiometer for observation of the Earth's atmosphere and surface. It is the successor to the Advanced Microwave Sounding Unit (AMSU) on NOAA weather satellites. ATMS units have been flown on the Suomi NPP and on the Joint Polar Satellite System. ^{[1] [2]}

Applications

ATMS measurements are assimilated into numerical weather prediction models ^{[3] [4] [5]} and atmospheric profiles retrieved by the combination of ATMS and the Cross-track Infrared Sounder on the same satellites are useful for synoptic scale meteorology. ^[6] Also, ATMS continues the record from its predecessor instruments MSU and AMSU of measurements in the 5-mm band of oxygen for monitoring of atmospheric temperature trends. ^[7]

Further information: Microwave Sounding Unit temperature measurements

Instrument characteristics

All of the channels are contained within one unit, unlike the AMSU which comprises two instruments (AMSU-A and AMSU-B). The radiometer's antenna scans underneath the satellite through nadir, and its polarization vector rotates with the scan angle. ^[1] The sampling rate satisfies the Nyquist criterion for channels 1-16; thus, images produced from the data are not aliased. ^[1] However, ATMS images exhibit striping, attributed to receiver gain fluctuations (1/f noise), ^[2] which can be removed by filtering the data. ^[8] Table 1 lists some characteristics of the ATMS channels.

Table 1 ATMS Radiometric characteristics ^[1]

Channel Number	Passband Center Frequency (GHz)	Polarization near nadir	Number of Passbands	Radiometric Resolution NEDT (K)	Primary Function
1	23.8	vertical	1	0.25	Water Vapor Burden
2	31.4	vertical	1	0.31	Water Vapor Burden
3	50.3	horizontal	1	0.37	Surface Emissivity, Precipitation
4	51.76	horizontal	1	0.28	Tropospheric Temperature
5	52.8	horizontal	1	0.28	Tropospheric Temperature
6	53.596 ± 0.115	horizontal	2	0.29	Tropospheric Temperature
7	54.4	horizontal	1	0.27	Tropospheric Temperature
8	54.94	horizontal	1	0.27	Temperature Near Tropopause
9	55.5	horizontal	1	0.29	Temperature Near Tropopause
10	57.290344	horizontal	1	0.43	Stratospheric Temperature
11	57.290344 ± 0.217	horizontal	2	0.56	Stratospheric Temperature
12	57.290344 ± 0.3222 ± 0.048	horizontal	4	0.59	Stratospheric Temperature
13	57.290344 ± 0.3222 ± 0.022	horizontal	4	0.86	Stratospheric Temperature
14	57.290344 ± 0.3222 ± 0.010	horizontal	4	1.23	Stratospheric Temperature
15	57.290344 ± 0.3222 ± 0.0045	horizontal	4	1.95	Stratospheric Temperature
16	88.2	vertical	1	0.29	Clouds/Snow
17	165.5	horizontal	1	0.46	Water Vapor
18	183.31 ± 7.0	horizontal	2	0.38	Water Vapor
19	183.31 ± 4.5	horizontal	2	0.46	Water Vapor
20	183.31 ± 3.0	horizontal	2	0.54	Water Vapor
21	183.31 ± 1.8	horizontal	2	0.59	Water Vapor
22	183.31 ± 1.0	horizontal	2	0.73	Water Vapor

Notes

• "Vertical polarization near nadir" (also known as quasi-vertical) means that for this cross-track scanning arrangement, the E-vector is parallel to the scan direction when the antenna views nadir; "horizontal polarization" means the orthogonal direction.
• The NEDT values were measured on the Suomi-NPP unit. Two subsequent units showed similar or slightly better noise performance. ^[2]

References

1. Kim, E.; Lyu, C.-H. J.; Anderson, K.; Leslie, R. V.; Blackwell, W. J. (2014), "S-NPP ATMS instrument prelaunch and on-orbit performance evaluation", J. Geophys. Res. Atmos., 119 (9): 5653–5670, Bibcode:2014JGRD..119.5653K, doi: 10.1002/2013JD020483 , hdl: 2060/20140017425
2. Kim, E.; et al. (2020). Pre-launch performance of the Advanced Technology Microwave Sounder (ATMS) on the Joint Polar Satellite System-2 Satellite (JPSS-2). International Geoscience and Remote Sensing Symposium. Waikoloa, HI, USA. pp. 6353–6. doi:10.1109/IGARSS39084.2020.9324605.
3. Bormann, N.; Fouilloux, A.; Bell, W. (2013), "Evaluation and assimilation of ATMS data in the ECMWF system", J. Geophys. Res. Atmos., 118 (23): 12, 970–80, Bibcode:2013JGRD..11812970B, doi: 10.1002/2013JD020325
4. Weng, F.; Zou, X.; Wang, X.; Yang, S.; Goldberg, M. (2012), "Introduction to Suomi national polar-orbiting partnership advanced technology microwave sounder for NWP and tropical cyclone applications", J. Geophys. Res., 117: D19112, doi: 10.1029/2012JD018144
5. Zhu, Y.; Liu, E.; van Delst, P.; Gayno, G.; Purser, J.; Su, X. (2017), "Latest Progress of All-Sky Microwave Radiance Assimilation in the GSI and the CRTM at NCEP", JCSDA Quarterly (55): 13–21, doi: 10.7289/V5V98648
6. Nalli, N.R.; et al. (2016), "Satellite sounder observations of contrasting tropospheric moisture transport regimes: Saharan air layers, Hadley cells, and atmospheric rivers", J. Hydrometeorol., 17 (12): 2997–3006, Bibcode:2016JHyMe..17.2997N, doi: 10.1175/JHM-D-16-0163.1
7. Zou, C-Z.; Goldberg, M.D.; Hao, X. (2018), "New generation of U.S. satellite microwave sounder achieves high radiometric stability performance for reliable climate change detection", Sci. Adv., 4 (10): eaau0049, Bibcode:2018SciA....4...49Z, doi: 10.1126/sciadv.aau0049 , PMC   6192683 , PMID   30345359
8. Ma, Y.; Zou, X. (2015), "Striping noise mitigation in ATMS brightness temperatures and its impact on cloud LWP retrievals", J. Geophys. Res. Atmos., 120 (13): 6634–53, Bibcode:2015JGRD..120.6634M, doi: 10.1002/2015JD023162

External links

• https://www.jpss.noaa.gov/atms.html Archived 2022-01-20 at the Wayback Machine