ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2017, Vol. 14, No. 5, pp. 268-277

Influence of the underlying surface on the accuracy of satellite differential radiometric measurements of water vapor profile in the lower troposphere

V.V. Sterlyadkin 1, 2 , E.V. Pashinov 2 , А.V. Kuzmin 2 , E.A. Sharkov 2 
1 Moscow Technology University, Moscow, Russia
2 Space Research Institute RAS, Moscow, Russia
Accepted: 07.07.2017
DOI: 10.21046/2070-7401-2017-14-5-2680-2770
The possibilities of a differential radiometry method for measuring water vapor profile in the 22 GHz band from a satellite are considered. The level of differential signals and their height selectivity are calculated. It is shown that the altitude selectivity of radiometric channels in the 183 GHz band, which are now widely used for satellite sounding of the humidity profile in the troposphere, is low, especially for the lower layer 0–4 km. This leads to low conditionality of the system of integral equations used in solving the inverse problem. The weighting functions of the differential signals, which have much better selectivity to the lower layers of the troposphere in the altitude interval 0–4 km are given. An estimation of the influence of uncertainty in the parameters of rough sea surface on the accuracy of differential methods is carried out. With a 20% deviation of the humidity profile from the standard, the response of the differential signals has a scale of about 1 K, while the uncertainty contributions of the temperature, salinity and surface wave data together make errors at a level of 0.25 K. This is due to the differential principle of measuring signals and is due to mutual subtraction of distorting factors at different frequencies. This feature of the proposed methods ensures stable convergence of the solution of the inverse problem and, in our opinion, allows us to use new differential measurement methods in the vicinity of the 22 GHz band to reconstruct the water vapor profile in the lower troposphere.
Keywords: measurement of atmospheric radiation, remote sensing, differential methods, water vapor, radiometric measurements, inverse problem, measurement of humidity from space, underlying surface
Full text


  1. Kutuza B.G., Danilychev M.V., Yakovlev O.I., Sputnikovyi monitoring Zemli: Mikrovolnovaya radiometriya atmosfery i poverkhnosti (Satellite Earth monitoring. Microwave radiometry of atmosphere and surface), Moscow: LENALEND, 2016, 336 p.
  2. Sterlyadkin V.V., Kosov A.S,. Opredelenie vertikal’nogo profilya vodyanogo para v atmosfere do 80 km po radioprosvechivaniyu trassy sputnik-zemlya (Determination of the vertical profile of water vapor in the atmosphere up to 80 km by radio transmission of the satellite-earth route), Issledovanie Zemli iz kosmosa, 2014, No. 3, pp. 14–24.
  3. Sterlyadkin V.V., Pashinov E.V., Kuzmin A.V., Sharkov E.A., Differentsial’nye radioteplovye metody vosstanovleniya profilya vlazhnosti atmosfery s borta kosmicheskikh apparatov (Differential radiothermal methods for reconstructing the atmospheric moisture profile from spacecraft), Issledovanie Zemli iz kosmosa, 2017, No. 2, pp. 64–76.
  4. Sterlyadkin V.V., Sharkov E.A., Differentsial’nye radioteplovye metody opredeleniya vertikal’nogo profilya vodyanogo para v troposfere i stratosfere Zemli (Differential radiothermal methods for determining the vertical profile of water vapor in the troposphere and stratosphere of the Earth), Issledovanie Zemli iz kosmosa, 2014, No. 5, pp. 15–28.
  5. Gohil B.S., Mathur A.K., Atmospheric humidity profile retrieval algorithms for Megha-Tropiques SAPHIR: a simulation study and analysis of AMSU-B data, Remote Sensing of the Atmosphere and Clouds: Proc. SPIE, 2006, Vol. 6408, pp. 640803-1–640803-9.
  6. Klein A., Swift C., An improved model for the dielectric constant of sea water at microwave frequencies, IEEE Trans. Antennas and Propagation, 1977, Vol. 25, No. 1, pp. 104–111.
  7. Mathur A.K., Gangwar R.K., Gohil B.S., Sanjib K.D., Prashant Kumar, Munn V. Shukla, Simon B., Pal P.K., Humidity profile retrieval from SAPHIR on-board the Megha-Tropiques, Current Science, 2013, Vol. 104, No. 12, pp. 1650–1655.
  8. Rosenkranz P.W., Water vapor microwave continuum absorption: A comparison of measurements and models, Radio Sciences, 1998, No. 33 (4), pp. 919–928.
  9. Sasaki Y., Asanuma I., Muneyama K., Naito G., Suzuki T., The dependence of sea-surface microwave emission on wind speed, frequency, incidence angle, and polarization over the frequency range from 1 to 49 GHz, IEEE Trans. Geosciences Remote Sensing, 1987, Vol. GE-25, No. 2, pp. 138.
  10. Sivira R.G., Brogniez H., Mallet C., Oussar Y., A layer-averaged relative humidity profile retrieval for microwave observations: design and results for the Megha-Tropiques payload, Atmospheric Measurement Techniques, 2015, No. 8, pp. 1055–1071.
  11. Weng F., Zou X., Introduction to Suomi national polar-orbiting partnership advanced technology microwave sounder for numerical weather prediction and tropical cyclone applications, J. Geophysical Research, 2012, No. 117, pp. 2156–2202.
  12. Westwater E.R., Schroeder J.A., Guide to microwave weighting function calculations, NOAA Technical Memorandum, ERL WPL-225, 1992.