V.S. Etkin

The determination of sea surface wind and temperature with airborne radiometric data

Deals with preliminary results of the Joint US/Russia Internal Wave Remote Sensing Experiment (PreCHERI). The airborne radiometric (RM) complex and side-looking real aperture radar (RAR) are briefly described. The algorithms of sea surface temperature and surface wind restoration from RM data are outlined. The results of reconstruction are compared with true surface data. The standard deviation for wind direction is /spl Deltaspl Phi/=5.3/spl deg/(for wind speed /spl Delta/v=0.43 m/s; and for temperature /spl Delta/T=0.38 degC). The comparison of RH data with RAR pictures shows a good agreement of backscatter in VV-polarization with the value of polarizational anisotropy in RM channels. It is concluded that combined analysis of RM and RAR data enables significantly improved algorithms to be developed for ocean remote monitoring.<<ETX>>

Investigations of the hydrobiological situation in Lake Onega using joint spaceborne radar, airborne and in situ measurements

Abstract The results of the first comprehensive limnological experiment conducted in Lake Onega in the summer of 1989 are presented. The concurrent spacebornc observations (Cosmos-l870 SAR), airborne surveys (visual observations and IR radiometry), and shipborne observations (visual observations, thermal and optical water characteristics), made it possible to establish the presence of vast regionsof phytoplankton in the lake. It is shown that the activity of phytoplankton may change water surface conditions, thus causing strong radar signal contrasts.

Shipborne microwave radiometer and scatterometer measurements of sea surface patterns during Joint US/Russia Remote Sensing Experiment

Presents results of microwave radio brightness temperature and back scattering measurements of the sea surface which were conducted from a research vessel. The paper discusses the analysis of data obtained from the investigation of internal wave surface manifestations as well as atmospheric stratification stability impact on the microwave radiometer and scatterometer signal patterns. The present paper also describes the conditions and methods of ship measurements and microwave instruments used.<<ETX>>

The Russian project "Space study of the Earth as an ecological system and human impact on this system" (Program ECOS): main goals and new remote sensing systems

The Russian ECOS program for Earth global processes monitoring is discussed. This program started with KOSMOS-1870 (1987) and ALMAZ-1 (1991) satellites and will be supported by ALMAZ-1B and ALMAZ-2 spacecrafts, by PRIRODA unit of the manned MIR orbital station, by few smaller satellites, and MIR-NASA and ALPHA programs. The largest satellites are to be equipped by multifunctional high resolution radars, microwave radiometers (radiometric complex PARC is described) and by optical and IR devices. The main goal of the project ECOS is to study the Earth as an integrated selforganizing climatic-ecological system subject to human impact. It means that all the natural media: Hydrosphere, Atmosphere, Cryosphere, Lithosphere and Biosphere are to be studied and their interactions. The results of optical, IR and microwave studies are expected to provide data for development improved prognostic models for global climatic change. Microwave remote sensing data on wind waves, water temperature, near water wind speed, evaporation rate, rains, internal waves, fronts, currents, vortices etc. are of great importance. These data may improve our representations of the global temperature change and give additional impulse to the study global bifurcation processes which may abruptly change global and/or local state of the Earth climatic-ecological system. Suggestions are presented how to integrate the Russian ECOS program with international programs like Mission to Planet Earth.

Remote sensing and contact studies of phytoplankton in Lake Onega

Abstract The results of the first combined limnological experiment conducted in Lake Onega in the summer of 1989 are presented. The concurrent spaceborne (Cosmos-1870 SAR), airborne (visual observations and IR radiometry), and shipborne (visual observations, thermal and optical water characteristics) surveys made it possible to establish the presence of vast phytoplankton regions in the lake. It is shown that the activity of phytoplankton may change water surface conditions, thus causing strong radar signal contrasts.

The determination of atmospheric water vapour content using dual-frequency radiometer

The results of aircraft microwave K- and K/sub a/-band radiometer measurements used for liquid water and water vapour content recovering are presented. The K-band dual-frequency radiometer has been developed in Space Research Institute (Russia). This radiometer provides simultaneous measurements of brightness temperature in two frequency bands due to adjustable dual-frequency filter. The comparison of results obtained by two different retrieval techniques shows good agreement, so also under strong cloud condition.<<ETX>>