Convective systems are responsible for energy transfers between the lower and upper atmospheric layers and play a fundamental role in the water cycle, weather and climate evolution. With a tandem of high resolution and wide swath all-sky atmospheric sounders, the C2OMODO concept allows the estimation of vertical dynamics within deep convective systems.

The Fine Resolution Explorer for Salinity, Carbon and Hydrology (FRESCH) is presented. The science case and the mission objectives are discussed before presenting the mission concept. FRESCH is an L-band antenna array operated in beamforming mode providing data at a spatial resolution of 10-15 km to study the biogeochemical and physical phenomena taking place at the interfaces of ocean, land and ice. FRESCH has been submitted to the European Space Agency Earth Explorer 12 program.

This paper reports on the main results of SMOS-HR instrument technical study, a new interferometric radiometer dedicated to Soil Moisture and Ocean Salinity measurement from space. The instrument aims at providing enhanced spatial resolution with respect to SMOS and integrating robust RFI (RF Interference) mitigation technique. The instrument key performance requirements and the architecture features and trade-offs are exposed in this paper.

Convective systems are responsible for energy transfers between the lower and upper atmospheric layers and play a fundamental role in the water cycle, weather and climate evolution. With a tandem of high resolution and wide swath all-sky atmospheric sounders, the C2OMODO concept allows the estimation of vertical dynamics within deep convective systems.

Recent applications of passive L-band observations from space are summarized for ocean, land surface and cryosphere applications. The main limitation of the measurements performed by the current generation of sensors is the spatial resolution. The need of a mission ensuring the continuation of L-band measurements from space with high spatial resolution (10-15 km) is discussed.

In the continuity of the existing SAPHIR microwave radiometer on-board Megha-Tropiques, in operation since 2011, a new generation atmospheric sounder is currently under study. SAPHIR-NG is designed to provide enhanced observations of clear sky water vapor and profiles of hydrometeors. The scientific objectives and requirements, as well as the instrumental implementation are described.

SAPHIR-NG is a new generation atmospheric sounder concept based on the existing SAPHIR instrument, onboard Megha-Tropiques, which has been operating since 2011. Its improvements with respect to SAPHIR are presented hereafter, both in terms of scientific objectives and instrumental architecture.

Current dual frequency altimeter designs with a SAR mode such as the SRAL altimeter on-board Sentinel 3 have a mass of around 60 kg and a mode dependent power consumption of 90 to 100 Watts. These are typical figures for state-of-the-art instruments of this kind. However, for a potential constellation of altimeters aiming at improving temporal and spatial coverage, the mass and the power consumption need to be drastically reduced in order to be compatible with cost effective micro-satellites that can accommodate around 40/50kg & 50/100W for the whole altimetry payload (altimeter, radiometer, POD GNSS receiver and laser reflector). Starting from these objectives, the study of a miniaturized altimeter operating in Ku-band and C-band (for ionosphere delay correction) with a combined radiometer-altimeter antenna was performed by Thales Alenia Space in the frame of two ESA contracts (one for the instrument and electronics design and one for the antenna). This study is an extensive and innovative reconsideration of the altimeter design, taking into account all the technical and technological possibilities to achieve the challenge of keeping high altimetry performances while targeting a drastic reduction of volume, of mass, of telemetry rate and especially of power consumption (identified as the main issue), assuming an altimetry mission operational at the horizon of 2020.