L-band observations have been shown as the optimum technique for estimating soil moisture and ocean salinity variables to study the land surface and ocean. The European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) mission was the first (2009-present) spaceborne L-band radiometer. This was followed by two L-band missions flown by the National Aeronautics and Space Administration (NASA) to measure sea surface salinity (Aquarius 2011-2015) and soil moisture (SMAP 2015-present). It is critical to continue the time series of L-band observations and have a long term L-band soil moisture and ocean salinity data records. To address this need we propose a new low-cost instrument concept known as the Global L-band active/passive Observatory for Water cycle Studies (GLOWS) that will include an L-band radiometer and radar to provide data continuity. The new mission concept includes a deployable reflectarray lens antenna with a compact feed that can be flown on an Earth Venture class satellite in a EELV Secondary Payload Adapter (ESPA) Grande-class mission. GLOWS will continue the science observations of SMAP and SMOS at the same resolution and accuracy at substantially lower cost, size, and weight.
In this presentation we describe the GLOWS mission concept and system design. It has been long been assumed that the large antenna aperture required for high resolution L-band measurements requires a large spacecraft, with a correspondingly large cost. However, the new proposed antenna configuration enables L-band radar and radiometer observations with the required performance that can be flown on a small satellite. Key to the new concept is new deployable lens antenna with a compact feed. We present our progress in demonstrating key hardware elements and antenna design. The science goals of the GLOWS mission for continuing the L-band climate series and the synergy with CIMR mission will be presented.

The Investigation of Convective Updrafts (INCUS) is a recently selected NASA Earth Ventures Mission. The overarching goal of INCUS is to understand why, when and where tropical convective storms form, and why only some storms produce extreme weather. Life on Earth is bound to convective storms, from the fresh water they supply to the extreme weather they produce. Convective storms facilitate much of the vertical transport of water and air, a property typically referred to as convective mass flux (CMF), between Earth’s surface and the upper troposphere. CMF within tropical convective storms plays a critical role in the weather and climate system through its influence on storm intensity, precipitation rates, upper tropospheric moistening, high cloud feedbacks, and the large-scale circulation. Recent studies have also suggested that CMF may change with changing climates. In spite of the critical role of CMF in the weather and climate system, much is not understood regarding the way in which various environmental factors govern this mass transport, nor the subsequent impacts of CMF on high clouds and extreme weather. Representation of CMF is also a major source of error in weather and climate models, thereby limiting our ability to predict convective storms and their associated feedbacks on weather through climate timescales.

INCUS is a NASA class-D mission. It is comprised of three RainCube-heritage Ka-band 5-beam scanning radars that are compatible with SmallSat platforms. The satellite platforms will be 30 and 90 seconds apart. Each SmallSat will carry one radar system each, and the middle SmallSat will house a single TEMPEST-D-heritage cross-track-scanning passive microwave radiometer with four channels between 150 and 190 GHz. Through its novel measurements of time-differenced profiles of radar reflectivity, INCUS is the first systematic investigation of the rapidly evolving CMF within tropical convective storms. The primary INCUS objectives are: (1) to determine the predominant environmental properties controlling CMF in tropical convective storms; (2) to determine the relationship between CMF and high anvil clouds; (3) to determine the relationship between CMF and the type and intensity of the extreme weather produced; and (4) to evaluate these relationships between CMF and environmental factors, high anvil clouds, and extreme weather within weather and climate models. The ground breaking observations of INCUS are expected to significantly enhance our understanding and prediction of extreme weather in current and future climates.

Monitoring the Earth Radiation Budget (ERB) and in particular the Earth Energy Imbalance (EEI), is of paramount importance for a predictive understanding of global climate change [Hansen et al, 2011], [Von Schuckmann et al, 2016], [Dewitte & Clerbaux, 2018], [Dewitte et al, 2019], [Dewitte, 2020]. Currently the ERB is monitored by the NASA CERES program [Wielicki et al, 1996], [Loeb et al, 2018] from the complementary morning and afternoon sun synchronuous orbits. The only CERES instrument in the morning orbit flies on the Terra satellite since 2000, and has no foreseen US follow-on mission. We propose the European follow-on mission Advanced Solar-TERrestrial Imbalance eXplorer (ASTERIX), based on proven technology, that allows progress in accuracy and stability, and that can be accomodated in a 6U cubesat.

The Earth Energy Imbalance (EEI) is defined as the small difference between the two nearly equal terms of the incoming solar radiation, and the outgoing terrestrial radiation lost to space. Making a significant measurement of the EEI from space is very challenging, and requires a differential measurement with one single instrument of both the incoming solar radiation and the outgoing terrestrial radiation. The instrument that allows such a differential measurement is an improved wide field of view electrical substitution cavity radiometer [Schifano et al, 2020a]. The estimated accuracy in a stand-alone earth observation mode is 0.44 W/m2. A demonstration of the differential sun-earth measurement can be made with the flat sensors of the UVQSsat [Meftah et al, 2020], currently in space.

The wide field of view radiometer will observe the earth from limb to limb. A single measurement footprint is a circle with a diameter around 6300 km. For the discrimination of cloudy and clear skies, a higher spatial resolution is needed. This will be obtained from two wide field of view cameras, a visible wide field of view camera for the characterisation of the spatial distribution of the reflected solar radiation [Schifano et al, 2020b], and a thermal infrared wide field of view camera for the characterisation of the spatial distribution of the emitted thermal radiation [Schifano et al, 2021].

The visible wide field of view camera is based on a flight proven Commercial Of The Shelf (COTS) RGB CMOS camera, completed with a custom designed or COTS wide field of view lens. For our current conceptual design [Schifano et al, 2020b], the estimated resolution is 2.2 km at nadir, and the estimated stand-alone accuracy is 3 %. We have assembled and characterised a COTS prototype of the wide field of view thermal camera.

The thermal wide field of view camera is based on a flight proven Commercial Of The Shelf (COTS) microbolometer array, completed with a custom designed or COTS wide field of view lens. For our current conceptual design [Schifano et al, 2021], the estimated resolution is 4.4 km at nadir, and the estimated stand-alone accuracy is 5 %. We are currently testing a prototype of the TIRI thermal camera [Okada et al, 2021] for the HERA asteroid mission.
We are currently studying the sampling of the ERB from different satellite orbits [Hocking et al, 2021], as a first step towards the end to end simulation of the ASTERIX mission.

References

[Hansen et al, 2011] Hansen, J., Sato, M., Kharecha, P., & Schuckmann, K. V. (2011). Earth's energy imbalance and implications. Atmospheric Chemistry and Physics, 11(24), 13421-13449.
[Von Schuckmann et al, 2016] Von Schuckmann, K., Palmer, M. D., Trenberth, K. E., Cazenave, A., Chambers, D., Champollion, N., ... & Wild, M. (2016). An imperative to monitor Earth's energy imbalance. Nature Climate Change, 6(2), 138-144.
[Dewitte & Clerbaux, 2018] Dewitte, S., Clerbaux, N. (2018). Decadal Changes of Earth’s Outgoing Longwave Radiation.
[Dewitte et al, 2019] Dewitte, S., Clerbaux, N., Cornelis, J. (2019). Decadal changes of the reflected solar radiation and the earth energy imbalance.
[Dewitte, 2020] Dewitte, S. (2020). Editorial for Special Issue “Earth Radiation Budget”.
[Wielicki et al, 1996] Wielicki, B. A., Barkstrom, B. R., Harrison, E. F., Lee III, R. B., Smith, G. L., & Cooper, J. E. (1996). Clouds and the Earth's Radiant Energy System (CERES): An earth observing system experiment. Bulletin of the American Meteorological Society, 77(5), 853-868.
[Loeb et al, 2018] Loeb, N. G., Doelling, D. R., Wang, H., Su, W., Nguyen, C., Corbett, J. G., ... & Kato, S. (2018). Clouds and the earth’s radiant energy system (CERES) energy balanced and filled (EBAF) top-of-atmosphere (TOA) edition-4.0 data product. Journal of Climate, 31(2), 895-918.
[Schifano et al, 2020a] Schifano, L., Smeesters, L., Geernaert, T., Berghmans, F., Dewitte, S. (2020). Design and analysis of a next-generation wide field-of-view earth radiation budget radiometer. Remote Sensing, 12(3), 425.
[Meftah et al, 2020] Meftah, M., Damé, L., Keckhut, P., Bekki, S., Sarkissian, A., Hauchecorne, A., Bui, A. (2020). UVSQ-SAT, a pathfinder cubesat mission for observing essential climate variables. Remote Sensing, 12(1), 92.
[Schifano et al, 2020b] Schifano, L., Smeesters, L., Berghmans, F., Dewitte, S. (2020). Optical system design of a wide field-of-view camera for the characterization of earth’s reflected solar radiation. Remote Sensing, 12(16), 2556.
[Schifano et al, 2021] Schifano, L., Smeesters, L., Berghmans, F., Dewitte, S. (2021). Wide-field-of-view longwave camera for the characterization of the earth’s outgoing longwave radiation. Sensors, 21(13), 4444.
[Okada et al, 2021] Okada, T., Tanaka, S., Sakatani, N., Shimaki, Y., Arai, T., Senshu, H., ... & Karatekin, Ö. (2021). Thermal infrared imaging experiment of S-type binary asteroids in the Hera mission (No. EPSC2021-317). Copernicus Meetings.
[Hocking et al, 2021] Hocking, T., Dewitte, S., Mauritsen, T., Megner, L., Schifano, L. (2021, September). How can the Earth energy imbalance be measured over the coming decades?. In CFMIP 2021 Virtual Meeting.

TreeView is an Earth Observation mission that will achieve precision forestry from space in support of Nature-Based Solutions to tackle climate change. The expansion of tree cover is a critical component of the path to net zero but reaching this target will require extensive management of this resource. Through leveraging next-generation optical sensor technology and innovations across the payload and spacecraft development, TreeView will provide multispectral data at a ground sampling resolution on the scale of individual trees, providing measurement and monitoring capabilities at an unprecedented level.
TreeView is a New Space mission where innovation is being used to lower the costs and time to deliver the mission. In the spacecraft, In-Space Missions’ cube-scale Faraday 2G platform, utilising proven sub-systems in a scalable satellite, is the baseline for the payload. The payload is led by The Open University working with UK industry on the telescope, electronics and detector. The sensor is the latest earth observation multispectral high-resolution sensor from Teledyne UK, designed to address very high-resolution imaging requirements. The ground segment data analysis will utilise an extensive database for validation of the data.
TreeView has been funded through to a Preliminary Design Review by the UK Space Agency’s National Space Innovation Programme. This exciting mission aims to deliver a new perspective on urban green infrastructure in the UK and internationally and assess the health of larger forest stands.
The mission has a challenging target of an end-to-end budget of £15M and to achieve this, cost, size, weight and power limits are imposed on the payload and spacecraft. Meanwhile, signal to noise performance, spatial and spectral resolution have been set to provide new and unique data not available from Sentinel-2 or commercial providers.
This talk will give an overview of the space and ground segments under development, and will outline the data products that will be generated by the mission.

The GRASP-AirPhoton commercial partnership is producing a highly capable multi-angle polarimeter (GAPMAP) for Earth observations. The instruments are inspired by the HyperAngle Rainbow Polarimeter (HARP) that has been orbiting Earth in a 3U cubesat and making measurements with proven calibration that makes true scientific use of the data possible. The GAPMAPers constellation will measure each pixel of the Earth at multiple wavelengths, multiple angles and in multiple polarization states. This wealth of calibrated data allows for detailed characterization of aerosol, cloud and surface properties. GAPMAP-0 will be the vanguard of a proposed constellation of small satellites with payloads designed to facilitate commercial reproduction and maintain high capability. This first demonstration sensor will fly aboard the Spire Adler-2 6U cubesat to be launched at the end of 2022 funded by Findus Venture. The commercial venture will offer a range of data products, going well beyond simple imagery, to include retrieved Level 2 aerosol and surface characterization using the Generalized Retrieval of Aerosol and Surface Properties (GRASP) retrieval algorithm. GRASP SAS aim to the use of chemical transport models at global, regional and local scale to retrieve sources of emissions and atmospheric dynamics. Targeted customers include air quality, agricultural communities and other customers needing surface products and atmospheric characterization that can be obtained economically from a constellation of small satellites.

Taking advantage from the lessons learnt on the Swarm’s Absolute Scalar Magnetometers (ASM), a new generation of optically pumped helium scalar magnetometer also delivering calibrated vector measurements is currently being developed for the NanoMagSat satellites. A very significant miniaturization has been made possible for both the sensor head and the associated electronics, thanks to the replacement of the fiber laser by a laser diode and the definition of a new architecture to ensure the instrument’s isotropy. These evolutions also imply modifying the signal detection scheme, thus leading to a completely revised design. Special emphasis will be put on the performance evolution opened by these changes. Given the results obtained by the ASMs flown on Swarm satellites respectively in vector and burst modes, this Miniaturized Absolute Magnetometer (MAM) will be operated to simultaneously deliver high accuracy vector measurements at a 1 Hz rate and high resolution scalar measurements at 2 kHz. In addition to the MAM, a High Frequency Magnetometer (HFM) delivering high-resolution (# 0,2 pT/Hz1/2 @ 1 Hz) vector data at a 2 kHz rate will be operated to support space weather related studies. It derives from a magnetometer developed at Leti for MagnetoEncephaloGraphy applications in shielded environments, which has been successfully adapted for operation in the Earth magnetic field. Finally, to allow in-orbit cross analyses of small scale structures - typically down to a few meters - magnetic measurements by both the MAM and the HFM will be synchronized with the plasma parameters delivered by the multi needle Langmuir probe (m-NLP) developed by the University of Oslo, which complements the NanoMagSat science payload. We will report here on the development status of these two MAM and HFM magnetometers and describe the results obtained so far, as well as the work still lying ahead.