The International Combination Service for Time-variable Gravity Fields (COST-G) is a Product Center of IAG’s International Gravity Field Service (IGFS). COST-G provides consolidated monthly global gravity fields in terms of spherical harmonic coefficients and thereof derived grids of surface mass changes by combining existing solutions or normal equations from COST-G analysis centers (ACs) and partner analysis centers (PCs). The COST-G ACs adopt different analysis methods but apply agreed-upon consistent processing standards to deliver time-variable gravity...

Sentinel-6 is an Earth Observation satellite constellation part of the EU Copernicus Programme developed by ESA, operated by EUMETSAT in collaboration with NASA, NOAA and CNES. The first satellite of the Sentinel-6 constellation (Sentinel-6 Michael Freilich, S-6 MF in short) has been launched on 21 November 2020. The S6-MF satellite embarks as main scientific payload the sensor Poseidon-4 (POS4) which is a dual frequency redundant radar altimeter. It represents a significant breakthrough with respect to...

The Copernicus Sentinel-3 Surface Topography Mission (STM), based on a constellation of two satellites, provides extremely valuable surface elevation information over inland waters, sea ice and land ice, thanks to its SAR altimeter which retrieves high-resolution along-track elevation measurements, and to its orbit that covers high-latitude polar regions. To ensure that these measurements can be used with confidence, and to maximize the return on investment of the Copernicus Sentinel-3 STM, adequate validation of the geophysical...

Many improvements were realized in the last years concerning DORIS and DIODE in particular. The DIODE v5.05 is in operation aboard Jason-3, Sentinel 3A and 3B since mid-2022, improving the performances of the real-time navigation. This new version, also aboard the next flying mission SWOT, will deliver for the altimeter KaRin a geodetic bulletin of high precision for the next 20 seconds. This presentation will focus on these improvements and will give some ideas for...

With the launch of Sentinel-3A (2016) and Sentinel-3B (2018), the Copernicus programme has a constellation of two SAR altimeters, which provides an operational access to inland Water Surface Height (WSH) data (i.e., lakes and rivers), with outstanding product performance and data coverage. To further improve the performance of the Sentinel-3 Altimetry LAND products, ESA is developing dedicated and specialized Level-1 and Level-2 processing chains for all S3 Altimetry Land surfaces, i.e., over Inland Waters and...

Satellite altimeters routinely supply sea surface height (SSH) measurements, which are key observations for monitoring ocean dynamics. However, below a wavelength of about 70 km, along-track altimeter measurements are often characterized by a dramatic drop in signal-to-noise ratio, making it very challenging to fully exploit the available altimeter observations to precisely analyze small mesoscale variations in SSH. Although various approaches have been proposed and applied to identify and filter noise from measurements, no distinct methodology...

Surface oceanic kinetic energy is of interest for many reasons, and a greater understanding of the vertical structure of the kinetic energy would aid interpretation of ongoing and proposed remote sensing missions that are focused on velocity. In this work, kinetic energy (KE) at the sea surface (0 m) and 15 m depth in high-resolution global simulations (HYbrid Coordinate Ocean Model; HYCOM, and Massachusetts Institute of Technology general circulation model; MITgcm) is compared with KE...

The Copernicus Precise Orbit Determination (CPOD) Service delivers, as part of the Ground Segment of the Copernicus Sentinel-1, -2, -3, and -6 missions, orbital products and auxiliary data files for their use in the corresponding Payload Data Ground Segment (PDGS) processing chains at ESA and Eumetsat and to external users through the ESA Copernicus Open Access Hub. In this contribution focus is given to the altimeter satellites Sentinel-3A, -3B, and Sentinel-6 Michael Freilich for which...

Accurate knowledge and understanding of the sea state and its variability is crucial to numerous oceanic and coastal engineering applications. Owing to increased numbers of concurrent satellite missions, both the duration of record and frequency of observations of the sea state have motivated substantial research effort directed at both oceanic and coastal sea state variability. However, owing to a sparsity of high quality in situ long term records, uncertainty in sea state observations remains problematic....

In view of the developing higher spatial resolution altimetry missions, we have been developing new in situ calibration/validation tools. In order to tackle the challenge of higher resolution radar altimeters, their sensitivity to wave or sea surface height heterogeneity within the footprint, we developed instrumentation to investigate more localised and higher frequency SSH signals. The Bass Strait cal/val area is situated in the South West of the strait and is now equipped for the historical...

Inland waters are essential for environmental, societal and economic services such as transport, drinking water, agriculture or power generation. But inland waters are also one of the most affected resources by climate change and human populations growth. Altimetry, which has been used since 1992 for oceanography, has also proven to be a useful tool to estimate inland water surfaces such a rivers and lakes, which are considered Essential Climate Variables (ECVs). the heterogeneity of the...

To keep the reliability of wave parameters from Copernicus Marine Services (CMEMS) at a good level, it is important to update the assimilation system in wave model with new altimeter mission such as Sentinel-6MF (S6MF). This work consists in assessing the impact of using Significant Wave Height (SWH) from S6MF in global and regional operational wave model MFWAM. We implemented long period assimilation experiment of low resolution SWH from S6MF latest level 2 processing for...

Leads between ice floes are key elements to determine the sea surface height in sea ice scenarios since they provide a sea-level reference for the freeboard height measurements. Satellite-based techniques for lead-detection have traditionally required conventional delay-Doppler processing (DDP), where all echoes of a burst are coherently combined within the burst but then incoherently averaged with the other bursts received during the illumination time. DDP has a typical spatial resolution of 300m along-track, which in...

With an along-track resolution of around 300 m, ESA CryoSat-2 (CS2) brought along a whole new range of monitoring possibilities of inland water bodies. The introduction of Synthetic Aperture Radar (SAR) altimetry enabled the study of rivers and lakes that were not visible with conventional Low Resolution Mode (LRM) altimeters. However, the 300 m resolution is still a challenge for the smallest water bodies, for which sometimes none or only a single observation is available....

Satellite radar altimetry is used to observe a wide range of spatial scales, ranging from basin scale to small mesoscale (i.e. less than 100 km). The analysis of the small mesoscale with low-resolution altimetry observations is usually based on along-track products, such as the Geophysical Data Record (GDR). Such product have a resolution as small as 300 m (20-Hz rate), although the resolution most commonly used is 6–7 km (1-Hz rate). Unfortunately, the observation of...

The Haiyang-2B (H2B) mission has been launched in October 2018 by the Chinese Agency NSOAS (National Satellite Ocean Application Service). H2B is the second unit of the Haiyang-2 altimetry Program which also features HY2C (launched in September 2020) and HY2D (launched in May 2021) as well as the upcoming units E to H in the future. These satellites are dedicated to monitor the dynamic ocean environment and they bring a significant contribution to the sampling...

The Copernicus Polar Ice and Snow Topography Altimeter (CRISTAL) mission is planned to be launched in 2027 and will carry the first Ku/Ka band interferometric altimeter (IRIS) for enhanced sea ice thickness measurement and overlying snow depth retrieval. It utilizes a high PRF open burst mode allowing for fully focussed SAR processing with along-track resolutions below 10 m. It will also have the capability to detect icebergs. CRISTAL will also measure ice sheet and glacier...

We describe the latest satellite radar altimeter calibration/validation (CALVAL) results from the Harvest offshore platform and vicinity. Located 10 km off the coast of central California near Point Conception, Harvest has served as the NASA prime verification site for the TOPEX/POSEIDON (T/P) and Jason series of altimeter reference missions for three decades. The T/P repeat ground track was designed to take the satellite directly over Harvest every ten days, enabling the development of a continuous...

AlTiS (Altimetry Time Series) is a software to visualize and process radar altimetry data. It was developed to analyse radar altimetry data over small areas like river, lakes and wetlands, located in the altimetry groundtracks. Its major goal is the creation of time-series of water levels from the height derive from the altimeter measurement but it can also be used to generate time series of any altimetry-based parameters (e.g., corrections applied to the range, backscattering...

Within the OSTST SABIO project, in situ data obtained from CTD (Conductivity, Temperature and Depth) sensors attached on 6 elephant seals (Mirounga Leonina) during the period between the 17th and 31st of October 2019 are analyzed . First, data quality is assessed through the comparison with Satellite Sea Surface Temperature Multi-scale Ultra-high Resolution (SST MUR). The sub-surface (15 m depth) in situ data collected correlates very well (r=0.9) with the SST-MUR, suggesting that the in...

Current operational SSB corrections are derived empirically and built up as look-up tables that describe the SSB amplitude as a 2D function of the SWH and the wind speed parameters, both directly measured by altimeters. Different aspects of the empirical determination have been improved through the years: statistical methods for the SSB modeling, ways to extract the SSB signals from the SSH data, and improvement in the sea state description to better describe in-turn the...

CMEMS Wave TAC next baseline will be 5Hz resolution wave products, 1km along track, to answer to the users community who wants to get closer to the shore. Therefore, in the Sea State community, the literature usually assumes that altimetry waves at 1Hz is dominated by noise (Ardhuin et al. 2019) and most studies tackle this issue by filtering these data up to 50km at least (Quilfen et al. 2018, Dodet et al. 2020). It...

Coastal zones, estuaries and inland waters are among the environments most affected by anthropogenic impact and climate change and are multi-risk due to coastline retreat, flooding and pollution. Accurate knowledge of water height is of major importance to analyze and understand causes and drivers of changes and to plan protection measures. Satellite delay doppler altimetry (DDA) provides improved results compared to conventional altimetry (CA). Goal of this study is the evaluation of the state of...

The FloatEco (Floating Ecosystem) experiment studies physical and biological processes controlling the neopelagic ecosystem emerging in the eastern subtropical North Pacific as a result of marine debris accumulation in the so-called “garbage patch” area. Here, we present preliminary results of the study of pathways of debris into, from, and inside the area based on the analysis of trajectories and derived dynamical characteristics of drifters of various geometry as well as real debris items tagged with...

For the past fifty years, geodetic satellites have contributed to the measurement of numerous geophysical parameters. They thus enabled us to improve our knowledge on several Earth's physical parameters and behaviors, through their refined observation. In particular, the geocentric gravitational coefficient is a key contributor to Satellite Laser Ranging (SLR) validation of the stringent accuracy requirement on the radial positioning of altimeter satellites, defining sea level relative to the Earth’s center of mass. Indeed, SLR...