Radar Altimeter Measurements Research Articles

Performance of ERA5 wind speed and significant wave height within Extratropical cyclones using collocated satellite radar altimeter measurements

ABSTRACT Similar in strength to hurricanes, Extratropical Cyclones (ECs) are responsible for innavigable sea states, coastal inundation and erosion, and subsequent destruction to coastal infrastructure. Across modern operational wave models, there exists a known systematic underestimation of wave heights during these extreme events. Using a global database of EC storm tracks and 36 years of satellite altimeter data, we examine EC structure and assess model performance through storm centered composite analyses of significant wave height ( H s ) and U10 wind speed ( | U 10 | ). Through the collocation of satellite altimeter observations with a state-of-the-art reanalysis product (ERA5), we investigate model performance with respect to | U 10 | and H s within ECs of varying intensities. By rotating our data reference frames, we align all storm directions to account for asymmetry in EC wind fields and subsequent increased wave growth This rotation results in the organization of the strongest wind speed and H s , as well as trends in the ERA5 performance. A characteristic EC radii is calculated and used to normalize data coordinates in the storm centered reference frame, which highlights the organization of EC structures. Performance metrics are then compared within different EC quadrants to explore the relationship between wind forcing accuracy and underestimation of H s .

Comparing elevation and backscatter retrievals from CryoSat-2 and ICESat-2 over Arctic summer sea ice

Abstract. The CryoSat-2 radar altimeter and ICESat-2 laser altimeter can provide complementary measurements of the freeboard and thickness of Arctic sea ice. However, both sensors face significant challenges for accurately measuring the ice freeboard when the sea ice is melting in summer months. Here, we used crossover points between CryoSat-2 and ICESat-2 to compare elevation retrievals over summer sea ice between 2018–2021. We focused on the electromagnetic (EM) bias documented in CryoSat-2 measurements, associated with surface melt ponds over summer sea ice which cause the radar altimeter to underestimate elevation. The laser altimeter of ICESat-2 is not susceptible to this bias but has other biases associated with melt ponds. So, we compared the elevation difference and reflectance statistics between the two satellites. We found that CryoSat-2 underestimated elevation compared to ICESat-2 by a median difference of 2.4 cm and by a median absolute deviation of 5.3 cm, while the differences between individual ICESat-2 beams and CryoSat-2 ranged between 1–3.5 cm. Spatial and temporal patterns of the bias were compared to surface roughness information derived from the ICESat-2 elevation data, the ICESat-2 photon rate (surface reflectivity), the CryoSat-2 backscatter, and the melt pond fraction derived from Sentinel-3 Ocean and Land Color Instrument (OLCI) data. We found good agreement between theoretical predictions of the CryoSat-2 EM melt pond bias and our new observations; however, at typical roughness <0.1 m the experimentally measured bias was larger (5–10 cm) compared to biases resulting from the theoretical simulations (0–5 cm). This intercomparison will be valuable for interpreting and improving the summer sea ice freeboard retrievals from both altimeters.

The Terprom® Digital Terrain System (DTS)

Developed specifically for tactical military aircraft operations, TERPROM® is the world leading Digital Terrain System, offering a range of capabilities that can provide both safety and tactical benefits to the aircraft. The system is an established and well-proven product that has been in production since 1991. To date it has been selected by fourteen Nations worldwide for use on numerous platforms. The number of military aircraft equipped with TERPROM® is now over 5000 and growing. TERPROM® provides the following functions: Terrain Referenced Navigation (TRN), Predictive Ground Collision Avoidance System (PGCAS), Advanced Terrain Avoidance Cueing (ATAC), Obstruction and Wires Warning and Cueing (OWWC), Database Terrain Following (DBTF), Air to Ground Ranging Functions, Terrain Awareness Display (TAD). At the core of the system is the Terrain Referenced Navigation (TRN) capability which navigates by combining aircraft navigation data (e.g. inertial and, or GPS) and radar altimeter measurements of height above ground level (AGI), with terrain heights alms from the stored map data, to produce a navigation solution referenced to the terrain map data. This navigation solution then allows the other TERPROM® functions to use the map data to provide their safety and tactical capabilities. Three variants of TERPROM® have been developed to satisfy the airborne platform market: - Fast Jet, Military Transport, Helicopter. TERPROM® is a living product that has and continues to receive significant internal investment to increase its capability, functionality and performance to support future opportunities. Current areas of development include: Use of higher resolution map data which will increase the performance of TERPROM® and offer enhanced capability to platforms flying nap of the earth, enhanced capability in urban areas and could also reduce any platform reliance on GPS. Integration with active forward looking sensors to provide additional information to the Navigation, Situational Awareness and Ranging functions and also to provide new capabilities such as real time mapping of unmapped terrain features and obstructions.

Estimation of Lake Ice Thickness with Satellite Radar Altimeter Waveforms

Background and Relevance: The phenology of seasonally ice covered lakes has been altered with anthropogenic climate change; recent studies point out an overall reduction in the number of days in which the lake is covered with ice [1]. Lake ice is essential for many northern communities in fishing and travel. Reductions in the thickness in ice is a major safety risk, especially when those who travel on ice have historically been able to trust it. Remote sensing efforts have majorly focused on sea ice and glacial changes, and little is known about changes in lake ice thickness besides the seasonal length of ice coverage. Previous researchers have determined that the Ku-band (13 to 17 GHz) is capable of penetrating through freshwater ice and is scattered from both the snow/ice and the ice/water interfaces [1]. A radar altimeter operating at the Ku-band holds the potential to measure the height of the sensor above the snow/ice interface and above the ice/water interface. The difference between these two measurements yields the ice thickness. This method has been confirmed with data from the Cryosat-2 satellite [1], but only tested with arctic lakes. There is a gap in knowledge of how midlatitude lakes have responded to changing climates in terms of their seasonal ice thickness. Objectives and Methods: Ku-band radar altimeter measurements from the JASON series of satellites can be used to determine lake ice thickness by calculating the distance between dualpeak waveforms, representative of snow/ice and ice/water interfaces. A study area will be chosen after a review of the available data coverage and an overall analysis of scattering. Snowpack, bubbles, and wetness of the ice adds noise to the waveform and complicates the ice thickness retrieval. A lake that minimizes these factors will be selected for the study area. Data will be extracted from an orbit passing over the lake for each month of a year and in intervals of 5 years. The JASON series has the following advantages to the Cryosat-2 satellite: Improved temporal resolution – CryoSat-2 covers polar regions, while the JASON Series covers the area between N: 66.15° N and S: -66.15°; and greater coverage – Jason-1/2/3 have the shortest revisit cycle (~10 days) among all existing satellite altimeters and have been operating since 1992 [2]. The radar altimeter measurements will be displayed as the travel distance as a function of mean normalized power. The difference between peaks on the waveform will be calculated and logged as the ice thickness during that time. The results will be validated by comparing the estimated lake ice thickness values with ice fishing logs from similar dates. There is potential for the ice thickness data to be interpolated across the entirety of the lake using ArcGIS Pro, but this is contingence on the specifics of the study area. Anticipated Contributions: This study will: (1) estimate ice thickness in areas where in situ drillhole measurements cannot be taken, (2) introduce another factor in climate change discussions and models, (3) further our ability to monitor biophysical factors with remote sensing at global scales. [1] J. F. Beckers, J. Alec Casey and C. Haas, "Retrievals of Lake Ice Thickness From Great Slave Lake and Great Bear Lake Using CryoSat-2," in IEEE Transactions on Geoscience and Remote Sensing, vol. 55, no. 7, pp. 3708-3720, July 2017, doi: 10.1109/TGRS.2017.2677583. [2] C. J. Donlon et al., “The Copernicus Sentinel-6 mission: Enhanced continuity of satellite sea level measurements from space,” Remote sensing of environment, vol. 258, p. 112395–, 2021, doi: 10.1016/j.rse.2021.112395.

Variability of surface gravity wave field over a realistic cyclonic eddy

Abstract. Recent remote sensing measurements and numerical studies have shown that surface gravity waves interact strongly with small-scale open ocean currents. Through these interactions, the significant wave height, the wave frequency, and the wave direction are modified. In the present paper, we investigate the interactions of surface gravity waves with a large and isolated realistic cyclonic eddy. This eddy is subject to instabilities, leading to the generation of specific features at both the mesoscale and submesoscale ranges. We use the WAVEWATCH III numerical framework to force surface gravity waves in the eddy before and after its destabilization. In the wave simulations the source terms are deactivated, and waves are initialized with different wave intrinsic frequencies. The study of these simulations illustrates how waves respond to the numerous kinds of instabilities in the large cyclonic eddy from a few hundred to a few tens of kilometres. Our findings show that the spatial variability of the wave direction, the mean period, and the significant wave height is very sensitive to the presence of submesoscale structures resulting from the eddy destabilization. The intrinsic frequency of the incident waves is key in the change of the wave direction resulting from the current-induced refraction and in the location, from the boundary where waves are generated, of the maximum values of significant wave height. However, for a given current forcing, the maximum values of the significant wave height are similar regardless of the frequency of the incident waves. In this idealized study it has been shown that the spatial gradients of wave parameters are sharper for simulations forced with the destabilized eddy. Because the signature of currents on waves encodes important information of currents, our findings suggest that the vertical vorticity of the current could be statistically estimated from the significant wave height gradients down to a very fine spatial scale. Furthermore, this paper shows the necessity to include currents in parametric models of sea-state bias; using a coarse-resolution eddy field may severely underestimate the sea-state-induced noise in radar altimeter measurements.

The Copernicus Sentinel-6 mission: Enhanced continuity of satellite sea level measurements from space

Given the considerable range of applications within the European Union Copernicus system, sustained satellite altimetry missions are required to address operational, science and societal needs. This article describes the Copernicus Sentinel-6 mission that is designed to provide precision sea level, sea surface height, significant wave height, inland water heights and other products tailored to operational services in the ocean, climate, atmospheric and land Copernicus Services. Sentinel-6 provides enhanced continuity to the very stable time series of mean sea level measurements and ocean sea state started in 1992 by the TOPEX/Poseidon mission and follow-on Jason-1, Jason-2 and Jason-3 satellite missions. The mission is implemented through a unique international partnership with contributions from NASA, NOAA, ESA, EUMETSAT, and the European Union (EU). It includes two satellites that will fly sequentially (separated in time by 5 years). The first satellite, named Sentinel-6 Michael Freilich, launched from Vandenburg Air Force Base, USA on 21st November 2020. The satellite and payload elements are explained including required performance and their operation. The main payload is the Poseidon-4 dual frequency (C/Ku-band) nadir-pointing radar altimeter that uses an innovative interleaved mode. This enables radar data processing on two parallel chains the first provides synthetic aperture radar (SAR) processing in Ku-band to improve the received altimeter echoes through better along-track sampling and reduced measurement noise; the second provides a Low Resolution Mode that is fully backward-compatible with the historical reference altimetry measurements, allowing a complete inter-calibration between the state-of-the-art data and the historical record. A three-channel Advanced Microwave Radiometer for Climate (AMRC) provides measurements of atmospheric water vapour to mitigate degradation of the radar altimeter measurements. The main data products are explained and preliminary in-orbit Poseidon-4 altimeter data performance data are presented that demonstrate the altimeter to be performing within expectations.

Monthly Surface Elevation Changes of the Greenland Ice Sheet From ICESat-1, CryoSat-2, and ICESat-2 Altimetry Missions

The Greenland Ice Sheet (GrIS) mass balance shows significant variabilities over a range of time scales. As geodetic records lengthen over time, it becomes insufficient to characterize the temporal evolution of the ice sheet by using a best-fit linear trend over a given observation period. This study investigates the joint analysis of laser and radar satellite altimeter measurements for estimating GrIS surface elevation changes (SECs) with a 30-day resolution. We first apply a crossover analysis to assess the precisions of the surface elevations measured by ICESat-1/2 laser altimeters and CryoSat-2 radar altimeter over the GrIS, which are needed for assigning weights for each data set in the joint analysis. Then, based on a modified repeat-track approach, we analyze the surface elevation measurements of ICESat-1/2 and CryoSat-2 to produce monthly SEC estimates for the past two decades, together with their associated uncertainties. The multimission SEC estimates are further assessed by using IceBridge airborne laser measurements, showing differences with a median value of −12 cm ± 60 cm. The monthly SEC time series reveal important variations over a range of time scales across different parts of the GrIS and would facilitate the investigation of complex spatiotemporal patterns of GrIS changes.

Trace-Norm Regularized Multi-Task Learning for Sea State Bias Estimation

Sea state bias (SSB) is an important component of errors for the radar altimeter measurements of sea surface height (SSH). However, existing SSB estimation methods are almost all based on single-task learning (STL), where one model is built on the data from only one radar altimeter. In this paper, taking account of the data from multiple radar altimeters available, we introduced a multi-task learning method, called trace-norm regularized multi-task learning (TNR-MTL), for SSB estimation. Corresponding to each individual task, TNR-MLT involves only three parameters. Hence, it is easy to implement. More importantly, the convergence of TNR-MLT is theoretically guaranteed. Compared with the commonly used STL models, TNR-MTL can effectively utilize the shared information between data from multiple altimeters. During the training of TNR-MTL, we used the JASON-2 and JASON-3 cycle data to solve two correlated SSB estimation tasks. Then the optimal model was selected to estimate SSB on the JASON-2 and the HY-2 70–71 cycle intersection data. For the JSAON-2 cycle intersection data, the corrected variance (M) has been reduced by 0.60 cm2 compared to the geophysical data records (GDR); while for the HY-2 cycle intersection data, M has been reduced by 1.30 cm2 compared to GDR. Therefore, TNR-MTL is proved to be effective for the SSB estimation tasks.

DESCENT TRAJECTORY MODELLING FOR THE LANDING SYSTEM PROTOTYPE

This paper gives another view on a method used for aircraft approach and landing phase of flight that enables replacement of standard glideslope. Proposed Landing System is based on Terrain Reference Navigation (TRN) using own created terrain elevation database, based on Radar Altimeter (RA) measurements compared to the overflown terrain. Simulations were performed on a chosen airport (KSC – Košice Airport) and aircraft (Boeing 737-800), where descend procedures was designed based on real airline data in compliance with Initial 4D Trajectory (i4D). Descend trajectory was modelled with EUROCONTROL Base of Aircraft DAta (BADA) performance model as a Continuous Descent Approach (CDA) from proposed merging point to the KSC RunWaY (RWY) threshold. This method was proposed to enhance pilot situational awareness in situations when standard Instrument Landing System (ILS) information could be lost or misleading and without the need of any ground station for successful navigation and guidance to the RWY threshold. Landing System prototype flight test were performed on full mission flight simulator.

Niger discharge from radar altimetry: bridging gaps between gauge and altimetry time series

Abstract. The Niger River represents a challenging target for deriving discharge from spaceborne radar altimeter measurements, particularly since most terrestrial gauges ceased to provide data during the 2000s. Here, we propose deriving altimetric rating curves by “bridging” gaps between time series from gauge and altimeter measurements using hydrological model simulations. We show that classical pulse-limited altimetry (Jason-1 and Jason-2, Envisat, and SARAL/Altika) subsequently reproduces discharge well and enables continuing the gauge time series, albeit at a lower temporal resolution. Also, synthetic aperture radar (SAR) altimetry picks up the signal measured by earlier altimeters quite well and allows the building of extended time series of higher quality. However, radar retracking is necessary for pulse-limited altimetry and needs to be further investigated for SAR. Moreover, forcing data for calibrating and running the hydrological models must be chosen carefully. Furthermore, stage–discharge relations must be fitted empirically and may need to allow for break points.

Application of different wind field models and wave boundary layer model to typhoon waves numerical simulation in WAVEWATCH III model

Taking severe typhoon Kalmaegi (2014) as an example, which is chosen due to its good availability of observations from mulitplatforms, the application ability of different wind field models and wave boundary layer model (WBLM) are investigated simultaneously in WAVEWATCH III model (WW3). First, based on the comparisons between measurements of two in situ buoys and model results, a better-quality wind forcing from WRF’s output stands out slightly compared with other two constructed wind fields during the time segment of “During-TY”. Second, the comparisons of simulated results by using different drag coefficient schemes between WBLM and the original parameterisation formula in ST2 package are further implemented. The good performance of drag coefficient from WBLM under high-wind conditions, which is embedded into ST2 wind-input source function, is also verified by several data set of field observations. As a result, on the basis of the observations from buoy-based and radar altimeter measurements (RAs), the values of significant wave height () from simulation with WBLM are weaker at high sea state areas () compared with that from the ST2 scheme, which coincide with the general knowledge that the amount of momentum exchange at the air-sea interface plays a vital role in the development of typhoon waves. Limited by less frequently sampled collocated measurements under high-wind conditions, the effectiveness of improvement for typhoon waves simulation using WBLM in WW3 requires more validation cases in future work.

Reflectance reference target at Järvselja, Estonia for the calibration of optical remote sensing sensors and lessons learned

A calibration target for the support of airborne and satellite measurements was built at the Järvselja site for ecological and remote sensing studies located in southeastern Estonia. The calibration target is a 10 × 10 m concrete panel which is protected by a removable roof. Optical properties of the panel are carefully studied in order to serve as a reference in spectroscopic remote sensing measurements. In this study we report the spectral distribution of reflectance in the wavelength range of 350–2500 nm, the angular distribution of directional reflectance and the linear polarization of the reflected radiation. The reflectance spectrum of the panel is smooth in the visible and NIR wavelengths but with steep decrease at wavelengths less than 400 nm. Variations of reflectance over the panel surface are less than 1%. The radiation is partly polarized in forward scattering direction. No temporal changes of optical properties have been observed. The calibration target improves the metrological quality of airborne spectral measurements at the Järvselja test site and neighboring areas. It can also be used for ground truth to aid the validation of adjacency correction algorithms for data from high spatial resolution satellite images, as well as a reference for the registration of airborne and satellite images. It can also serve as an elevation reference for both lidar and radar altimeter measurements.

Corrections to “Fine-Resolution Radar Altimeter Measurements on Land and Sea Ice” [May 15 2547-2564

In the above paper [1] , there is an error in Table I . The value “30” in the bottom row, fifth column should be “350.” The corrected table is provided here.

Research on the Method of Re-construct Satellite Radar Altimeter Measurements Datum over Coastal Waters based on Transponder

Research on the Method of Re-construct Satellite Radar Altimeter Measurements Datum over Coastal Waters based on Transponder

A mixture regularized rao-blackwellized particle filter for terrain positioning

This study is concerned with the development of a robust particle filtering algorithm tailored to the problem of terrain-aided positioning (TAP) via radar altimeter measurements. The Rao-Blackwellized particle filter (RBPF) is a popular particle filtering algorithm for TAP that takes advantage of the nature of the state-space model by sampling particles in a subspace of the state space, yielding more efficient estimators than the standard particle filter. Like most Monte Carlo filters, the standard RBPF uses the transition kernel as the proposal distribution during the particle update step. However, in contexts where the likelihood function is peaky, this may be highly inefficient since samples may fall in regions of low posterior probability. To address this issue, it is often advocated to use an importance sampling density that takes into account the latest observation. In a sequential importance sampling context, an optimal importance density is available but can be easily sampled only for specific state-space models, which raises the question of how to design a proposal density that is efficient yet easy to sample from. In this paper, we propose a particle filtering importance sampling method adapted to multimodal distributions. It hinges on the use of a robust proposal density as well as a cluster-based representation of the multimodal posterior. This leads to a novel marginalized particle filter, the regularized RBPF, that is evaluated on a challenging terrain positioning application.

Sea Surface Reflectivity Variation With Ocean Temperature at Ka-Band Observed Using Near-Nadir Satellite Radar Data

Satellite ocean radar data are used to assess the flat surface reflectivity for seawater at 36 GHz by comparison to an existing model for dielectric constant variation. Sea surface temperature (SST) is the dominant control, and results indicate a 14% variation in the normalized radar cross section (NRCS) at Ka-band (35.75 GHz) that is in close agreement with model prediction. Consistent results are obtained globally using near-nadir incidence data from both the SARAL AltiKa radar altimeter and Global Precipitation Measurement mission rain radar. The observations affirm that small but systematic SST-dependent corrections at Ka-band may require consideration prior to NRCS use in ocean surface wave investigations and applications. As an example, we demonstrate a systematic improvement in AltiKa ocean wind speed inversions after such an SST adjustment. Lower frequency C- and Ku-band results are also assessed to confirm the general agreement with prediction and a much smaller variation due to SST.

Calibration of HY-2A satellite significant wave heights with in situ observation

Significant wave height (SWH) can be computed from the returning waveform of radar altimeter, this parameter is only raw estimates if it does not calibrate. But accurate calibration is important for all applications, especially for climate studies. HY-2a altimeter has been operational since April 2012 and its products are available to the scientific community. In this work, SWH data from HY-2A altimeters are calibrated against in situ buoy data from the National Data Buoy Center (NDBC), Distinguished from previous calibration studies which generally regarded buoy data as “truth”, the work of calibration for HY-2A altimeter wave data against in situ buoys was applied a more sophisticated statistical technique—the total least squares (TLS) method which can take into account errors in both variables. We present calibration results for HY-2A radar altimeter measurement of wave height against NDBC buoys. In addition, cross-calibration for HY-2A and Jason-2 wave data are talked over and the result is given.

Fine-Resolution Radar Altimeter Measurements on Land and Sea Ice

Satellite radar altimeter (RA) measurements are important for continued monitoring of rapidly changing polar regions. In 2010, the European Space Agency launched CryoSat-2 carrying SIRAL, a Ku-band RA with objectives of determining the thickness and extent of sea ice and the topography of the ice sheets. One difficulty with Ku-band radar surveys over snow and ice is unknown penetration of RA signal into snow cover. Improving our understanding of the interactions of RA signals with snow and ice is needed to produce accurate elevation products. To this end, we developed a low-power, ultrawideband (12-18 GHz) RA for airborne surveys to provide fine resolution measurements capable of detecting both scattering from the surface and layers within sea ice and ice sheets. These measurements provide a means of identifying the dominant scattering location of lower resolution RA measurements comparable to satellite-based instruments. We generated two products: a full-bandwidth waveform (FBW) to identify scattering targets at fine resolution and a reduced-bandwidth waveform (RBW) to represent conventional RA measurements. Retrackers are used to generate height estimates over various surface conditions for comparisons. Over ice sheets, the leading-edge tracker provided consistent ice-surface elevation measurements between the FBW and RBW results; however, there were significant differences between the results from the centroid tracker. Over sea ice, the location of the dominant return between the results from snow-covered sea ice is highly variable. This paper provides an overview of RA surveys in polar regions, a description of the CReSIS system, and a discussion of the results.

Spatial Coherence of winds and waves over the Arabian Sea and Bay of Bengal and their evolution during SW Monsoon: a novel application of along-track Radar Altimeter measurements from Space

Abstract. We have examined, for the first time, the spatial coherence of oceanic parameters, namely, the ocean surface wind and significant wave height (SWH), using near-instantaneous along-track sampling over vast oceanic tracks provided by Poseidon-2 Radar Altimeter onboard Jason-1. The spatial coherence length scales over the Arabian Sea and the Bay of Bengal regions, derived using Auto correlation analysis, display interesting characteristics in relation to onset and evolution of SW Monsoon over India. The estimated spatial coherence scales are found to be of the order of 100–500 km. Generally, SWH coherence lengths over Arabian Sea are observed to increase from June to July during good monsoon year (2012). This trend is not followed for the poor monsoon year (2002). Similar trend is observed for spatial coherence scales for wind speed. The temporal evolution of analyzed spatial coherence scales of winds and waves over Arabian Sea clearly brings out the distinction between a "good" (2012) and a "poor" (2002) monsoon year. The spatial coherence lengths of these parameters over the Bay of Bengal are found to be shorter and do not show any systematic relation to onset and evolution of SW monsoon. Anisotropy in coherence lengths is also analyzed by treating ascending and descending tracks separately. Generally, the descending tracks measurements show higher spatial coherence lengths than the ascending ones. Like the spatial coherence scales, the anisotropy of the coherence scales over the Arabian Sea also mimics the behaviour of the strength of SW Monsoon.

Statistical Entry, Descent, and Landing Performance Reconstruction of the Mars Science Laboratory

The Mars Science Laboratory spacecraft landed an approximately 900 kg rover on Mars on 5 August 2012. Similar to past Mars missions, the spacecraft recorded inertial measurement unit data and radar altimeter measurements, but its aeroshell was also instrumented with flush atmospheric data system sensors that captured the pressure distribution on the vehicle during hypersonic and supersonic flight regimes. The rich data set enables a comprehensive postflight analysis of the vehicle’s trajectory, atmosphere, and aerodynamics. This paper demonstrates a comprehensive statistical estimation methodology and applies it to the large but disparate data set to reconstruct the vehicle’s entry performance, while using several statistical estimation methods, specifically the extended Kalman filter, unscented Kalman filter, and adaptive filter, which concurrently estimate both the state and the uncertainties. The results of the analysis shows good agreement between the estimated states, preflight predictions, and independent reconstructions, while also demonstrating the efficacy of the comprehensive statistical estimation method for Mars entry, descent, and landing reconstruction.