This study presents a first-of-its-kind comprehensive data fusion approach combining hyperspectral microwave (HMW) with backscatter lidar (BSL) measurements for improved atmospheric thermodynamic sounding, with particular emphasis on the Earth’s Planetary Boundary Layer (PBL). This is a simulation-based trade study to demonstrate the enhancement of HMW over traditional microwave (MW) only measurements and the additional benefits of incorporating BSL with both approaches. This pioneering HMW+BSL fusion methodology represents a major advancement, achieving superior performance compared to traditional thermodynamic remote sensing approaches. Specifically, this configuration demonstrates significant enhancement in PBL temperature bias vertical stability and reduces standard deviation error (SDV) by 30% compared to traditional MW-only performance. Water vapor retrievals show similar improvements, with SDV reductions of 50% in the PBL and bias values consistently maintained below the 10% requirement threshold of the PBL DSI program, compared to PoR errors exceeding 30% bias in challenging cloudy regimes. Case studies across diverse oceanic regions reveal particular advantages of this data fusion approach in complex atmospheric conditions, especially in regions dominated by marine stratocumulus clouds and strong temperature inversions where conventional passive-only retrievals are challenging. Beyond thermodynamic profile improvements, our analysis demonstrates remarkable advances in the detection of PBL height (PBLH), with the HMW+BSL configuration achieving mean absolute errors within the 100 meter requirement threshold of the PBL DSI program, representing a step-change improvement over passive-only approaches. This work directly addresses observational gaps identified in the 2017 Earth Science Decadal Survey, positioning our integrated sensing approach as both a near-term enhancement to existing Earth observation capabilities and a pathfinder for future PBL mission architectures.

We present an overview of the 2024 West-Coast Hyperspectral Microwave Sensor Intensive Experiment (WHyMSIE). WHyMSIE is a joint NASA-NOAA multi-sensor airborne experiment, embracing passive and active sensors from the Program of Record (PoR) along with novel technology funded through the NASA ESTO Instrument Incubation Program. At the core of this effort is the demonstration of the Conical Scanning Millimeter-wave Imaging Radiometer Hyperspectral (CoSMIR-H) instrument, a PBL DSI funded effort to develop hyperspectral sounding capability in the thermal microwave domain finalized to improved temperature and water vapor soundings in the Earth’s Planetary Boundary Layer (PBL). An overview of the field campaign design, instrument payload and validation plan is presented here.

We present a comprehensive Earth Planetary Boundary Layer temperature and water vapor retrieval improvement demonstration by the use of hyperspectral microwave measurements. Our results indicate that the use of a hyperspectral sampling in the oxygen and water vapor sounding lines alone provides significant improvements in the lower and free tropospheric thermodynamic fields (up to 40%), when compared against the program of record (i.e., the Advanced Technology Microwave Sounder, ATMS). Our experiments also demonstrate the essential role played by extending the coverage in the so called spectral window regions, leading to an overall PBL temperature and water vapor improvement of up to 50%.

Characterizing the complex three-dimensional (3D) thermodynamic structure of the Planetary Boundary Layer (PBL) from a global perspective remains a challenge. As identified by the 2017 Decadal Survey and the NASA PBL Incubation Study Team Report (STR), enhanced horizontal and vertical resolution in PBL thermodynamic structure and PBL height from space-based sensors will facilitate major advances in Earth System science across a wide array of disciplines. Current Program of Record (POR) space-borne passive sounders (infrared, microwave) were not designed with a specific PBL focus. Consequently, current operational retrieval methods have limitations that preclude them from profiling PBL temperature and water vapor with the requirements expressed in the NASA PBL Incubation Study Team Report (STR). To that end, the report highlights the need for investing in optimal combinations of different remote sensing approaches and technologies spanning the active and passive field. In this framework, the study lists hyperspectral microwave sensors as an "Essential Component" of the future global PBL observing system, to provide accurate PBL and free tropospheric 3D temperature and water vapor structure context to active measurements (e.g., lidars and radars) and in combination with other passive sensors (e.g., infrared and radio occultation).

We have developed a process for evaluating future satellite-based hyperspectral microwave sensor designs using deep neural networks (DNN). Our approach combines a sophisticated simulated data product with a hierarchical deep neural network capable of comparing the relative performance of a variety of different microwave sounder configurations. These configurations include both spectral band coverage and resolution which allows for a thorough investigation of the solution space. The relative performance between these configurations as tested on the prediction of the planetary boundary layer height (PBLH) is used to perform the evaluation. We plan to extend this method to the prediction of entire temperature and water profiles to further refine this process.

This paper presents an overview of the Hyperspectral Microwave Photonic Instrument (HyMPI), a 2021 NASA Instrument Incubation Proposal funded project aimed at developing the very first hyperspectral microwave sensor to augment thermodynamic sounding capability from space, with a focus on the Earth's Planetary Boundary Layer. This research responds to the recommendation expressed in the 2018 National Academies of Sciences decadal survey to accelerate the readiness of high-priority PBL observables not feasible for cost-effective spaceflight in 2017–2027. This paper provides an overview on HyMPI's design, configured as the objective instrument concept needed to fly in the future PBL mission and presents preliminary trade studies aim at demonstrating HyMPI's enhanced thermodynamic sounding skill in the Earth's Planetary Boundary Layer over conventional microwave sounders from the current Program of Record.

We present an overview of the Hyperspectral Microwave Photonic Instrument (HyMPI), a NASA Instrument Incubation Proposal funded research project aimed at developing a hyperspectral microwave instrument intended for enhanced remote sensing of atmospheric temperature and water vapor from space. This paper provides preliminary results on HyMPI's spectral and noise characteristics and a preliminary demonstration of its enhanced water vapor sensitivity and vertical resolution, with a particular focus on the Earth's Planetary Boundary Layer.

The Joint Polar Satellite System (JPSS) atmospheric composition products are derived from an array of instruments aboard the JPSS satellites, and provide continued support for atmospheric concentrations of both greenhouse gases and aerosols in the context of air quality, furthering scientific understanding, improving environmental monitoring, and enhancing operational applications. This paper presents an outline of the JPSS atmospheric composition products that are operationally available from the JPSS Suomi National Polar-orbiting Partnership (S-NPP) suite of instruments. Experimental products currently under consideration and exploration, continuity and product upgrades for NOAA-20, future plans on collaborations, special data needs by user communities, and upgrades to the data products in support of near real time applications are included in this paper. Continued efforts towards reprocessing to generate mission-long high quality science products, adapting to enterprise algorithms, and providing calibrated radiances and geophysical data products via direct broadcast networks are discussed for user awareness and international collaborations.

This paper provides an overview of the validation of the operational atmospheric vertical temperature profile (AVTP) and atmospheric vertical moisture profile (AVMP) environmental data record (EDR) products retrieved from the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS), two passive sounding systems onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite. The CrIS/ATMS suite serves as the U.S. low earth orbit (LEO) satellite sounding system and will span the future Joint Polar Satellite System (JPSS) LEO satellites. The operational sounding algorithm is the National Oceanic and Atmospheric Administration-Unique Combined Atmospheric Processing System (NUCAPS), a legacy sounder science team algorithm capable of retrieving atmospheric profile EDR products with optimal vertical resolution under nonprecipitating (clear to partly cloudy) conditions. The SNPP NUCAPS AVTP and AVMP EDR products are validated using extensive global in situ baseline data sets, namely, radiosonde observations launched from ground-based networks and ocean-based intensive field campaigns, along with numerical weather prediction model output. Based upon statistical analyses using these data sets, the SNPP AVTP and AVMP EDRs are determined to meet the JPSS Level 1 global performance requirements.

This paper continues an overview of the validation of operational profile retrievals from the Suomi National Polar-Orbiting Partnership (SNPP), with focus here given to the infrared (IR) ozone profile environmental data record (EDR) product. The SNPP IR ozone profile EDR is retrieved using the cross-track IR sounder (CrIS), a Fourier transform spectrometer that measures high-resolution IR earth radiance spectra containing atmospheric state information, namely, vertical profiles of temperature, moisture, and trace gas constituents. The SNPP CrIS serves as the U.S. low earth orbit (LEO) satellite IR sounding system and will be featured on future Joint Polar Satellite System (JPSS) LEO satellites. The operational sounding algorithm is the National Oceanic and Atmospheric Administration-Unique Combined Atmospheric Processing System (NUCAPS), a legacy sounder science team algorithm that retrieves atmospheric profile EDR products, including ozone and carbon trace gases, with optimal vertical resolution under nonprecipitating (clear to partly cloudy) conditions. The NUCAPS ozone profile product is assessed in this paper using extensive global in situ truth data sets, namely, ozonesonde observations launched from ground-based networks and from ocean-based intensive field campaigns, along with numerical weather prediction model output. Based upon rigorous statistical analyses using these data sets, the NUCAPS ozone profile EDRs are determined to meet the JPSS Level 1 global performance requirements.

This work presents an analysis of the vertical resolution of the temperature and water vapor retrieved by the National Oceanic and Atmospheric Administration (NOAA) Unique Combined Atmospheric Processing System (NUCAPS) using averaging kernels as a diagnostic tool. One of the goals of an atmospheric profile retrieval system is to estimate the state of the atmosphere using an optimal set of observations containing independent information content in order to simultaneously minimize the retrieval error and maximize the vertical resolution. The averaging kernels are also used to compute the number of degrees of freedom of retrieved temperature and water vapor in order to estimate the number of useful independent observations contained in the infrared and microwave observations. Our work uses data obtained from the Suomi National Polar-orbiting Partnership (S-NPP) Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) to diagnose the vertical resolution of NUCAPS retrieved sounding products over different latitudes and seasons, and to support comparisons of retrievals against correlative radiosonde measurements. This work is expected to be extended to other NUCAPS products, since the generation of the averaging kernels is a functionality embedded as part of NUCAPS.

NUCAPS (NOAA Unique CrIS/ATMS Processing System) uses the same scientific foundation as AIRS team science algorithm. The NUCAPS is being run operationally at NOAA for Suomi-NPP CrIS/ATMS, Metop-A/B IASI/AMSUA/MHS and provides atmospheric profiles of temperature, moisture, ozone, carbon oxide, carbon monoxide, and Methane. The sounding team at NASA developed a retrieval system using principal component radiative transfer model (PCRTM). The NASA retrieval system can be applied under all weather conditions at single field of view (FOV). In this presentation, we will present the trace gaseous environmental data record from hyperspectral sounders.

We perform a demonstration experiment using the National Oceanic Atmospheric Administration Unique Cross-track Infrared Sounder (CrIS)/Advanced Technology Microwave Sounder Processing System to assess the improvement on trace gas retrievals upon switching to high spectral resolution CrIS radiance measurements (0.625 cm-1). The focus of this study is carbon monoxide retrievals. The experimental high spectral resolution CO retrievals show a remarkable improvement, of almost up to one order of magnitude in the degree of freedom of the signal, with respect to the low-resolution mode. Furthermore, high-resolution CO retrievals show similar skill with respect to existing CO operational products from the Atmospheric InfraRed Sounder, Atmospheric Sounder Interferometer, and Measurements of Pollution In The Troposphere instruments, both in terms of spatial variability and degrees of freedom. The results of this research provide evidence to support the need for high spectral resolution CrIS measurements. This is a fundamental prerequisite in guaranteeing continuity to the CO afternoon orbit monitoring as part of a multisatellite uniformly integrated long-term data record of atmospheric trace gases.

The Cross-track Infrared Sounder (CrIS) was launched on October 28, 2011 aboard the Suomi National Polar-orbiting Partnership platform and is scheduled to become operational in 2012. The purpose of this paper is to describe the National Oceanic and Atmospheric Administration/National Environmental Satellite and Information Service (NOAA/NESDIS) channel selection methodology applied to the CrIS instrument and to present the main spectral characteristics of the final channel subset that will be operationally distributed to the scientific community for near-real-time data assimilation and retrieval applications. We perform an information content analysis and show that this selection, composed of 399 channels, is capable of fully representing the total atmospheric variability contained in the original 1305-channel spectrum, up to instrumental noise. These results ensure that the replacement of the full 1305-channel list in favor of the proposed 399-channel selection will have no detrimental effects on data assimilation and retrieval performance.

Atmospheric Vertical Temperature Profile (AVTP) and Atmospheric Vertical Moisture Profile (AVMP) retrievals produced by the Cross-track Infrared Sounder and the Advanced Technology Microwave Sounder suite (CrIMSS) official algorithm were evaluated with global European Center for Medium Range Weather Forecast (ECMWF) analysis fields, radiosonde (RAOB) measurements, and Aqua-Atmospheric Infrared Sounder (AIRS) heritage algorithm retrievals. The operational CrIMSS AVTP and AVMP product statistics with truth data sets are quite comparable to the AIRS heritage algorithm statistics. Planned updates and improvements to the CrIMSS algorithm will alleviate many issues observed with `day-one' focus-day results and show promise in meeting the Key Performance Parameter (KPP) specifications.

As a part of the Joint Polar Satellite System (JPSS) and the Suomi National Polar-orbiting Partnership (NPP), the Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments make up the Cross-track Infrared and Microwave Sounder Suite (CrIMSS). CrIMSS primarily provides globally-referenced calibrated radiances and vertical profiles of temperature, moisture, and pressure. The CrIMSS operational code has been ported to various LINUX systems and retrievals are performed using both proxy and real ATMS/CrIS data. The high quality proxy data generated from the IASI instrument provided useful testing for the CrIMSS EDR algorithm prior to the launch of the SUOMI NPP satellite. The experience learned from processing the proxy data helped us to handle the SUOMI NPP CrIS/ATMS data as soon as they became available to the CAL/VAL team. In this paper, encouraging preliminary results of applying the ported CrIMSS EDR algorithm to the SUOMI NPP CrIS/ATMS data are presented.

This paper reports on the recent status of the validation program for the Suomi National Polar-orbiting Partnership (NPP) Cross-track Infrared Microwave Sounding Suite (CrIMSS), a hyperspectral infrared sounding system designed for providing high resolution atmospheric vertical temperature and moisture profile (AVTP and AVMP) environmental data records (EDRs). CrIMSS EDR validation activities, currently (as of this writing, May 2012) segueing from the Early-Orbit Checkout (EOC) phase to the Intensive Cal/Val (ICV) phase of the program, are briefly highlighted.

This paper summarizes work investigating the zenith angular dependence of residual cloud and/or aerosol contamination on “clear-sky” infrared observations, which include cloud-cleared radiances and cloud-masked data, along with the implication for achieving agreement with forward calculations over the scanning range of the sensor.

In this letter, we describe a novel implementation scheme for the inversion of the radiative-transfer equation as encountered in satellite remote sensing and incorporatinga prioriinformation. Unlike traditionalmaximum a posterioriapproaches, the new algorithm does not require the use of a forward-model tangent linear and does not pay a large computational time penalty in the use of numerical derivatives. Using spectral data from the European Organisation for the Exploitation of Meteorological Satellites' Infrared Atmospheric Sounding Interferometer sensor, we provide a demonstration of the algorithm and comparison to the National Oceanic and Atmospheric Administration's operationally available product using carbon monoxide as target gas.

Raman Lidar profiles of water vapor and clouds have been coupled with radiosonde measurements of temperature and pressure for use in studying preliminary retrievals from the Aqua satellite as well as raw radiances of the AIRS sensor. Comparisons presented here indicate that the current water vapor retrievals have unresolved biases in the upper troposphere and that calibration differences of 10% and more exist among upper tropospheric measurement systems contributing to uncertainties in the validation of AIRS radiances.