High-Spectral- and High-Temporal-Resolution Infrared Measurements from Geostationary Orbit

2009 ◽  
Vol 26 (11) ◽  
pp. 2273-2292 ◽  
Author(s):  
Timothy J. Schmit ◽  
Jun Li ◽  
Steven A. Ackerman ◽  
James J. Gurka
Keyword(s):  
Temporal Resolution ◽  
Spectral Resolution ◽  
Weather Prediction ◽  
Trace Gases ◽  
Geostationary Orbit ◽  
Resolving Power ◽  
High Spectral Resolution ◽  
High Temporal Resolution ◽  
Vertical Resolution ◽  
Infrared Measurements

Abstract The first of the next-generation series of the Geostationary Operational Environmental Satellite (GOES-R) is scheduled for launch in 2015. The new series of GOES will not have an infrared (IR) sounder dedicated to acquiring high-vertical-resolution atmospheric temperature and humidity profiles. High-spectral-resolution sensors have a much greater vertical-resolving power of temperature, moisture, and trace gases than low-spectral-resolution sensors. Because of coarse vertical resolution and limited accuracy in the legacy sounding products from the current GOES sounders, placing a high-spectral-resolution IR sounder with high temporal resolution in the geostationary orbit can provide nearly time-continuous three-dimensional moisture and wind profiles. This would allow substantial improvements in monitoring the mesoscale environment for severe weather forecasting and other applications. Application areas include nowcasting (and short-term forecasts) and numerical weather prediction, which require products such as atmospheric moisture and temperature profiles as well as derived parameters, clear-sky radiances, vertical profiles of atmospheric motion vectors, sea surface temperature, cloud-top properties, and surface properties. Other application areas include trace gases/air quality, dust detection and characterization, climate, and calibration. This paper provides new analysis that further documents the available information regarding the anticipated improvements and their benefits.

scholarly journals Inferring Convective Weather Characteristics with Geostationary High Spectral Resolution IR Window Measurements: A Look into the Future

2009 ◽  
Vol 26 (8) ◽  
pp. 1527-1541 ◽  
Author(s):  
Justin M. Sieglaff ◽  
Timothy J. Schmit ◽  
W. Paul Menzel ◽  
Steven A. Ackerman
Keyword(s):  
Temporal Resolution ◽  
Spectral Resolution ◽  
Atmospheric Stability ◽  
Absorption Lines ◽  
High Spectral Resolution ◽  
High Temporal Resolution ◽  
Tropospheric Temperature ◽  
Carbon Dioxide Absorption ◽  
Water Vapor Absorption ◽  
Infrared Radiances

Abstract A high spectral resolution geostationary sounder can make spectrally detailed measurements of the infrared spectrum at high temporal resolution, which provides unique information about the lower-tropospheric temperature and moisture structure. Within the infrared window region, many spectrally narrow, relatively weak water vapor absorption lines and one carbon dioxide absorption line exist. Frequent measurement of these absorption lines can provide critical information for monitoring the evolution of the lower-tropospheric thermodynamic state. This can improve short-term convective forecasts by monitoring regions of changing atmospheric stability. While providing valuable observations, the current geostationary sounders are spectrally broad and do not resolve the important spectrally narrow absorption lines needed to observe the planetary boundary layer. The usefulness of high spectral resolution measurements from polar-orbiting instruments has been shown in the literature, as has the usefulness of high temporal resolution measurements from geostationary instruments. Little attention has been given to the combination of high temporal along with high spectral resolution measurements. This paper demonstrates the potential utility of high temporal and high spectral resolution infrared radiances.

scholarly journals Added-value of GEO-hyperspectral Infrared Radiances for Local Severe Storm Forecasts Using the Hybrid OSSE Method

2021 ◽  
Author(s):  
Pei Wang ◽  
Zhenglong Li ◽  
Jun Li ◽  
Timothy J. Schmit
Keyword(s):  
Spectral Resolution ◽  
Weather Prediction ◽  
Atmospheric Temperature ◽  
Added Value ◽  
High Spectral Resolution ◽  
Vertical Resolution ◽  
Severe Storm ◽  
Impact Studies ◽  
High Vertical Resolution ◽  
The Impact

AbstractHigh spectral resolution (or hyperspectral) infrared (IR) sounders onboard low earth orbiting satellites provide high vertical resolution atmospheric information for numerical weather prediction (NWP) models. In contrast, imagers on geostationary (GEO) satellites provide high temporal and spatial resolution which are important for monitoring the moisture associated with severe weather systems, such as rapidly developing local severe storms (LSS). A hyperspectral IR sounder onboard a geostationary satellite would provide four-dimensional atmospheric temperature, moisture, and wind profiles that have both high vertical resolution and high temporal/spatial resolutions. In this work, the added-value from a GEO-hyperspectral IR sounder is studied and discussed using a hybrid Observing System Simulation Experiment (OSSE) method. A hybrid OSSE is distinctively different from the traditional OSSE in that, (a) only future sensors are simulated from the nature run and (b) the forecasts can be evaluated using real observations. This avoids simulating the complicated observation characteristics of the current systems (but not the new proposed system) and allows the impact to be assessed against real observations. The Cross-track Infrared Sounder (CrIS) full spectral resolution (FSR) is assumed to be onboard a GEO for the impact studies, and the GEO CrIS radiances are simulated from the ECMWF Reanalysis v5 (ERA5) with the hyperspectral IR all-sky radiative transfer model (HIRTM). The simulated GEO CrIS radiances are validated and the hybrid OSSE system is verified before the impact assessment. Two LSS cases from 2018 and 2019 are selected to evaluate the value-added impacts from the GEO CrIS-FSR data. The impact studies show improved atmospheric temperature, moisture, and precipitation forecasts, along with some improvements in the wind forecasts. An added-value, consisting of an overall 5% Root Mean Square Error (RMSE) reduction, was found when a GEO CrIS-FSR is used in replacement of LEO ones indicating the potential for applications of data from a GEO hyperspectral IR sounder to improve local severe storm forecasts.

Ground-based atmospheric measurements from CHRIS for satellite validation.

2020 ◽  
Author(s):  
El Kattar Marie-Thérèse ◽  
Auriol Frédérique ◽  
Herbin Hervé
Keyword(s):  
Greenhouse Gases ◽  
Spectral Resolution ◽  
Trace Gases ◽  
Space Missions ◽  
High Spectral Resolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Atmospheric Measurements ◽  
Gaseous Species ◽  
Infrared Measurements

<p>Ground-based high spectral resolution infrared measurements are considered to be the most efficient way to obtain accurate tropospheric abundances of different gaseous species and in particular greenhouse gases, such as CO<sub>2</sub> and CH<sub>4</sub>. Furthermore, this type of measurement is also commonly used to validate the satellite retrievals. Despite the outstanding capabilities of the spectrometers used by the TCCON and NDACC networks, they are inadequate for field campaigns; therefore, more compact and stable spectrometers have been developed. <strong>CHRIS</strong> (<strong>C</strong>ompact <strong>H</strong>igh <strong>S</strong>pectral <strong>R</strong>esolution <strong>I</strong>nfrared <strong>S</strong>pectrometer) is a new prototype based on the EM27-SUN from Bruker, with unique characteristics such as its high spectral resolution (0.135 cm<sup>-1</sup> non-apodized) with a spectral sampling every 0.065 cm<sup>-1</sup> to satisfy the Nyquist criterion. This optically stable instrument allows recording solar transmission light spectra in a wide spectral range (680 to 5200 cm<sup>-1</sup>) with a relatively high SNR (~780 in average).</p><p> </p><p>            This instrumental prototype is designed to perform measurements of greenhouse gases (CO<sub>2</sub>, CH<sub>4</sub> and H<sub>2</sub>O), trace gases (SO<sub>2</sub>, CO, HCl, NO<sub>x</sub>…) but also aerosols and clouds that have very typical spectral features in particular in the thermal infrared region. The main objective of this study is the accurate retrieval of tropospheric abundances of the greenhouse gases, CO<sub>2</sub> and CH<sub>4</sub>, in the TIR/SWIR regions, and study the synergy between them especially for the MAGIC campaign. CHRIS is a part of this ongoing campaign in an attempt to monitor the GHG and validate the actual space missions like IASI, OCO-2, GOSAT-2 and future space missions like Merlin, MicroCarb and IASI-NG.</p><p> </p><p>            Here, the spectral and radiometric characterization of this instrument is briefly explained. Furthermore, we present CHRIS’s capabilities to measure CO<sub>2</sub> and CH<sub>4</sub> vertical profiles through a complete information content analysis, a channel selection and an error budget estimation. The preliminary results of the retrieval of these gases using the radiative transfer model ARAHMIS developed at the LOA is also presented. CHRIS is also part of other campaigns such as ImagEtna and Shadow-2 to study the trace gases and aerosols respectively.</p>

scholarly journals A principal component noise filter for high spectral resolution infrared measurements

2004 ◽  
Vol 109 (D23) ◽  
Author(s):  
P. Antonelli ◽  
H. E. Revercomb ◽  
L. A. Sromovsky ◽  
W. L. Smith ◽  
R. O. Knuteson ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Principal Component ◽  
High Spectral Resolution ◽  
Noise Filter ◽  
Infrared Measurements

scholarly journals The impact of GPS and high-resolution radiosonde nudging on the simulation of heavy precipitation during HyMeX IOP6

2021 ◽  
Author(s):  
Alberto Caldas-Alvarez ◽  
Samiro Khodayar ◽  
Peter Knippertz
Keyword(s):  
High Resolution ◽  
Temporal Resolution ◽  
Hydrological Cycle ◽  
Weather Prediction ◽  
Heavy Precipitation ◽  
Convective Precipitation ◽  
Small Scale ◽  
High Temporal Resolution ◽  
The Impact

Abstract. Heavy precipitation is one of the most devastating weather extremes in the western Mediterranean region. Our capacity to prevent negative impacts from such extreme events requires advancements in numerical weather prediction, data assimilation and new observation techniques. In this paper we investigate the impact of two state-of-the-art data sets with very high resolution, Global Positioning System-Zenith Total Delays (GPS-ZTD) with a 10 min temporal resolution and radiosondes with ~700 levels, on the representation of convective precipitation in nudging experiments. Specifically, we investigate whether the high temporal resolution, quality, and coverage of GPS-ZTDs can outweigh their lack of vertical information or if radiosonde profiles are more valuable despite their scarce coverage and low temporal resolution (24 h to 6 h). The study focuses on the Intensive Observation Period 6 (IOP6) of the Hydrological Cycle in the Mediterranean eXperiment (HyMeX; 24 September 2012). This event is selected due to its severity (100 mm/12 h), the availability of observations for nudging and validation, and the large observation impact found in preliminary sensitivity experiments. We systematically compare simulations performed with the COnsortium for Small scale MOdelling (COSMO) model assimilating GPS, high- and low vertical resolution radiosoundings in model resolutions of 7 km, 2.8 km and 500 m. The results show that the additional GPS and radiosonde observations cannot compensate errors in the model dynamics and physics. In this regard the reference COSMO runs have an atmospheric moisture wet bias prior to precipitation onset but a negative bias in rainfall, indicative of deficiencies in the numerics and physics, unable to convert the moisture excess into sufficient precipitation. Nudging GPS and high-resolution soundings corrects atmospheric humidity, but even further reduces total precipitation. This case study also demonstrates the potential impact of individual observations in highly unstable environments. We show that assimilating a low-resolution sounding from Nimes (southern France) while precipitation is taking place induces a 40 % increase in precipitation during the subsequent three hours. This precipitation increase is brought about by the moistening of the 700  hPa level (7.5 g kg−1) upstream of the main precipitating systems, reducing the entrainment of dry air above the boundary layer. The moist layer was missed by GPS observations and high-resolution soundings alike, pointing to the importance of profile information and timing. However, assimilating GPS was beneficial for simulating the temporal evolution of precipitation. Finally, regarding the scale dependency, no resolution is particularly sensitive to a specific observation type, however the 2.8 km run has overall better scores, possibly as this is the optimally tuned operational version of COSMO. In follow-up experiments the Icosahedral Nonhydrostatic Model (ICON) will be investigated for this case study to assert whether its numerical and physics updates, compared to its predecessor COSMO, are able to improve the quality of the simulations.

scholarly journals A Subsystem Test Bed for Chinese Spectral Radioheliograph

2014 ◽  
Vol 31 ◽  
Author(s):  
An Zhao ◽  
Yihua Yan ◽  
Wei Wang
Keyword(s):  
Spectral Resolution ◽  
High Speed ◽  
Digital Signal ◽  
Digital Processing ◽  
Intermediate Frequency ◽  
High Spectral Resolution ◽  
High Temporal Resolution ◽  
Test Bed ◽  
Software Algorithms ◽  
High Speed Data

AbstractThe Chinese Spectral Radioheliograph is a solar dedicated radio interferometric array that will produce high spatial resolution, high temporal resolution, and high spectral resolution images of the Sun simultaneously in decimetre and centimetre wave range. Digital processing of intermediate frequency signal is an important part in a radio telescope. This paper describes a flexible and high-speed digital down conversion system for the CSRH by applying complex mixing, parallel filtering, and extracting algorithms to process IF signal at the time of being designed and incorporates canonic-signed digit coding and bit-plane method to improve program efficiency. The DDC system is intended to be a subsystem test bed for simulation and testing for CSRH. Software algorithms for simulation and hardware language algorithms based on FPGA are written which use less hardware resources and at the same time achieve high performances such as processing high-speed data flow (1 GHz) with 10 MHz spectral resolution. An experiment with the test bed is illustrated by using geostationary satellite data observed on March 20, 2014. Due to the easy alterability of the algorithms on FPGA, the data can be recomputed with different digital signal processing algorithms for selecting optimum algorithm.

scholarly journals Quantifying the Accuracy and Uncertainty of Diurnal Thermodynamic Profiles and Convection Indices Derived from the Atmospheric Emitted Radiance Interferometer

2017 ◽  
Vol 56 (10) ◽  
pp. 2747-2766 ◽  
Author(s):  
W. G. Blumberg ◽  
T. J. Wagner ◽  
D. D. Turner ◽  
J. Correia
Keyword(s):  
Temporal Resolution ◽  
Measurement Errors ◽  
Monte Carlo Sampling ◽  
High Temporal Resolution ◽  
Vertical Resolution ◽  
Moist Convection ◽  
Promising Tool ◽  
Sensing Technology ◽  
Deep Moist Convection ◽  
The Impact

AbstractWhile radiosondes have provided atmospheric scientists an accurate high-vertical-resolution profile of the troposphere for decades, they are unable to provide high-temporal-resolution observations without significant recurring expenses. Remote sensing technology, however, has the ability to monitor the evolution of the atmosphere in unprecedented detail. One particularly promising tool is the Atmospheric Emitted Radiance Interferometer (AERI), a passive ground-based infrared radiometer. Through a physical retrieval, the AERI can retrieve the vertical profile of temperature and humidity at a temporal resolution on the order of minutes. The synthesis of these two instruments may provide an improved diagnosis of the processes occurring in the atmosphere. This study provides a better understanding of the capabilities of the AERI in environments supportive of deep, moist convection. Using 3-hourly radiosonde launches and thermodynamic profiles retrieved from collocated AERIs, this study evaluates the accuracy of AERI-derived profiles over the diurnal cycle by analyzing AERI profiles in both the convective and stable boundary layers. Monte Carlo sampling is used to calculate the distribution of convection indices and compare the impact of measurement errors from each instrument platform on indices. This study indicates that the nonintegrated indices (e.g., lifted index) derived from AERI retrievals are more accurate than integrated indices (e.g., CAPE). While the AERI retrieval’s vertical resolution can inhibit precise diagnoses of capping inversions, the high-temporal-resolution nature of the AERI profiles overall helps in detecting rapid temporal changes in stability.

scholarly journals Instrumental characteristics and Greenhouse gases measurement capabilities of the Compact High-spectral Resolution Infrared Spectrometer: CHRIS

2019 ◽  
Author(s):  
Marie-Thérèse El Kattar ◽  
Frédérique Auriol ◽  
Hervé Herbin
Keyword(s):  
Greenhouse Gases ◽  
Spectral Resolution ◽  
Complete Information ◽  
High Spectral Resolution ◽  
Gaseous Species ◽  
Future Space ◽  
Infrared Measurements ◽  
Thermal Region ◽  
Portable Spectrometers ◽  
Infrared Spectrometer

Abstract. Ground-based high spectral resolution infrared measurements are an efficient way to obtain accurate tropospheric abundances of different gaseous species and in particular GreenHouse Gases (GHG), such as CO2 and CH4. Many ground-based spectrometers are used in the NDACC and TCCON networks to validate the Level 2 satellite data, but their large dimensions and heavy mass makes them inadequate for field campaigns. To overcome these problems, the use of portable spectrometers was recently investigated. In this context, this paper deals with the CHRIS (Compact High-spectral Resolution Infrared Spectrometer) prototype with unique characteristics such as its high spectral resolution (0.135 cm-1 non-apodized) and its wide spectral range (680 to 5200 cm-1). Its main objective is the characterization of gases and aerosols in the infrared thermal region, that's why it requires high radiometric precision and accuracy, which is achieved by performing spectral and radiometric calibrations that will be presented in this paper. Also, CHRIS's capabilities to retrieve CO2 and CH4 vertical profiles are presented through a complete information content analysis, a channel selection and an error budget estimation in the attempt to join the ongoing campaigns, such as MAGIC, to monitor the GHG and validate the actual and future space missions.

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