A5026323518- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Calibration and Measurement Techniques
- Meteorological Phenomena and Simulations
- Marine and coastal ecosystems
- Low-power high-performance VLSI design
- Water Quality Monitoring and Analysis
- Oceanographic and Atmospheric Processes
- Advancements in Semiconductor Devices and Circuit Design
- Analog and Mixed-Signal Circuit Design
- Remote Sensing in Agriculture
- Air Quality Monitoring and Forecasting
- Solar Radiation and Photovoltaics
- Semiconductor materials and devices
- Geophysics and Gravity Measurements
- Remote-Sensing Image Classification
- Advanced Memory and Neural Computing
- Geochemistry and Geologic Mapping
- Climate variability and models
- Infrared Target Detection Methodologies
- Quantum-Dot Cellular Automata
- Impact of Light on Environment and Health
- Urban Heat Island Mitigation
Freie Universität Berlin
2008-2021
Colorado State University
2019
Berlin Heart (Germany)
2013
GFZ Helmholtz Centre for Geosciences
2008
Technical University of Munich
2003-2006
Université du littoral côte d'opale
2003
L3S Research Center
1989-1990
Max Planck Society
1990
The development of street lamps based on solid-state lighting technology is likely to introduce a major change in the colour urban skyglow (one form light pollution). We demonstrate need for long-term monitoring this trend by reviewing influences it have disparate fields. describe prototype detector which able monitor these changes, and could be produced at cost low enough allow extremely widespread use. Using detector, we observed differences radiance red, green blue channels. find that...
Abstract. A retrieval of total column water vapour (TCWV) from MODIS (Moderate-resolution Imaging Spectroradiometer) measurements is presented. The algorithm adapted a for MERIS (Medium Resolution Spectrometer) Lindstrot et al. (2012). It obtains the TCWV cloud-free scenes above land at spatial resolution 1 km × and provides uncertainties on pixel-by-pixel basis. has been extended by introducing empirical correction coefficients transmittance calculation within forward operator. With that,...
Abstract. A new scheme for the retrieval of total columnar water vapour from measurements MERIS (Medium Resolution Imaging Spectrometer) on ENVISAT (ENVIronmental SATellite) is presented. The algorithm based a fast forward model transmittance around 900nm, including correction atmospheric scattering and influence temperature- pressure-profile absorption lines. It provides column amount cloud-free scenes above land ocean at spatial resolution 0.25 km × 0.3 1 1.2 km, depending whether applied...
[1] On clear moonlit nights, a band of highly polarized light stretches across the sky at 90 degree angle from moon, and it was recently demonstrated that nocturnal organisms are able to navigate based on it. Urban skyglow is believed be almost unpolarized, therefore expected dilute this unique partially linearly signal. We found urban has greater than linear polarization (p = 8.6 ± 0.3%), confirmed its presence diminishes natural lunar also observed can reduced as moon rises, due...
Abstract. A global time series of total columnar water vapour from combined data the Medium Resolution Imaging Spectrometer (MERIS) onboard ESA's Environmental Satellite (ENVISAT) and Special Sensor Microwave/Imager (SSM/I) satellite US Defense Meteorological Program (DMSP) is presented. The unique set, generated in framework ESA Data User Element (DUE) GlobVapour project, combines atmospheric observations over land ocean, derived measurements near-infrared microwave range, respectively....
Abstract. Hyperspectral radiance measurements in the oxygen A band are sensitive to vertical distribution of atmospheric scatterers, which principle allows retrieval aerosol height from future instruments like TROPOMI, OCO2, FLEX, and CarbonSat. Discussed this paper is a fast flexible forward operator for simulation hyperspectral radiances and, based on scheme, sensitivity study about inversion quality optical thickness, mean height, type. The lookup table with efficient data compression...
Abstract A series of radiative transfer calculations is performed to study the potential using Sun-stimulated chlorophyll fluorescence for detection phytoplankton. Calculated radiance spectra including peak agree well with measurements. We found that natural chlorophyll-a a good predictor phytoplankton, even in waters varying suspended matter and yellow substance concentrations. An increase concentration 1 mg m−3 causes an about 0·05Wm−2sr−1μm−1, when efficiency factor 0·3 per cent was...
This paper will describe the spectral calibration activities conducted during MERIS commissioning phase and operation since orbit 12000. is a medium resolution (300–1200m) push‐broom imaging spectrometer covering domain 390–1040nm with 15 bands, programmable in position width down to steps of 1.25nm. The onboard hardware based on use an Erbium doped‐diffuser panel presenting well‐defined absorption peaks. In mode, configured narrow bands centred feature (two are used). first orbit,...
Abstract This paper presents first validation results for an algorithm developed the retrieval of integrated columnar water vapor from measurements Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on board polar-orbiting Terra and Aqua platforms. The is based absorption reflected solar radiation by atmospheric allows above cloud-free land surfaces. A comparison retrieved with Microwave Water Radiometer at Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP)...
Fine-grained sleep transistor circuits are demonstrated with 0.12μm 16 b MAC (multiply-accumulate unit). Standby power is reduced by a factor of 5500 at 85°C speed reduction 5%. Charge recycling reduces the minimum time 25%. Dynamic dissipation decreases 16% activating fraction switch in slow mode. Double switching inhibits power-on glitches and current spikes 38%.
Abstract. A broad range of different Bayesian cloud detection schemes is applied to measurements from the Medium Resolution Imaging Spectrometer (MERIS), Advanced Along-Track Scanning Radiometer (AATSR), and their combination. The were designed be numerically efficient suited for processing large numbers data. Results classical naive approach masking are discussed MERIS AATSR as well sensitivity study on resolution multidimensional histograms, which post-processed by Gaussian smoothing,...
The "differential absorption technique" is used to derive columnar water vapor contents above clouds. Radiative transfer simulations were carried out for two different spectral channels, one channel within the ρστ–water band and window channel. performed instruments, ENVISAT's Medium Resolution Imaging Spectrometer (MERIS) Polarization Directionality of Earth Reflectances (POLDER) instrument on ADEOS platform. Vertical weighting functions contribution cloud layers total by have been...
Abstract. Positive Feedback Adiabatic Logic (PFAL) shows the lowest energy dissipation among adiabatic logic families based on cross-coupled transistors, due to reduction of both and non-adiabatic losses. The primarily depends resistance charging path, which consists a single p-channel MOSFET during recovery phase. In this paper, new family called Improved PFAL (IPFAL) is proposed, where all n- pchannel devices are swapped so that charge can be recovered through an n-channel MOSFET. This...
Backscattered solar radiation as measured by MOS (Modular Optoelectronical Scanner) on the IRS3 (Indian Remote sensing Satellite 3) has been used in an algorithm to retrieve cloud top pressure. The uses a radiance ratio between absorbing channels Oxygen‐A absorption band at 761 nm and window channel 750 nm. ratios are directly related average photon path length, which is mainly determined This paper presents principles of retrieval scheme, results sensitivity study first validation using radiosondes.
A new method to retrieve cloud top heights stereoscopically using the dual‐view facility of Along Track Scanning Radiometer 2 (ATSR‐2) instrument is assessed. This assessment performed through a comparison obtained from ATSR‐2 stereo and those derived 94‐GHz radar, radiosonde profiles independently Modular Optoelectronic Scanner (MOS) O2‐A band. The data for this study were collected over United Kingdom September 1998–March 1999. results show that accuracy generally as predicted on...
Tropospheric water vapor delay is the main error source limiting accuracy of SAR interferometric measurements. In Persistent Scatterer Interferometry (PSI), presence atmospheric effects increases required data amount for PSI immensely, reaction time and applicability technique. On ENVISAT, products derived from optical sensor MERIS may be used to mitigate tropospheric in simultaneously acquired ASAR data. this paper signals are compared, methods their optimal combination suggested.
Abstract. A newly developed daytime cloud property retrieval algorithm, FAME-C (Freie Universität Berlin AATSR MERIS Cloud), is presented. Synergistic observations from the Advanced Along-Track Scanning Radiometer (AATSR) and Medium Resolution Imaging Spectrometer (MERIS), both mounted on polar-orbiting Environmental Satellite (Envisat), are used for screening. For cloudy pixels two main steps carried out in a sequential form. First, optical microphysical performed using an near-infrared...
Due to the noise that is present in remote sensing data, a robust method retrieve information needed. In this study, active learning (ALM) applied spectral reflectance data in‐water pigment. The heart of ALM fuzzy interpolation called ink drop spread (IDS). Three datasets (SeaBAM, synthetic and NOMAD) are used for evaluation selected approach. Comparison with ocean colour 4 (OC4) algorithm artificial neural network (ANN) demonstrated robustness approach retrieval constituents from data....
This paper discusses results from 12 months of a Round Robin exercise aimed at the inter-comparison different cloud detection algorithms for Proba-V. Clouds is critical issue satellite optical remote sensing, since potential errors in masking directly translates into significant uncertainty retrieved downstream geophysical products. Cloud particularly challenging Proba-V due to presence limited number spectral bands and lack thermal infrared bands. The main objective project was several over...
Abstract. A new scheme for the retrieval of total columnar water vapour from measurements MERIS (Medium Resolution Imaging Spectrometer) on ENVISAT (ENVIronmental SATellite) is presented. The algorithm based a fast forward model transmittance around 900 nm, including correction atmospheric scattering. It provides column amount cloud-free scenes above land and ocean at spatial resolution 0.25 km × 0.3 1 1.2 km, depending whether applied to "full resolution" or operational "reduced mode MERIS....
An adiabatic 8-bit ripple carry adder is realized in a 1.2V, 0.13/spl mu/m CMOS technology, to demonstrate the potential of logic for low power applications. The layout back compatible with static standard cells. This enables implementation large circuit blocks manageable design complexity. At f=20 MHz, energy by factor 7 lower than CMOS, and saving achievable beyond f=100MHz. Interface circuits are presented conversion between environment. efficiency complete system evaluated including...
Abstract. A retrieval of total column water vapour (TCWV) from MODIS (Moderate-resolution Imaging Spectroradiometer) measurements is presented. The algorithm adapted a for MERIS (Medium Resolution Spectrometer) Lindstrot et al. (2012). It obtains the TCWV cloud-free scenes above land at spatial resolution 1 km × and provides uncertainties on pixel-by-pixel basis. has been extended by introducing correction coefficients transmittance calculation within forward operator. With that wet bias...
Abstract. This study presents a quantification of uncertainties total column water vapour retrievals based on simulated near-infrared measurements upcoming instruments. The concepts three scheduled spectrometers were taken into account: OLCI (Ocean and Land Color Instrument) Sentinel-3, METimage an EPS-SG (EUMETSAT Polar System – Second Generation) satellite FCI (Flexible Combined Imager) MTG (Meteosat Third Generation). Optimal estimation theory was used to estimate the error hypothetical...
Abstract Top-of-atmosphere (TOA) shortwave (SW) angular distribution models (ADMs) approximate—per direction of an imagined upward hemisphere—the intensity sunlight scattered back from a specific Earth–atmosphere scene. ADMs are, thus, critical when converting satellite-borne broadband radiometry into estimated radiative fluxes. This paper applies set newly developed with more refined scene definition and demonstrates tenable changes in fluxes compared to currently operational ADMs. Newly...