This presentation is based on the paper by Govoni et al. (2004). We derived Chandra temperature maps for a sample of clusters with high-quality radio halo data, to study the origin of the radio halos. All the sample clusters exhibit distorted X-ray morphology and strong gas temperature variations indicating ongoing mergers. Some clusters, e.g., A520, A665, 1E0657 56, exhibit spatial correlation...

The relationship between urban land surface material fractions (ULSMFs) and brightness temperature has long attracted attention in research on urban environments. In this paper, a multiple endmember spectral mixture analysis (MESMA) method was applied to extract vegetation-impervious surface-soil (V-I-S) fractions in each pixel, and the surface brightness temperature was derived by using the ra...

Brightness temperature difference (BTD) values are calculated for selected Geostationary Operational Environmental Satellite (GOES-6) channels (3.9, 12.7 pm) and Advanced Very High Resolution Radiometer channels (3.7, 12.0 pm). Daytime and nighttime discrimination of particle size information is possible given the infrared cloud extinction optical depth and the BTD value. BTD values are present...

We present a new mathematical technique for retrieving the temperature profile from a ground based microwave profiler and ancillary measurements. It is based on a gradient flow approach. We are able to solve the inverse problem of radiative transfer and determine the temperature profile from ten simultaneous brightness temperature measurements in the range from 50.8 to 58.8 GHz. The approach us...

We review the observations of rapid flux density variations in compact radio sources, and discuss the inverse Compton limit to the maximum brightness temperature of incoherent synchrotron sources in comparison with recent VLBA observations. The apparent agreement of the theoretical brightness temperature limit due to inverse Compton cooling and the brightness temperatures observed by early VLBI...

Context. The inverse Compton catastrophe is the dramatic rise in the luminosity of inverse-Compton scattered photons predicted to occur when the synchrotron brightness temperature exceeds a threshold value, usually estimated to be 1012 K. However, this effect appears to be in contradiction with observation because: (i) the threshold is substantially exceeded by several intra-day variable radio ...

This paper presents a new scheme that classifies convective and stratiform (C/S) precipitation areas over oceans using microwave brightness temperature. In this scheme, data are first screened to eliminate nonraining pixels. For raining pixels, C/S indices are computed from brightness temperatures and their variability for emission (19 and 37 GHz) and scattering (85 GHz). Since lower-resolution...

Nowadays, applications increasingly make use of LEDs as a replacement for traditional light bulbs. For example, LEDs are frequently used in the design of automobile tail lights, signal lights, traffic signals, and variable message signs. LEDs provide several advantages over traditional light bulbs, such as smaller size and longer life. In many applications, the LEDs must be driven with intellig...