We demonstrate a polarization-entangled photon-pair source obtained via a type-II non-collinear quasi-phase-matched spontaneous parametric down-conversion process with a 10-mm periodically poled KTiOPO4 crystal, which is as stable and wavelength-tunable as the well-known Sagnac configuration scheme. A brightness of 4.2 kHz/mW is detected and a concurrence of 0.975 is estimated using quantum sta...

Retrieving information from remotely sensed data is an important task. In the present work, data of L band microwave radiometer has been used to collect the brightness temperature over bare and vegetated fields in two polarizations at different moisture levels. Artificial neural network (ANN) trained with Levenberg-Marquardt algorithm has been used to determine soil moisture from brightness tem...

The hottest frequency region in terms of research currently lies in the 'frequency gap' region between microwaves and infrared: terahertz waves. Although new methods for generating terahertz radiation have been developed, most sources cannot generate high-brightness terahertz beams. Here we demonstrate the generation of ultrabright terahertz waves (brightness ~0.2 GW/sr·cm(2), brightness temper...

Wen LU, Shao-bo WANG, Rui WANG Institute of Meteorology & oceanography, PLA University of Science & Technology, Nanjing 211101, China Introduction: WindSat is the first spaceborne fully polarimetric microwave radiometer in the world. It can measure the third and fourth Stokes parameters of the target and provide a new way for sea ice remote sensing. By using WindSat data in 2004, we studied on ...

A partial decrease of the convective energy by the magnetic field of a sunspot causes the temperature of the magnetized plasma to decrease and this leads to a magneto-hydrostatic equilibrium. Thus, we expect a strong relation between magnetic field strength of a sunspot and its temperature/brightness. Here, we investigate this relation in the umbra of the large sunspot in NOAA10930 using spectr...

The atmospheric transmittance model for AMSU and HSB channels on the Aqua spacecraft uses a polynomial approximation to the temperature dependence of oxygen-band opacity within atmospheric layers. It uses look-up tables to calculate local water-vapor line intensity and pressure-broadening parameters as well as contributions to absorption from the water-vapor continuum, distant lines, and cloud ...

Context. The continuum intensity at wavelengths around 1 mm provides an excellent way to probe the solar chromosphere and thus valuable input for the ongoing controversy on the thermal structure and the dynamics of this layer. Aims. The synthetic continuum intensity maps for near-millimetre wavelengths presented here demonstrate the potential of future observations of the small-scale structure ...

Calibration and retrieval are two important and critical techniques for groundbased atmospheric microwave sounder. Adopting proper calibration methods will ensure a high sounding resolution. The paper uses two calibrated methods like LN2 (22–31 GHz and 51– 59GHz) calibration and sky tipping (22–31 GHz) to realize periodic calibration and using noise injection and in-built blackbody to realize i...