Albin J Gasiewski

US Patent:

6377207, Apr 23, 2002

Filed:

Sep 27, 2000

Appl. No.:

09/671665

Inventors:

Fredrick S. Solheim - Boulder CO 80303
Albin J. Gasiewski - Boulder CO 80302

International Classification:

G01W 102

US Classification:

342351, 342 26, 342192, 342195, 324640, 7317016, 7317026

Abstract:

The passive polarimetric microwave radiometer is a simple and low cost radiometric icing detection system that operates over a suitable set of frequency bands in the millimeter wave region of the spectrum to provide useful signatures for detecting aircraft icing conditions. This basic passive polarimetric microwave radiometer observes along a single line of sight and consists of a dual polarization dual frequency radiometer that is pointed in the direction of interest, such as the projected flight path, and operates at a frequency which is sensitive to the polarizing effects of hydrometeors. The passive polarimetric microwave radiometer could also observe in a horizontal plane around the aircraft or ground station and include both vertical and horizontal scanning capability. By utilizing polarimetric observations near two widely separated lines at frequencies with matching attenuations (and therefore matching range sensitivities) a stronger spectral signal providing information on hydrometeor habit (size and shape) can be obtained. Such additional information is especially important to characterize volumes containing mixed phases of liquid water and ice (wetted ice crystals, or interspersed ice and liquid hydrometeors) and for determining hydrometeor shapes and size distributions.

US Patent:

20060214843, Sep 28, 2006

Filed:

Mar 25, 2005

Appl. No.:

10/907258

Inventors:

Marian Klein - Boulder CO, US
Albin Gasiewski - Boulder CO, US

International Classification:

G01S 3/02

US Classification:

342351000

Abstract:

This invention describes a design of a structure that allows microwave radiometers to be calibrated under all conditions of weather and atmospheric fallout. The thermal emission standards radiating surfaces are kept free of hydrometeors (liquid water, ice, or snow), dust, dirt, soot, oils, ash, or other organic and inorganic matter during extended operation. Meanwhile, the radiometer are allowed an unobstructed view of scene under observation, for example, the entire sky from horizon to horizon as well as most of the ground underneath. The effects of any attenuating or scattering matter that accumulates on the elements of the beam forming system are compensated for since the thermal emission standards are viewed in front of the first element of beam forming system (e.g. lens, radome, protective window). In this manner the same amount of dirt, hydrometeors, etc. on radiometer first element of beam forming system as present during the viewing of the scene under observation will be present during calibration. The thermal emission standards' radiating surfaces are kept clean and free of attenuating or scattering matter, thus the precision, stability, and radiation characteristics of thermal reference are maintained.

US Patent:

52314049, Jul 27, 1993

Filed:

Mar 6, 1992

Appl. No.:

7/847349

Inventors:

Albin J. Gasiewski - Atlanta GA

Assignee:

Georgia Tech Research Corporation - Atlanta GA

International Classification:

G01B 302

US Classification:

342351

Abstract:

A dual linearly-polarized cross-correlating radiometer including an apparatus for calibrating the cross-correlating channel of the radiometer is described. The apparatus for calibrating the cross-correlating channel comprises a first calibration load, a second calibration load positioned perpendicularly thereto, and means for rotating the calibration loads relative to the feedhorn of the radiometer. The calibration loads are moved through several angular positions and the output voltages of the cross-correlating channel are measured at the various angular positions and used to estimate the gains and offset of the cross-correlating channel.