Microwave Radiometer Resolution Optimization Using Variable Observation Times

Abstract

This manuscript first revises the performance of total power, Dicke-type and noise-injection microwave radiometers. Equations for the radiometric resolution are revised or derived, and their performance in terms of the radiometric resolution improvement with respect to the ideal total power radiometer resolution is evaluated. It is then shown that the radiometric resolution of noise-injection radiometers can be optimized by adjusting dynamically the integration times devoted to the three measurements: antenna, antenna plus noise, and reference load. Numerical results are then presented to illustrate the dependence of the radiometric resolution with different instrument parameters. Experimental results are finally presented to corroborate the predicted performance. It is also shown that in many cases of interest these integration times can be set to a constant value with little degradation with respect to the optimum case, but better than the case in which the total integration time is divided in three equal subintervals.

Fluctuation sensitivity models of microwave radiometers

“…As compared to the full-power radiometer, the structural scheme of a Dicke's radiometer (see Fig. 2) is fitted with an additional switch (SW), noise generator (NG) and synchronous detector (SD) [2]. If we take into account the parameters of the switch, then sensitivity ΔT A , of the Dicke's radiometer is determined via the following formula:…”

“…A special case in radiophysical sensing implements the null method of measurement where the last summon of formula (2) is reduced to zero (applicable to (2) where T A =T NG ) thus making high stability radiometers based on this method possible [3]. Fig.…”

AWARDS: Advanced microwave radiometers for deep space stations

“…It increases proportionally to the system noise temperature T sys , being the sum of the receiver noise temperature T R and the temperature of the reference load T REF observed by the antenna. The radiometric resolution is reduced with increasing bandwidth B and integration time t [7]:…”

Радіометрична Ідентифікація Гранульованих Речовин

“…Works [9,10] showed a general possibility of remote identification of different liquids based on their thermal profiles (TPs), including explosives, sealed in dielectric containers (packaging), by the methods of close location [11][12][13][14][15][16][17][18]. This article examines samples of GMs as a particular case of unstructured (disordered) systems.…”