− A numerical model of a general purpose commercial equipment for current versus voltage (I-V) and differential capacitance versus voltage (C-V) measurement of active devices is presented. The good agreement between the model results and experimental data show that the model takes into account the main error sources of the instrument and can be used as a base to perform error correction and to ...

The dynamic range and error performance of the diode power detector used to denormalise the digital correlations in interferometric radiometers is analysed by means of a second-order model of the diode response. This gives an easy method to establish system dynamic range as a trade-off between both the error contribution of measurement uncertainty and diode nonlinearity. The method is illustrat...

This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the m...

This paper will describe the SMOS concept in terms of instrument (characteristics) investigates the main aspects of the retrieval capabilities of the 2-D microwave interferometer for monitoring soil moisture, vegetation biomass and surface temperature. The analysis is based on model inversion taking into account the instrument characteristics. The standard error of estimate of the surface varia...

We have performed an initial assessment of the alignment status of the UVIS-1and IR-2 flight detectors as mounted in WFC3 during the first instrument-level thermal-vac test. Both detectors are found to be aligned out of tolerance, indicating errors in the transfer of surrogate alignment information to the flight articles. Measurements made at various times through the thermal vac test, with the...

This paper proposes a new instrumental variables estimator for a dynamic panel model with …xed e¤ects with good bias and mean squared error properties even when identi…cation of the model becomes weak near the unit circle. We adopt a weak instrument asymptotic approximation to study the behavior of various estimators near the unit circle. We show that an estimator based on long di¤erencing the ...