A. Piel et al., Plasma diagnostics with Langmuir probes in the equatorial ionosphere: I. The influence of surface contamination, J PHYS D, 34(17), 2001, pp. 2643-2649
The application of spherical Langmuir probes for measuring the electron tem
perature and density on ionospheric sounding rockets is discussed with resp
ect to the influence of the geomagnetic field effects and probe contaminati
on. The influence of the contamination layer is thoroughly analysed in the
frame of a nonlinear equivalent circuit. When operating the probe in ramp m
ode, it is found that the distortion of the current-voltage characteristic
is different for decreasing and increasing probe voltages. The resulting er
ror of the electron temperature is determined for a range of capacitance (C
) and resistance (R) values of the contamination layer. A method is describ
ed to determine the parameters R and C from the flight data. Further, a cor
rection algorithm is discussed that allows the true probe characteristic to
be retrieved from the measured distorted characteristic.