New algorithms to estimate electron temperature and electron density with contaminated DC Langmuir probe onboard CubeSat

Three algorithms are developed to process the response current of pulsed Langmuir probes (PLPs) onboard satellites estimating ideal pulse current, residual voltage, and the electron temperature (Te) and electron density (Ne) in the ionosphere. The contaminated layer on the probe surface could result in LPs obtaining unreliable Te and Ne. The PLP is designed to solve this problem, and however, the rise time of pulse signals not approaching to zero will still bring some errors. Meanwhile, after each pulse scan, it requires a certain period for discharging, which affects the spatial resolution of PLP measurements. To resolve these problems, three algorithms estimate the ideal pulse response current, calculate the contaminated layer residual voltage to shorten the inter pulse scan period, and compute Te and Ne accordingly. Measurements of the DMSP (Defense Meteorological Satellite Program) are used to validate the performance of the proposed algorithms. Results show that the error of Te and Ne can be reduced down to 5% each, and the scanning rate can be increased by about 5–50 times.