Remote-Sensing of Solar Wind Speeds from IPS Observations at 140 and 327 MHz Using MEXART and STEL

Interplanetary scintillation (IPS) is used to probe solar wind speeds in the inner heliosphere by applying either of two generalized data-analysis techniques: model fitting to power spectra (MFPS) from a single station, or cross-correlation functions (CCF) produced by cross-correlating two simultaneous IPS time series from separate stations. The MEXican Array Radio Telescope (MEXART), observing at 140 MHz, is starting to use an MFPS technique. Here we report the first successful solar wind speed determinations with IPS observations by MEXART. Three stations of the Solar-Terrestrial Environment Laboratory (STEL), observing at 327 MHz, use a CCF, and an MFPS technique is also used at one of these sites. We here analyze data from MEXART and from one antenna of STEL to obtain solar wind speeds using an MFPS technique from a single station. The IPS observations were carried out with radio source 3C48 during Solar Cycle 24. The MFPS method we describe here is tested by comparing its obtained speeds with those from the STEL CCF technique. We find that the speeds from the two techniques generally agree within the estimated errors.