• Interactive MU Model - Online Computations and Plots
  • Virtual MU Radar - Realtime Ionosphere Prediction
  • MU Radar IS Observation and Data



  • The MU (Middle and Upper atmosphere) radar (34.8N, 136.1E) is a 46.5-MHz, pulse-modulated, monostatic, Doppler radar with an active phased-array antenna which consists of 475 Yagis. This MST radar is also designed to be able to observe the weak incoherent scatter (IS) from free electrons of the ionosphere. Measurements are made at 4 beam directions simultaneously.

    The MU Radar Ionosphere Model is based on the MU radar IS experiments taken between 1986 - 2003, and archived in the Madrigal Database (http://www.openmadrigal.org). So far models for electron density, ion and electron temperature have been created, using a bin-fit technique, similar to what has been used for the local Millstone Hill models. Details of the technique have been given in Regional and local ionospheric models based on Millstone Hill incoherent scatter radar data, Geophys. Res. Lett., 29(8), 10.1029 / 2002GL014678, 2002. (PDF file), and in Local Empirical Model of the E and F Region Ionosphere Based on 30 Years of Millstone Hill Incoherent Scatter Data

    The data were binned by month and local time in 1-hour increments. Least squares fits for model parameter profiles were then computed in each of the 12x24=288 bins. Ne profiles are piecewise-linear with 30 nodes between 200 - 600 km at 10 km spacing giving a fine height resolution, while Te and Ti profiles have 9 nodes at 228.50, 273.60, 318.70, 363.80, 408.90, 454.00, 499.10, 544.20, 589.30 km for which altitudes MU radar temperature data are always given. To increase the amount of data into statistics, each of the 12 monthly bins contains 3 month data from the current month plus before and after the month. There are relatively small amount of Te and Ti data which have been obtained from the separated 4-pulse experiments from the Barker-coded pulse Ne profile experiments. So for the temperature models, we have included data within 3 hours for each hourly bin, e.g., for the 1200LT bin, data are from 1000-1300 LT.

    The parameters are assumed to be linear in F10.7 for the previous day and the Ap index for the previous 3 hour period. The least squares fit yields model coefficients for each parameters. A 33 median filter in local time and season is then applied to these coefficients.

    The model can be provided to interested users with recovery FORTRAN codes and coefficient data files. It is also available for online interactive calculations and plots; the URL is http://madrigal.haystack.edu/models/MUisrm_form.html. Based on near realtime solar geophysical indices, a Virtual MU Radar (VMUR) is created which predicts the ionospheric conditions for Ne, Te and Ti at current local time as well as for the whole day at Shigaraki. The VMUR is at http://madrigal.haystack.edu/models/vmur/. Please contact Shunrong Zhang or John Holt for more details about the model.

  • The Middle and Upper Atmosphere (MU) radar belongs to and is operated by the Radio Science Center for Space and Atmosphere, RASC (now Research Institute for Sustainable Humanosphere, RISH) of Kyoto University.
  • The MU radar data has been obtained from Dr. Kawamura, and installed into and maintained with the MADRIGAL system at MIT Haystack Observatory.
  • The Millstone Hill incoherent scatter radar is supported by a cooperative agreement between the National Science Foundation and the Massachusetts Institute of Technology.

  • This project is based upon work supported by the National Science Foundation under Grant Number 0207748.
  • Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.