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The scintillation modeling code WBMOD, developed at North West Research, provides a global description of scintillation occurrence. However, the model has had limited calibration globally. Thus its performance in localized regions such as Australia-Southeast Asia is required to be evaluated. The Defence Science and Technology Organisation, Australia, in conjunction with Indonesian National Institute of Aeronautics and Space (LAPAN), Defence Science and Technology Centre, Malaysia, Air Force Research laboratory, United States, and IPS Radio and Space Services of Australia, has commissioned a network of GPS receivers to measure scintillation from sites in the region. One of the objectives of this deployment is to carry out a validation of WBMOD in the region. This paper describes the network of GPS receivers used to record the scintillation data. The details of the procedure used to validate WBMOD are given and results of the validation are presented for data collected during 1998 and 1999 from two sites, one situated in the southern anomaly region and the other situated near the geomagnetic equator. We found good overall agreement between WBMOD and the observations for low sunspot numbers at both sites, although some differences were noted, the major one being that the scintillation activity predicted by WBMOD tended to cut off too early in the night. At higher levels of sunspot activity, while WBMOD agreed with the observations in the southern anomaly region, we found that it significantly underestimated the level of scintillation activity at the geomagnetic equator. |
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