README file for the roti15min_jpl data set
The rate of TEC index (ROTI) [1, 2] characterizes TEC fluctuations observed along
receiver-to-satellite line of sight links over a 5-minute interval. The measurement
is obtained by processing GNSS dual-frequency phase data and computing the standard
deviation of the rate of TEC change over that interval after removing its background
variation trend. The ROTI data are provided in CDF format by Xiaoqing Pi of the Jet
Propulsion Laboratory.
ROTI data are provided as global maps using a 2.5 x 5 degree (geographic
latitude x longitude) grid. The median ROTI value is calculated in each bin. GNSS
data contributing to the ROTI computation are primarily collected from the global
network of International GNSS Service and the regional network of Continuous
Operating Reference Station (CORS).
References
1. Pi, X., A. J. Mannucci, U. J. Lindqwister, and C. M. Ho, Monitoring of global
ionospheric irregularities using the worldwide GPS network, Geophys. Res. Lett.,
24, 2283, 1997.
2. Pi, X., F. J. Meyer, K. Chotoo, Anthony Freeman, R. G. Caton, and C. T.
Bridgwood, Impact of ionospheric scintillation on Spaceborne SAR observations
studied using GNSS, Proc. ION-GNSS, pp.1998-2006, 2012.