Estimation of single station interfrequency receiver bias using GPS-TEC

Dual-frequency Global Positioning System (GPS) receivers present a plausible and cost-effective way of computing Total Electron Content (TEC). For accurate estimates of TEC, frequency-dependent satellite and receiver instrumental biases should be removed from GPS measurements properly. Although instrumental satellite bias values are widely available through the internet from various International GPS Service (IGS) analysis centers, receiver biases (also known as differential code biases or interfrequency biases) are provided only for a very few GPS stations and a select number of days. This makes it very difficult to compute TEC for a single station. In this study, an online, single station receiver bias estimation algorithm, IONOLAB-BIAS, is developed and implemented to obtain daily and monthly averages of receiver bias. The algorithm is successfully applied to both quiet and disturbed days of the ionosphere for stations positioned in high-latitude, midlatitude, and equatorial regions. The receiver bias estimates are compared with two of the basic methods in the literature that can be applied off-line, and also with the receiver bias values provided from the IGS centers for a select number of stations. It is observed that IONOLAB-BIAS is in excellent accordance with the sparse estimates from the IGS centers for all ionospheric states and regions. IONOLAB-BIAS has a high potential to be an alternative receiver bias computation algorithm with its ease of implementation and accurate estimates for any single station GPS-TEC.