Precise wide area ionosphere correction solution for multi-spectrum alternative sources of space based PNT signals

A method for correcting for ionosphere-induced errors in a positioning, navigation, and timing signal received at a single frequency, the method comprising the step of producing a reference Vertical Total Electronic Content contour map centered with respect to a single dual-frequency reference receiver and extending out to the visible horizon with respect to that reference receiver and wherein the step of producing a Vertical Total Electronic Content contour map centered with respect to a single dual-frequency reference receiver and extending out to the visible horizon with respect to that reference receiver further comprises the steps of:

• identifying a reference receiver;
• from a plurality of space vehicles, receiving a reference positioning, navigation, and timing signal from each space vehicle of the plurality of space vehicles at least two frequencies;
• for each space vehicle of the plurality of space vehicles, measuring an ionosphere delay from a dual-frequency measurement;
• determining the inter-frequency bias of the reference receiver;
• for each space vehicle of the plurality of space vehicles, calculating a Vertical Total Electronic Content at an Ionosphere Pierce Point of the space vehicle relative to the reference receiver;
• determining a reference Vertical Total Electronic Content contour map comprising thirteen points using a three-stage extrapolation process through the use of Delauney triangulation wherein the thirteen points correspond to the reference receiver, a location of each of four space vehicles, four cardinal points on the visible horizon and four intercardinal points on the visible horizon and wherein the three-stage extrapolation process comprises a first Delauney triangulation of reference receiver location and space vehicle location, an extrapolation of Vertical Total Electronic Content to the visible horizon and a second Delauney triangulation including a plurality of extrapolated points on the horizon and employing the reference Vertical Total Electronic Content contour map at a user receiver to correct for ionosphere induced errors in a positioning, navigation, and timing signal received at a single frequency.