TY - JOUR T1 - Navigation using carrier Doppler shift from a LEO constellation: TRANSIT on steroids JF - NAVIGATION: Journal of the Institute of Navigation JO - NAVIGATION SP - 621 LP - 641 DO - 10.1002/navi.438 VL - 68 IS - 3 AU - Mark L. Psiaki Y1 - 2021/09/21 UR - https://navi.ion.org/content/68/3/621.abstract N2 - A new global navigation concept is studied that relies on carrier Doppler shift measurements from a large LEO constellation. This system could provide an alternative to pseudorange-based GNSS. The concept uses a high-fidelity model of received carrier Doppler shift. This model is used in a point-solution batch filter that simultaneously estimates eight unknowns: the three position vector components, receiver clock offset, three velocity vector components, and receiver clock offset rate. The filter uses eight or more measured Doppler shifts in its least-squares fit. A generalized Geometric Dilution of Precision (GDOP) analysis indicates that absolute position accuracies on the order of 1-5 meters and absolute velocity accuracies on the order of 0.01 m/sec to 0.05 m/sec may be achievable if the range-rate precision of the Doppler shift measurements is 0.01 m/sec. These accuracies are comparable to current pseudorange-based GNSS. Clock offset accuracy is on the order of 0.0001 to 0.0010 sec 1-𝜎. ER -