Improved Signals for Differential One-Way Range

This article describes the current limiting error source for Delta Differential One-way Range (ΔDOR), provides a means to reduce this error, and lists the benefits to deep space navigation. Particular advantages for Small Satellite class missions are addressed. The key idea is spreading the spacecraft DOR signal with a pseudonoise (PN) code to make the spacecraft signal spectrum closely resemble the spectrum of natural radio sources used for instrument calibration. How spectral differences affect the measurement are discussed. This article describes the general formulation for PN DOR signal design, and the specific X-band implementation of PN DOR on a software defined radio at JPL. Finally, a prototype implementation at Ka-band, providing even better performance, is presented.