TRN revisited: A systematic design of a GPS inspired adaptive tracking loop

At the time that TRN was originally proposed, designed and implemented, the possibility to use digital signal processing techniques was virtually non-existent. As a result, only rather basic correlation techniques could be used to keep track of terrain elevation signals. Likewise, early GPS receivers used a rather simple analogue early-late tracker to keep the reference code in lock with the received code. With the tremendous increase in DSP capabilities, more advanced signal processing concepts were introduced for GPS code tracking. Conventional schemes were unable to detect distortions (i.e. multipath, interference), whereas more advanced digital processing schemes could both detect and compensate for them. In contrast, in the TRN area, the advantages of DSP capabilities seem to have not been exploited to such an extent. The increase in real- time processing power, the availability of compact, large storage capabilities, the existence of hi- resolution elevation maps and the developments in the area of sensors are important enablers that warrant a re-investigation of the current potential of the TRN technology. This observation led to the definition of a research project that specifically aims to explore how to benefit from these enablers. A TRN algorithm inspired by GPS signal processing concepts has been developed. However, differences between the two types of signals require additional consideration in adapting GPS concepts to TRN.