Direct Instantaneous Frequency Rate Estimation to Improve the Carrier Estimation Performance in Mars Entry, Descent, and Landing Flight

Abstract

This paper focuses on the carrier estimation performance improvement in Mars entry, descent, and landing (EDL) flights. Carrier reconstruction could be used for trajectory derivation and Martian atmosphere profile inversion, and is the critical information for mission operations, as it helps determine the flight status of the spacecraft, demodulate the downlink information. The current approach is maximum likelihood estimation based on a two-dimensional (2D) maximum energy search algorithm, which computes the grid energy over all the combinations of frequency cells and frequency rate cells among the search space. Although it has good performance on robust estimation, the frequency estimation accuracy is limited due to the short coherent integration. An instantaneous frequency rate tracking approach based on the cubic phase function (CPF) is proposed that directly estimates the instantaneous frequency rate over the frequency rate cells, followed by the frequency estimation among the frequency cells. A sequential estimation method is introduced to propose the sequential CPF statistics, which uses the a priori Doppler phase information to suppress the noise squaring loss inherent in the standard CPF statistics. Simulations have been made on the released Mars Science Laboratory EDL trajectory for the two approaches, which show that considerable estimation improvement has been achieved for aerobraking flight by the new algorithm.

Fast Three‐Dimensional Search Algorithm to Improve the Carrier Tracking Performance During the Entry, Descent, and Landing (EDL) Phase of Mars Probes

“…The flow of the algorithm based on the formula is shown in Figure 1. An example of peak detection is shown in The maximum energy search algorithm, that is, the frequency maximum likelihood estimator designed by JPL, has been discussed in detail in the literature (Hao, Cui, et al, 2018;Satorius et al, 2003). This is a brief introduction.…”

“…In addition, IFR estimation based on the sequential cubic phase function (SCPF) is also used in carrier tracking during the EDL phase of the Mars probe (Hao, Cui, et al., 2018). In this method, a priori Doppler phase model, which is derived from previous estimations, is used to generate the SCPF statistics.…”

“…Among the methods mentioned above, the method based on the frequency maximum likelihood estimator has the strongest weak‐signal tracking capability (Hao, Cui, et al., 2018). Therefore, in this paper, our proposed novel high‐performance carrier tracking method is based on the principle of frequency maximum likelihood.…”

High‐Precision Carrier Tracking Algorithm for Extremely Weak and High‐Dynamic Signals

“…Recently, an instantaneous frequency rate (IFR) estimator based on a sequential cubic phase function (SCPF) has been proposed (Hao, Cui, et al., 2018). Compared with the open loop maximum energy search method proposed by the JPL, this method has a significantly higher estimation accuracy, but its weak‐signal tracking capability is obviously worse and cannot fully meet the requirements of high‐precision carrier tracking during the EDL phase of Mars rovers.…”

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Recently, an instantaneous frequency rate (IFR) estimator based on a sequential cubic phase function (SCPF) has been proposed (Hao, Cui, et al, 2018). Compared with the open loop maximum energy search

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