Radiometric Autonomous Navigation Fused with Optical for Deep Space Exploration

Abstract

With the advent of the Deep Space Atomic Clock, operationally accurate and reliable one-way radiometric data sent from a radio beacon (i.e., a DSN antenna or other spacecraft) and collected using a spacecraft's radio receiver enables the development and use of autonomous radio navigation. This work examines the fusion of radiometric data with optical data (i.e. OpNav) to yield robust and accurate trajectory solutions that include selected model reductions and computationally efficient navigation algorithms that can be readily adopted for onboard, autonomous navigation. The methodology is characterized using a representative high-fidelity simulation of deep space cruise, approach, and delivery to Mars. The results show that the combination of the two data types yields solutions that are almost an order of magnitude more accurate than those obtained using each data type by itself. Furthermore, the combined data solutions readily meet representative entry navigation requirements (in this case at Mars).

Comparison of Deep Space Navigation Using Optical Imaging, Pulsar Time-of-Arrival Tracking, and/or Radiometric Tracking

“…41 The third and fourth eigenvalues from the expansion (3) as a function of ξ 0 Fig. 42 The third and fourth eigenvalues from the expansion (4) as a function of ξ 0 Fig. 43 The third and fourth eigenvalues of for the full nonlinear case as a function of ξ 0 .…”

“…The navigation filter will also be optimally tuned for all the model errors that are present, use all available calibration data, and not require expanded filter compensation for reduced-order models (as would be the case for a true onboard implementation). For comparison, a recent paper by Ely, et al [42] thoroughly examined the onboard case with model simplifications and reduced calibration modeling (i.e., sub-optimal with filter compensations) that are sufficient for an autonomous navigation system with radio and/or optical data that supports this Mars cruise, approach, and entry problem. In the present paper, use of optimal modeling with matched filter process noise (i.e., the same that would be used by a ground-based navigation team) will allow for better identification of the relative merits of one-way radiometric, optical imaging, and pulsar TOA data without 'clouding' the interpretation of the results that reduced-order models and calibration data predicts would introduce.…”

“…Correct measurement partials need to account for this. Thorough discussions of this data type, associated errors, and its use for autonomous onboard navigation are presented in Ely [7,48]. The geometric path length ρ(t) is computed accurately using an iterative algorithm, as documented in Moyer [49].…”

Spacecraft autonomous navigation using line-of-sight directions of non-cooperative targets by improved Q-learning based extended Kalman filter

“…The radio navigation is a type of the widely used navigation approaches for spacecrafts, such as the ground-based radio navigation and the global navigation satellite system (GNSS), where the radiometric data sent from radio beacons (i.e., ground stations or GNSS satellites) with known position information, are collected using an onboard radio receiver to determine the position of the spacecraft. [1][2][3] However, the performance of the radio navigation is degraded in the radio signal denied environment. In order to cope with this problem, it is important to improve the autonomous navigation capability for the spacecraft without the support of the radio beacons, especially in cases of emergencies.…”

Determination of sky status by ground based radiometric data analysis

“…A similar work presented in (16) is effective provided there are no obstructions, and the variation in meteorological parameters is prominent and hence detectable by optical means with an acceptable degree of accuracy. The drawbacks of purely optical imaging can be addressed through a hybrid system which allows for radiometric sensing as well as optical imaging, used in deep space exploration (17) . Pyranometric measurement techniques have also been explored as a viable solution in (18) .…”