An attitude determination algorithm, proposed 25 years ago as a back-up algorithm in case the QUEST algorithm failed to function properly on its maiden mission, is finally compared with the QUEST algorithm. A comparison of the attitude determination accuracies of both algorithms is carried out using the QUEST measurement model. The back-up algorithm, which we have chosen to call “The Anti-QUEST,” while it lacks the special features that have made QUEST so popular today and is rather clumsy, slow and deficient in many ways, works well under the almost ideal conditions of the Magsat mission, but not generally. Further comparisons of QUEST and The Anti-QUEST provide useful insights into the different behaviors of optimal and deterministic attitude estimators. This work also presents useful practical techniques for the covariance analysis of nonoptimal algorithms.

中文翻译：

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QUEST和Anti-QUEST：善恶态度估计

最后，将一种姿态确定算法与QUEST算法进行比较，该姿态确定算法是25年前提出的，以防QUEST算法在其初次任务中无法正常运行时作为备用算法。使用QUEST测量模型对两种算法的姿态确定精度进行了比较。我们选择的备份算法称为“ Anti-QUEST”，但它缺乏使QUEST在今天如此流行的特殊功能，并且笨拙，缓慢且在许多方面都不足，在几乎理想的情况下可以很好地工作Magsat任务的条件，但不是一般情况。QUEST和The Anti-QUEST的进一步比较为了解最佳和确定性态度估计器的不同行为提供了有用的见解。