In this comment, it is shown that Zhu et. al. had misinterpreted some double difference bases (DDBs) as twofold redundancy arrays (TFRAs). The baselines of most DDBs listed in Table I of the above communication get disrupted/broken in the event of single-element failures, thereby failing on the very promise of TFRAs to be robust against single-sensor failures. The use of robust minimum redundancy arrays (RMRAs) is suggested as an alternative solution.

This paper is a comment to the article “A Novel Designed Sparse Array for Noncircular Sources with High Degree of Freedom” published by Mathematical Problems in Engineering Journal of Hindawi publishers. This comment identifies a few errors made by the authors of the above paper and provides suitable corrective measures.