Joint domain localisation (JDL) is a popular reduced-dimension space-time adaptive processing (STAP) technique for clutter suppression in an air-borne radar system. Here. the authors develop an improved JDL method by exploiting persymmetric covariance matrix. referred to as persymmetric joint domain localisation (Per-JDL). https://foldlyers.shop/product-category/non-contact-testers/