Krishna K.M.Johnson P.S.2021-05-052021-05-052021Journal of Pseudo-Differential Operators and Applications Vol. 12 , 1 , p. -https://doi.org/10.1007/s11868-021-00379-xhttps://idr.nitk.ac.in/handle/123456789/15911Characterizations for a frame and its duals are known for separable Hilbert spaces. In this paper, we characterize a class of approximate Schauder frame and its duals for separable Banach spaces. We also give an operator-theoretic characterization for similarity of ASFs. Our results encode the results of Holub, Li, Balan, Han, and Larson. We also address orthogonality of ASFs. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.Article