“…The field of hard X-ray polarimetry has been quite active in the last 10 − 15 years which can be seen through the new developments of dedicated polarimeters like SPR-N (Bogomolov et al, 2003;Zhitnik et al, 2006), POLAR (Sun et al, 2016), PoGOLite and PoGO+ , X-Calibur (Guo et al, 2011(Guo et al, , 2013, GRAPE (Bloser et al, 2009;Mc-Connell et al, 2009), GAP (Yonetoku et al, 2006), PENGUIN-M (Dergachev et al, 2009), COSI (Yang et al, 2018;Lowell et al, 2017) and a large number of new proposals to develop hard X-ray polarimeters, e.g. COSI-2 (Tomsick et al, 2019), POLAR-2 (Kole, 2019), Daksha 1 , AMEGO (McEnery et al, 2019) etc.…”