AR TE M IS ) ▁hyp ers pect ral ▁im ager , ▁the ▁Ocean ▁Data ▁Te lem etry ▁Mic ros at ellite ▁Link ▁and ▁the ▁Space ▁Av ion ics ▁Ex periment . ▁ ▁Design ▁ ▁T ac S at - 3 ▁uses ▁a ▁standard ▁satellite ▁bus ▁developed ▁and ▁provided ▁by ▁AT K . ▁The ▁payload ▁consists ▁of ▁a ▁two ▁mirror ▁R itch ey – Chr ét ien ▁teles cope ▁plus ▁correction ▁opt ics , ▁with ▁a ▁focus ▁device ▁incorpor ated ▁in ▁the ▁secondary ▁mirror ▁unit , ▁and ▁with ▁a ▁sl it ▁Off ner ▁spect rom eter . ▁The ▁spect rom eter ▁uses ▁the ▁AR TE M IS ▁hyp ers pect ral ▁imag ing ▁sensor ▁( H SI ), ▁which ▁is ▁a ▁single ▁H g C d Te ▁F ocal ▁Pl ane ▁Array ▁covering ▁the ▁entire ▁V / N IR / SW IR ▁spectrum ▁from ▁ 4 0 0   nm ▁to ▁ 2 5 0 0   nm ▁at ▁a ▁uniform ▁resolution ▁of ▁ 5   nm . ▁AR TE M IS ▁measures ▁first ▁the ▁spectral ▁information ▁at ▁each ▁point ▁on ▁the ▁ground ▁in ▁ 4 0 0 ▁spectral ▁channels . ▁H SI ▁data ▁cub es ▁obtained ▁by ▁AR TE M IS ▁are ▁then ▁handled ▁by ▁a ▁re program m able ▁digital ▁signal ▁processor ▁with ▁ 1 6 ▁GB ▁data ▁storage ▁cap ability ▁to ▁generate ▁on - board ▁products ▁and ▁for ▁in - the ater ▁down link . ▁T ac S at - 3 ' s ▁main ▁focus ▁is ▁land - based ▁H