▁which ▁is ▁the ▁orthogonal ▁complement ▁of ▁. ▁The ▁dis adv antages ▁to ▁this ▁approach ▁include ▁alter ing ▁the ▁vis ib ilities ▁cov ar iance ▁matrix ▁and ▁color ing ▁the ▁white ▁noise ▁term . ▁ ▁Sp atial ▁wh iten ing ▁ ▁This ▁scheme ▁attempts ▁to ▁make ▁the ▁inter ference - plus - no ise ▁term ▁spect r ally ▁white . ▁To ▁do ▁this , ▁left ▁and ▁right ▁multiply ▁ ▁with ▁inverse ▁square ▁root ▁factors ▁of ▁the ▁inter ference - plus - no ise ▁terms . ▁ ▁The ▁calculation ▁requires ▁rig orous ▁matrix ▁manip ulations , ▁but ▁results ▁in ▁an ▁expression ▁of ▁the ▁form : ▁ ▁This ▁approach ▁requires ▁much ▁more ▁computation ally ▁int ensive ▁matrix ▁manip ulations , ▁and ▁again ▁the ▁vis ib ilities ▁cov ar iance ▁matrix ▁is ▁alter ed . ▁ ▁Sub tra ction ▁of ▁inter ference ▁estimate ▁ ▁Since ▁ ▁is ▁unknown , ▁the ▁best ▁estimate ▁is ▁the ▁dominant ▁eigen vector ▁ ▁of ▁the ▁eigen - de com position ▁of ▁, ▁and ▁like wise ▁the ▁best ▁estimate ▁of ▁the ▁inter ference ▁power ▁is ▁, ▁where ▁ ▁is ▁the ▁dominant ▁eigen value ▁of ▁. ▁One ▁can ▁subtract ▁the ▁inter ference ▁term ▁from ▁the ▁signal ▁cov ar iance ▁matrix : ▁ ▁By ▁right ▁and ▁left ▁multip lying ▁: ▁ ▁where ▁ ▁by ▁selecting ▁the ▁appropriate ▁. ▁This ▁scheme ▁requires ▁an ▁accurate ▁estimation ▁of ▁the ▁inter ference ▁term , ▁but ▁does ▁not ▁alter ▁the ▁noise ▁or ▁sources ▁term . ▁ ▁Sum mary ▁ ▁Array ▁processing ▁technique ▁represents ▁a ▁break through ▁in ▁signal ▁processing .