The generator matrix

 1  0  0  1  1  1  1  1  1  1  1 (a+1)X  0  1  1  1 (a+1)X  1  1  1  1  1  1  1  1 (a+1)X  1  1  1  1  1  1  1  1  1  1  1 (a+1)X  0  1  1  1  1  1 (a+1)X  1  1  1
 0  1  0  0  1  X (a+1)X+a a+1 (a+1)X+1 (a+1)X+1  a  1  1 (a+1)X+a (a+1)X+a+1  a  1  1 (a+1)X+a+1 a+1  a aX (a+1)X+a+1 aX+a+1  1  1 (a+1)X+1  X X+a+1  X (a+1)X X+1 (a+1)X+a+1 a+1  0  X aX+a  1  1 (a+1)X aX+1  1  1 X+a+1  1 aX+1  0  0
 0  0  1  1 a+1 (a+1)X+a a+1 X+a+1  a  0  X X+a+1  a X+1  0  a aX+1 X+1  a X+1 (a+1)X+a+1 a+1 X+a aX (a+1)X+1 (a+1)X+1 X+a aX+a  1 (a+1)X a+1 (a+1)X+a+1 a+1  a aX+a+1  1 (a+1)X+a aX+a+1 aX+a X+1  1 (a+1)X+a+1 X+a aX+1 aX (a+1)X  a  0
 0  0  0 (a+1)X  0  X aX  X  0  0  0 (a+1)X aX (a+1)X aX (a+1)X  0  X  0 aX aX (a+1)X (a+1)X  X aX  0  X (a+1)X (a+1)X aX  0  X (a+1)X  X aX  X aX  0  X (a+1)X  0 aX  0  0 (a+1)X aX (a+1)X  X
 0  0  0  0  X  0  0 aX aX (a+1)X  X  X (a+1)X (a+1)X (a+1)X aX  X  0 (a+1)X  0 aX  X  0 aX aX aX aX aX (a+1)X aX aX  X aX  0 (a+1)X (a+1)X  X  0  X  X  0  0 (a+1)X aX aX (a+1)X (a+1)X aX

generates a code of length 48 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 128.

Homogenous weight enumerator: w(x)=1x^0+285x^128+180x^129+72x^130+384x^131+1719x^132+852x^133+504x^134+1056x^135+4395x^136+1548x^137+852x^138+1992x^139+6201x^140+2304x^141+1440x^142+3120x^143+8181x^144+3420x^145+1728x^146+3456x^147+8199x^148+2628x^149+1224x^150+1968x^151+4689x^152+1092x^153+324x^154+312x^155+1017x^156+264x^157+51x^160+24x^164+24x^168+18x^172+6x^176+6x^180

The gray image is a linear code over GF(4) with n=192, k=8 and d=128.
This code was found by Heurico 1.16 in 13 seconds.