Conversion of Level 1.1 FBDR ALOS-2 data into Level 1.5UBDL

Hello All,
I wanted to convert Level 1.1 FBDR ALOS-2 PALSAR data into Level 1.5UBDL.
I tried but was unable to get the exact azimuth and range resolution after converting Level 1.1 data.
Kindly help me to guide through the procedure so for converting the same.