[Seisunix] Help with getting headerword

Hello Everyone,

Greetings. I have a su file where sy header is missing. How can I set a correcect sy values? I went through sushw and suchw and saw some basic information. I tried Key1=sy, key2=sx and key3=gx but noticed that I got gy values but gx and gy are same which is not supposed to be. I do not know the first value of gy. I request you to help me to set gy values.

Thank you.

Sincerely, Elora