subroutine da_write_biasprep(radbias)

   implicit none

   type (bias_type), intent(in)  :: radbias

   if (trace_use) call da_trace_entry("da_write_biasprep")

      write(unit=biasprep_unit) radbias%nchan,radbias%npred
      write(unit=biasprep_unit) radbias%platform_id , &
                                radbias%satellite_id, &
                                radbias%sensor_id,    &
                                radbias%year,radbias%month,&
                                radbias%day, radbias%hour, &
                                radbias%min, radbias%sec,  &
                                radbias%scanline, &
                                radbias%scanpos,  &
                                radbias%landmask, &
                                radbias%elevation,&
                                radbias%lat,radbias%lon, &
                                radbias%ps,radbias%t2m, &
                                radbias%q2m,radbias%tsk, &
                                radbias%tb(1:radbias%nchan), &
                                radbias%omb(1:radbias%nchan), &
                                radbias%bias(1:radbias%nchan), &
                                radbias%pred(1:radbias%npred), &
                                radbias%qc_flag(1:radbias%nchan), &
                                radbias%cloud_flag(1:radbias%nchan), &
                                radbias%surf_flag, radbias%clwp

   if (trace_use) call da_trace_exit("da_write_biasprep")

end subroutine da_write_biasprep