struct segy {	int tr_seg_num;	int reel_tr_seg_num;	int orig_fld_num;	int tr_num_orig_rec;	int energy_src_pnt;	int CDP_num;	int tr_num_CDP;	short tr_id;	short num_vert_tr;	short num_hor_tr;	short data_use;	int dist_from_src;	int rec_grp_elev;	int src_surf_elev;	int src_depth;	int datum_elev_rec_grp;	int datum_elev_src;	int water_depth_src;	int water_depth_group;	short elev_depth_scaler;	short coordinate_scaler;	int src_coordinate_x;        int src_coordinate_y;         int grp_coordinate_x;         int grp_coordinate_y; 	short coordinate_units;	short weathering_vel;	short subweathering_vel;	short uphole_time_src;	short uphole_time_grp;		short src_static_correction;	short grp_static_correction;	short tot_static_applied;	short lag_time_A;	short lag_time_B;	short delay_recording_time;	short mute_time_start;	short mute_time_end;	short number_of_samples;	short sample_interval;	short gain_type;	short inst_gain_const;	short early_initial_gain;	short correlated;	short sweep_freq_start;	short sweep_freq_end;	short sweep_length;	short sweep_type;	short sweep_trace_taper_length_start;	short sweep_trace_taper_length_end;		short taper_type;	short alias_filter_freq;	short alias_filter_slope;	short notch_filter_freq;         short notch_filter_slope; 	short low_cut_freq;	short high_cut_freq;        short low_cut_slope;        short high_cut_slope; 	short year_data_recorded;	short day_of_year;	short hour;	short minute;	short second;	short tmz;	short trace_weighting;	short geophone_grp_num_roll_switch;	short geophone_grp_num_trace_num;	short geophone_grp_num_last_trace;	short gap_size;	short over_travel;	union 	{		char  buffer[59];		struct passcal_stuff		{			char stn[6];			char sensor_serial[8];			char chn[4];			short tot_static_hi;			int sample_rate;			short int_size_flag;			short start_tr_ms;			short event_time_yr;			short event_time_day;			short event_time_hour;			short event_time_min;			short event_time_sec;			short event_time_ms;			float scale_factor;			short inst_no;			short filler;			int num_samples;			int max_samp;			int min_samp;		} p_stuff;	} comment;};