typedef struct {
int month; /* Date for this ray; month (1-12). */
int day; /* Date for this ray; day (1-31). */
int year; /* Date for this ray; year (eg. 1993). */
int hour; /* Time for this ray; hour (0-23). */
int minute;/* Time for this ray; minute (0-59).*/
float sec; /* Time for this ray; second + fraction of second. */
float unam_rng; /* Unambiguous range. (KM). */
float azimuth; /* Azimuth angle. (degrees). Must be positive
* 0=North, 90=east, -90/270=west.
* This angle is the mean azimuth for the whole ray.
* Eg. for NSIG the beginning and end azimuths are
* averaged.
*/
int ray_num; /* Ray no. within elevation scan. */
float elev; /* Elevation angle. (degrees). */
int elev_num; /* Elevation no. within volume scan. */
int range_bin1; /* Range to first gate.(meters) */
int gate_size; /* Data gate size (meters)*/
float vel_res; /* Doppler velocity resolution */
float sweep_rate; /* Sweep rate. Full sweeps/min. */
int prf; /* Pulse repitition frequency, in Hz. */
int prf2; /* Second PRF, for Sigmet dual PRF. */
float azim_rate; /* Sweep rate in degrees/second.*/
float fix_angle; /* Elevation angle for the sweep. (degrees). */
float pitch; /* Pitch angle. */
float roll; /* Roll angle. */
float heading; /* Heading. */
float pitch_rate; /* (angle/sec) */
float roll_rate; /* (angle/sec) */
float heading_rate; /* (angle/sec) */
float lat; /* Latitude (degrees) */
float lon; /* Longitude (degrees) */
int alt; /* Altitude (m) */
float rvc; /* Radial velocity correction (m/sec) */
float vel_east; /* Platform velocity to the east (negative for west) (m/sec) */
float vel_north; /* Platform velocity to the north (negative for south) (m/sec) */
float vel_up; /* Platform velocity toward up (negative for down) (m/sec) */
float pulse_count; /* Pulses used in a single dwell time. */
float pulse_width; /* Pulse width (micro-sec). */
float beam_width; /* Beamwidth in degrees. */
float frequency; /* Bandwidth GHz. */
float wavelength; /* Wavelength. Meters. */
float nyq_vel; /* Nyquist velocity. m/s */
float (*f)(Range x); /* Data conversion function. f(x). */
Range (*invf)(float x); /* Data conversion function. invf(x). */
int nbins; /* Number of array elements for 'Range'. */
} Ray_header;