Pressure jump at launch

The difference between the first pressure value recorded by the radiosonde
after launch (984.5) that the surface value entered by the operator (989.3)
is somewhat larger than would normally be expected.  This will result in
incorrect altitude values throughout the sounding.  The ascent rates
during the first 30 seconds also will be incorrect.

• V wind component(v_wind)
• Wind status(wstat)
• North Latitude(lat)
• base time in epoch(base_time)
• -180.0 - +180.0(alt)
• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon(lon)
• Wind Direction(deg)
• Ascent rate(asc)
• Relative Humidity (hybrid-b grid)(rh)
• Wind Speed(wspd)
• Easterly Wind Component(u_wind)
• Time offset from base_time(time_offset)
• Retrieved pressure profile(pres)