Pressure jump at launch

The difference between the first pressure value reported by the sonde
after launch (943.7) and the surface pressure (949.2) is larger than
expected.  The absolute altitude for this sounding and the ascent rates
during the first 30 seconds will likely be incorrect.

• Ascent rate(asc)
• Retrieved pressure profile(pres)
• -180.0 - +180.0(alt)

• Retrieved pressure profile(pres)
• -180.0 - +180.0(alt)
• Ascent rate(asc)

• (Raw data stream - documentation not supported)