Gathering synoptic weather observation data over the oceans is an important complement to meteorological upper-air observation. The Vaisala ASAP Station is a semi-automatic shipboard weather station that is designed for ocean-going ships that participate in the Automated Shipboard Aerological Program (ASAP). The Vaisala ASAP Station allows upper-air observations to be made over the oceans from cargo ships and other marine vessels at reasonable cost. The vessels enlisted in the ASAP program typically make two launches per day from the Vaisala ASAP Station. Some perform up to four.

The Vaisala ASAP Station is semi-automatic: an operator must oversee the filling and launching of the balloon-borne radiosondes. Thereafter, the process is automatic. The Vaisala ASAP Station receives the radiosonde signals and processes them into meteorological messages. It transmits the messages in standard WMO message format (TEMP SHIP). The messages are relayed to the Global Telecommunication System (GTS) for international meteorological use.

Vaisala automatic weather stations can be integrated in order to bring surface weather data into the system for sending SYNOP SHIP messages. The Vaisala ASAP Station can be fitted on ships of various types, and it operates reliably under changing environmental conditions. The operator room houses the Vaisala sounding equipment (Vaisala DigiCORA® Sounding System MW41), a satellite transceiver and instruments for making surface weather observations.