Data acquisition system(DAS).
For atmospheric variables and cloud parameter measurement the aircrafts are equipped with the measuring-calculating complex (Fig. 1). This complex includes aircraft novigation system for the current vehicle position and control of flight parameters of the aircraft (height, ground speed, true airspeed, angle of drift and etc.) and a set of meteorological sensors for the basic thermodynamic and microphysical characteristics of the atmosphere and clouds registration. Aircraft navigation system consists of satellite GPS receivers "TRANSPAK-II" or "GARMIN", doppler DISS-013 and a board of system of air signals, built-in computer and compact receivers of static pressure, dynamic pressure and the temperature meter block connected to the platinum temperature gauge P-104. The set of meteorological sensors includes cloud water content meter (LWC/TWC), cloud transparencymeter RP, and aircraft condensation hygrometer ACH, intended for measurement of temperature of a dew point. The gauges of measuring devices are installed on the plug or on the top hatch of the aircraft (Fig. 2.)
All measuring systems are connected to the personal computer (Fig. 3.), which process information and store all variables in real time.
Different options of DAS allow to receive in real time following parameters of the atmosphere and clouds:
| № | Kind of parameter | Measuring parameter | Estimated characteristics |
| 1 | Navigation parameters | Time | 1. Wind velocity 2. Wind direction 3. Relative humidity Vertical stratification of: 1. Temperature 2. Dewpoint temperature 3. Humidity 4. Wind velocity 5. Wind direction 6. Unstable and inversion layers |
| 2 | Geographical coordinates | ||
| 3 | Track | ||
| 4 | Course | ||
| 5 | Angle of drift | ||
| 6 | Azimuth from anchor point | ||
| 7 | Distanse from anchor point | ||
| 8 | Barometric height | ||
| 9 | Ground speed | ||
| 10 | Thermodynamic parameters | Airspeed | |
| 11 | Actual temperature | ||
| 12 | Dewpoint temperature | ||
| 13 | Microphysical parameters | Liquid water content | 1.Liquid water content LWC 2. Ice water content IWC 3. Effective diameter of cloud liquid Cloud liquid concentration |
| 14 | Total (liquid plus ice) water content | ||
| 15 | Extinction coefficient | ||
| 16 | Special parameters | Location and kind of influence | Transfer of zones of influence |
Fig. 1. Data acquisition system installed on An-30.
FIG. 2. Sensors: LWC/TWC (1), temperature meter (2) and ACH (3).
Fig. 3 Function chart of DAS