Limerick Flying Club weather station powered by ubiworx™ sensor gateway.

Limerick Flying Club provides a way for people to learn how to fly and to maintain their flying skills in professional but sociable surroundings. The club is a Registered Training Facility based at Coonagh Airfield (EICN) on the outskirts of Limerick in Ireland.

Overview

An important consideration in flying is weather. To help understand live weather conditions and to maintain a record of past weather conditions, Limerick Flying Club uses a small robust weather station mounted on a high pole near its runway. The weather station is connected to an Emutex ubiworx™ powered sensor gateway. The gateway enables users to inspect live and historic weather data using smartphone apps and web apps. Click here to visit the club’s weather web page.

The weather station application at Limerick Flying Club is a very interesting ubiworx™ use case that is a good example of using edge device processing to prepare data before transmission to the cloud. The weather station is an Oregon Scientific WMR88 Weather Station with an anemometer (to measure wind speed), a wind direction indicator, a rainfall rate detector, a pressure detector, a thermometer and a relative humidity detector. The ubiworx™ data acquisition framework is used to gather the raw data, pre-process, scale and transmit the resulting information to the cloud for display on a publicly accessible web site.

How it works?

All the measurement instruments connect wirelessly to the Oregon Scientific base station to give a local display. The base station is connected via USB to an Emutex ubiworx gateway device, with embedded Linux system, which can have a wired (ADSL) or wireless (cellular) internet connection. Custom Lua scripts running on the ubiworx™ device perform several local analytic functions on the acquired data. Pilots of light aircraft are very interested in wind speed and direction and therefore several wind data streams are created. The wind speed is scaled to knots and averaged over 10 minute and 30 minute intervals. A cross wind component is calculated based on the locally configured runway orientation. The wind direction is also averaged. This is particularly important as the Oregon WMR direction indicator only has 16 positions which would only give a raw accuracy of 22.5 degrees. By calculating a moving average over a 10 minute sliding window a more accurate representation of wind direction can be presented. In addition to wind the pressure reading trend is reported which can be forecast improving or deteriorating weather and the temperature and dew point can be used to estimate the cloud base height.

The resulting information streams are stored to a local SQL database on the ubiworx™ flash file system. The data points are timestamped as they are stored. Queries from the cloud application collect the data streams for display on the club website. The local storage ensures that a continuous picture of information parameters over time can be obtained even when there are periods of cellular communication outage as no data is ever lost. Finally a simple PHP application running on the club web site queries the ubiworx™ cloud API to publish graphs of the data streams.

The benefit to the club is that by using Emutex ubiworx™ to acquire and present useful information on a public web site or smart phone apps, pilots can get a current and accurate picture of local weather before leaving home.