This image shows a gateway installed on top of a BBQ area in Bicentennial Park. Fixed to a tall pole to make certain it gets a great vantage point overlooking the grassy lawns, playgrounds and trees, the gateway is in the perfect spot to pick up data packets from all the sensors in this area.
SIMPaCT is aimed at bringing maximum coolth to Bicentennial Park during increasingly hot summers. To do this trees need to be at their optimum health, to enable them to transpire via their leaves. In the same away sweat helps cool down our bodies, transpiration occurs when tiny water droplets are converted to vapour and released into the atmosphere.
But how do we know when a tree is at its healthiest? How do we work out how much water is just the right amount? Water-saturated soil can drown a tree, preventing it from taking up oxygen. Prolonged water-logged soil can cause root rot and fungus, killing the roots and slowly starving the tree. Conversely, withholding water can slow growth and ultimately cause death.
To help measure optimum growing conditions SIMPaCT is using a combination of soil and microclimate sensors throughout the park to collect data. Each soil sensor is buried approximately 15cm below the surface of the ground, and microclimate sensors are installed approximately 3m above ground. Every fifteen minutes each sensor [over 250 of them] sends a data packet out into the atmosphere. Considering the size of the sensor and the fact they're powered by AAA batteries these packets can travel an astonishing distance using LoRa and LoRaWAN technology - up to 3km in urban areas! But this ability is hindered by buildings, undulating landscape and other factors that might hobble radio line-of-sight.
To pick up these data packets we have installed two gateways in the park. They are essentially acting as routers between IoT devices [the sensors, or end nodes] and the cloud [data servers]. A third gateway is to be installed in the nearby urban area, on the roof of a residential building. With its high vantage point, this third gateway will maximise coverage and make sure we don't have any black spots and are gathering as much information as possible. Ensuring good coverage will also maximise battery life - the better the signal, the less hard work the sensor needs to do to get its message to a gateway.
The image below shows a view across Bicentennial Park from one of the buildings in the urban area of Sydney Olympic Park. The terrain is full of dips and hollows, and includes many heavily treed areas - to ensure maximum coverage of the park RF [radio frequency] mapping was done to work out the best spots for the gateways.
Коментарі