The radiation mapping application has been developed using the directions of the experienced Interface Analysis Centre (IAC) researchers. It is a very specific application and in order to be useful and a real tool in the hands of the user, it has to be specifically defined and designed according to their needs.
The configuration screen displays all the useful information to the user (fig.1). In the fist part of the screen there is a message board that displays informative messages regarding the Bluetooth connection. In this display, the user can be informed about the availability of other BLE devices, the name of the device that they are eventually connected to and other relevant information. After a successful connection the RSSI value is continuously updated to reflect the signal strength of the Bluetooth connection between the measurement unit and the iPhone. At this point, with an active Bluetooth connection, the user can read the status of the measurement device in the iPhone screen. Consequently, when the GPS unit locks, both the relevant message and the number of the connected satellites will be displayed to the screen as a sign of the signal strength. Finally, there is a section related to data which come from the radiation spectrometer. In this part, the actual CPS value is reported together with total number of measurements that has been performed.
The next screen displays the visual representation of the measurements in a map (fig.2). Every time a new measurement is received, the application stores this value in an internal data structure and at the same time it displays a colour- encoded point at the exact longitude and latitude in the map. Colour depends on the CPS value. At the lower part of the application there is an information tab. Since the users spend most of the time on this screen, they need a way to know the overall status of the system. The summary part, which is available, contains the following:
– Three status icons corresponding to GPS, Bluetooth and radiation device connectivity. The first two are green when the connection is active, otherwise they are grey. The third one is animated like a heart pulse to indicate that the CPS storing and visualisation proceeds flawlessly.
– There is an additional icon in the tab that represents the method of the radiation mapping. Furthermore, there are two character stringsdisplaying information about the current CPS value and the visual colour-encoded CPS range.
There is a button in the navigation part of the screen, which contains a set of map related tasks. Using this button the user can clear and redraw the map. An additionally important task is the display of the map settings screen.
In the map settings screen the user can adjust various visualisation parameters (fig.3). Firstly, there is the option to select the radiation mapping which is used to perform the measurements. There are three methods available, measurements taken on foot, by UAV or using a car. According to the selection, the zoom level of the map is changed to allow a reasonable display detail level. Moreover, in this point an attenuation factor can be added since there is a different sensitivity level if the user takes measurements inside of a car or on foot. Secondly, the user can adjust the colour encoding of the measurements. More precisely, the red colour represents measurements close to 500 CPS and purple close 0. In cases where the area is considered safe the colour will remain purple without the ability to represent minor fluctuations of 10 to 20 CPS difference. Thus, in this screen the user is able to define the maximum CPS value and based on this value the CPS range is rescaled accordingly. As a result, with a maximum of 50 CPS the range of each colour will be approximately 7 instead of the initially 71 for the 500 CPS. All in all, when the user returns to the map the measurements are redrawn reflecting the new colour range.