IS428 AY2019-20T1 Assign Christine Anomalies Observation

VISUALIZATION OF ALWAYS SAFE NUCLEAR POWER PLANT

PROBLEM & MOTIVATION

DATA ANALYSIS & TRANSFORMATION

INTERACTIVE VISUALIZATION

ANOMALIES OBSERVATION

REFERENCE

Q1. Visualize radiation measurements over time from both static and mobile sensors to identify areas where radiation over background is detected. Characterize changes over time.

STATIC SENSOR READINGS

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  Figure 1.1 - Static Sensor’s readings over time period

In terms of radiation level, healthy reading level was set at 75cpm (Watts, A. et al., 2011), when any sensor readings that exceed this healthy level; attention need to be given to the respective sensor before it reaches warning level at 100cpm. Based on the readings, before 8 April 2020 03:00PM, radiation level shows minor fluctuation (relatively stable in terms of changes in reading); however, after 8 April 2020 03:00PM, there are significant spikes of radiation readings spotted across all sensors but especially sensor 12-JadeBridge, 13-SafeTown, 14-CheddarFord, and 15-SafeTown_Nuclear have the noisiest spikes among other sensors on this day. This was possibly due to these sensors are located nearest to the power plant especially sensor 13-SafeTown and 15-SafeTown_Nuclear located in the region of Safe Town – location of Always Safe Nuclear power plant. So that when earthquake is happening, those sensors are affected the most.

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  Figure 1.2 - Static Sensor readings at location on map
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  Figure 1.3 - Cumulative sum of static sensor’s readings

Additionally, from Cumulative Sum of radiation readings, we can clearly identify the first few sensors that show abnormal spikes in radiation readings are sensor 12-JadeBridge at 8 April 2020 3:00PM and 15-Safe Town_Nuclear at 8 April 2020 4PM.

MOBILE SENSOR READINGS

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  Figure 1.4 - Static sensor 10 – 14 readings and trails of sensor 10 & 12
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  Figure 1.5 - Cumulative sum of mobile sensor’s readings

As compared to static sensor, mobile sensor HSS(10-Mobile) show high spike above healthy level (75cpm) between 8 April 2020 4:37PM until 10:00PM where at this period the sensor’s trail passed Jade Bridge (Green box on Figure 1.4) and based on Figure 1.5, HSS(10-Mobile) is the first sensor that show high spike of radiation reading. Aside from HSS (10-Mobile), there is another sensor that pass Jade Bridge at this period, CitizenScientist(12-Mobile) also show similar pattern in radiation readings which shows that there are contaminations at Jade Bridge. On top of that, CitizenScientist(12-Mobile) show short period highest spike of radiation reading on 9 April 2020 02:43AM (Green box on Figure 1.4). Aside from these findings, both HSS(10-Mobile) and CitizenScientist(12-Mobile) located at Old Town, then travelled to Jade Bridge and surrounding. At the end of readings, both sensors come back to Old Town; this suggest that there are contaminations at Jade Bridge.

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  Figure 1.6 – Readings of Mobile Sensor 21, 25, & 29 and location on map

However, on 9 April 2020 08:02PM; readings show high readings for CitizenScientist(21-Mobile), CitizenScientist(25-Mobile), and AS-2(29-Mobile) with AS-2(29-Mobile) is the highest; but after 10 April 2020 06:35:35PM, all three sensors’ readings are starting to disappear sequentially from AS-2(29-Mobile), CitizenScientist(25-Mobile), and CitizenScientist(21-Mobile).

Q2. Use visual analytics to represent and analyze uncertainty in the measurement of radiation across the city.

Q2a. Compare uncertainty of the static sensors to the mobile sensors. What anomalies can you see? Are there sensors that are too uncertain to trust?

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  Figure 2.1 – Radiation readings of Static Sensor
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  Figure 2.2 – Cumulative sum of static sensor’s readings