Lab 7: Arc Collector

An Introduction to gathering geospatial data on a mobile device, such as a tablet or smartphone

Introduction

Since most people always have a smart phone or tablet on them at all times, using these devices to collect spatial data can be very easy and effective. This lab is an introduction to gathering geospatial data on a mobile device using the App Arc Collector. On October 24, 2017 teams were sent out across the UWEC campus to collect weather data such as wind speed, temperature, dew point, and others. Using ArcCollector, all data was collected with a specific geographic point on campus.

Study Area

Data was collected on the UWEC campus. As shown in Figure 1, the campus was divided into zones. Teams of 2-4 students were sent to each zone. 

Figure 1: Study Area Map

Methods

Dr. Hupy created the private group "Geog336Micro_Section01" on ArcGIS online as well as a survey for the App ArcCollector. This App is described in Lab 5: Using a Bluetooth GPS with an iOS Device. Students downloaded ArcCollector, logged onto ArcGIS online group "Geog336Micro_Section01" to access the survey. 

Students were divided into groups of 2-4 and sent out into different zones on campus to collect weather data in their zone. Criteria collected included Temperature (Degrees Fahrenheit), Dew Point (Degrees Celsius), Wind Chill (Degrees Fahrenheit), Wind Speed (Miles per Hour), and Wind Direction (Azimuth). The first four pieces of data were collected with the Kestrel 3000, as pictured in figure 2. Wind Direction was collected with a flag and Geographer's Compass, pictured in figure 3.

Figure 2: Kestrel 3000

Figure 3: Geographers Compass

Using ArcCollector is fairly simple. Figure 4 shows the map screen, used to determine geographic location. The green dots indicate points where data has been collected and the larger grey dot indicates the current location. To add a data point click the plus sign on the bottom ribbon. This will open the survey screen, figure 5. Using the phone's GPS, the location is automatically recorded. The user must then complete the survey. There was a preset range of inputs to be selected for each field. Once all the fields are completed, click the check mark on the upper ribbon to upload the data. Data is added to the map in real time as it is collected.

Figure 4: ArcCollector Map Screen. Green dots are collected points. Larger grey dot is current location. Plus sign on the bottom ribbon opens the survey pages.

Figure 5: ArcCollector Survey Page. Fill out each field at each location, click the check mark to confirm and upload data to map. 

Once all the data is collected, it can be downloaded from ArcGIS online and represented in ArcMap.

Discussion

Temperature

The lowest temperature values collected on this day are those collected nearest the river. 

Figure 6: Temperature Map

Wind Chill

Wind chill temperatures are coldest near the river where the temperatures are lower and wind speeds are the greatest. 

Figure 7: Wind Chill Temperatures Map

Dew Point

Dew point is the atmospheric temperature below which water droplets begin to condense and dew can form. Dew point varies according to pressure and humidity. Dew point appears to be greatest near the river on the eastern end of zone two. 

Figure 8: Dew Point Map

Wind Speed and Direction

Wind speeds tend to be greater closer to the river. Visually, wind direction trends to the northwest. Statistically, the mean azimuth is 228 degrees, which is to the southwest. However, when looking at the frequency distribution, most values are greater than 250 degrees. The scattering of azimuths collected less than 250 degrees could be due to eddy currents generated as the wind flows around a building.

Figure 9: Wind Speed and Direction Map

Figure 10: Wind Direction Statistics

Conclusions

The lab effectively demonstrated the simplicity of using ArcCollector on mobile devices to collect geospatial data. The smartphone GPS was accurate enough to pinpoint locations, and the survey was simple to fill out and upload. Data was displayed in real time even as data was collected from multiple devices simultaneously.