Lab Five: Introduction to Arc Collector

Objective:

To use arc collector to collect data with the use of a mobile device running on IOS or Android. This lab introduces students to the creation of a web map to be shared across ArcGIS with Arc Collector. Students then are tasked to collect more micro climate with the use of Kestral wind gauges in the same fashion as the previous lab.

Methods: 

Figure 1. Classmate Audrey Bottolfson poses with an Arc Collector enabled smart phone and Kestrel wind gauge.

For the first step of this project the same feature class used in the previous lab was made available for use in this one. No changes were made to domains or coded index items as it was warmer this day (March 8^th, 2016) and adjustments were unnecessary.

This feature class was then deployed to ArcGIS Online with an accompanying base map, making it ready for collecting data with a mobile device through ESRI’s Arc Collector mobile application. As with a great deal of equipment initially it didn’t work, but after intensive troubleshooting by the course instructor it became functional.

As like the previous lab, microclimate measurements were taken with the use of a Kestral wind gauge. These readings were then entered as data points into the feature class via the use of a personal mobile device. After about 45 minutes of data collection the entire class reconvened to upload the data into a shared drive for all to access.

Results: 

Figure 2. Compiled temperature readings across the UWEC campus (five category Jenks natural breaks classification). 

While collecting data it was obvious that the locations recorded by the mobile devices were not as accurate as those recorded by the dedicated GPS devices used for the previous lab. There were several instances where the recorded point was off by tens of meters even after allowing the device to focus in on a stationary location. Data entry on the mobile device was far easier to use than with the dedicated Juno GPS due to the far more intuitive and user friendly design of the smartphone and the collector app. In my opinion the relative poor accuracy of my mobile device compared to the Juno was not a bad compromise for the ease of data entry. There is also the advantage of the data being uploaded automatically to ArcGIS Online as data connections become available, meaning that data is rarely lost and available for viewing and editing from remote locations almost immediately. 

Figure 3. Screen shot of user interface of Arc Collector. 

This lack of accuracy led to several issues when combining data with the other members of my class. For instance, not all mobile devices are built using the same GPS receiver meaning that some are far more accurate than others. The GPS receiver in my mobile device was accurate within about 20 meters. In figure three this lack of positional accuracy was apparent while collecting data. The GPS said that it was located at the blue and white arrow dot in the center of the image. My real location was actually at the northern green dot to the left of the blue one. A classmate’s device was newer and was more accurate than mine; within about 15 meters. This difference in spatial accuracy across devices does not help the data’s integrity as a whole, but for this project it isn’t very important as locational accuracy is not the focus for the exercise.

Conclusion:

Microclimate data collection via Arc Collector is far superior to using a GPS in how it is convenient and able to compute and update data quickly. The time it takes most mobile devices to acquire satellite signals is far quicker than a good majority of commercial GPS units. The drawbacks for this tool in collecting data is that the locational accuracy is not quite comparable to a modern designated GPS unit and some mobile devices use better GPS receivers in their construction than others which makes them more accurate than their counterparts. But this is often not a problem for data collection that doesn’t require specific precision.