High school students in Port Colborne, Ontario, learned how to create a map using a Trimble Catalyst DA1 GNSS receiver.
As a teacher who believes in preparing his students for the real world, Fletcher wanted his students to get hands-on experience with on-site surveying and in-class cartography. They already had a fully dedicated GIS lab equipped with refurbished computer equipment and donated software but were lacking the GNSS equipment necessary for high-accuracy data collection.
Jonathan Fletcher’s geography students get hands-on experience in a dedicated GIS lab.
Fletcher first learned about the Trimble Catalyst positioning service with DA1 GNSS receiver in 2017 at the Esri User Conference. The high precision digital antenna housed inside the affordable receiver allows GNSS signals and satellite corrections to be passed to the Trimble Catalyst app running on an Android smartphone or tablet. The lightweight, easy-to-use device seemed like a good fit for the practical instruction he likes to provide to students.
“I immediately thought of some useful applications for this receiver in my classroom,” says Fletcher. “When the opportunity arose to help DSBN and teach my students at the same time, I put in a request for a Trimble Catalyst system. Working with real equipment has increased student engagement in geography class, leading to my students winning the gold medal in the Ontario Technological Skills Competition every year since 2017.”
In Spring 2019, Fletcher received approval to purchase one Trimble Catalyst DA1 GNSS receiver. Thanks to the generosity of parents and local geospatial businesses, donations of cash and used equipment provided Fletcher with three more GNSS receivers, four survey poles and four Android cell phones. Local Trimble distributor Cansel offered four three-month subscriptions for the Catalyst Precision service at no charge. On its own, a Trimble Catalyst receiver gets 1-m accuracy and with the Catalyst Precision service it can return data with 2–4 cm accuracy.
Students recorded all park assets using the Catalyst DA1.
Integrated Software and Hardware
Using Esri’s ArcGIS® Survey123 software, Fletcher created a survey of the information needed for the project and added this layer as an empty feature service to an ArcGIS Online map, which was then downloaded into Esri® Collector for ArcGIS on the phone so data could be collected offline. An empty feature service provides a framework for Trimble Catalyst to talk to ArcGIS Online.
The 20 students were broken into four groups. To start collecting data, they connected the Android phones to the Catalyst antennae, put the phones in Developer Mode and selected settings on the phones to indicate current location, height of antenna and desired accuracy. They recorded all park assets in the outdoor center, including buildings, bridges, stairs, signs, boardwalks and trails (points were placed every 15–20 meters and at every turn).
“After a bit of trial and error, we settled on 40-cm accuracy to speed up the data collection,” explained Fletcher. “On our second visit to the center we had a much more refined and efficient method. We were able to correct some of the sign and asset data, as well as collect the points for another trail that the Center uses in Short Hills Provincial Park.”
The students uploaded data into ArcGIS Online and downloaded to ArcGIS Desktop where data was cleaned and prepared for the creation of maps. Using Esri ArcMap® 10.6, they connected the dots of the waypoints and drew in the trails, assets, and signs. They produced poster-sized maps of the entire site and of the buildings, and letter-sized maps of the entire site and each of the three trails.
The finished maps are used by staff and visitors at the DSBN outdoor education center.
After successfully producing maps based on accurate location data collected with the Trimble Catalyst DA1 GNSS receivers, the class presented the finished product to 1,100 GIS professionals at Esri Canada’s User Conference in 2019. Today the maps are used daily by staff and visitors at the outdoor education center.
“Without Catalyst, we wouldn’t have been able to collect data at our desired accuracy—GPS on a cell phone only has six-meter accuracy, which is not good enough to give emergency services the exact location they need,” Fletcher said. “This project helped the students understand how GIS concepts apply to the real world and why accuracy is so important in the end product.
“The Catalyst was perfect for our project. It delivered the accuracy we needed in less time than a total station, and the price was right. My students are very familiar with Esri apps on their cell phones, so they were quick to learn the process of collecting data.”
— Jonathan Fletcher, geography teacher at Port Colborne High School, Port Colborne, Ontario