Today saw the students spending another day in Mellieha correcting the epistemological and ontological issues of their data collection from the previous day. With a better understanding of landuse types, their equipment’s limitations and a common conceptual framework for conducting their mapping they produced a much better product.
The staff rewarded the students by saving them a significant amount of time at the end of the day aggregating their data – here’s a brief explanation.
Typically at the end of a day of mobile mapping using PDAs the students need to get together in their groups, download their data to a laptop and then spend a significant amount of time (in the past between 3-6 hours) collating and editing their data.
To change the focus of the task from data manipulation to examining the data collected KU GIS lecturers Dr Field & Dr O’Brien decided to implement some of the ESRI technology at our disposal while demonstrating to the students the changing trend from desktop to server in the GIS industry.
By implementing an ArcGIS Server on a Panasonic Toughbook laptop we could bring the server into the field with us and using a mobile wireless router students could connect to it anyway (providing they were in range of the WIFI). As a side note we could have done this using a 3G data connection but roaming costs in Malta are astronomical.
What’s the advantage of this? Well the Server is running a spatial database that supports versioning of data. That means that when uploads of the same data take place they are tagged with a username, date and time so that “good” data from one student group can supercede “bad” data from another group. This database also provides a place for all of the data to be uploaded.
By making this server mobile and accessible via WIFI students don’t need to cluster around laptops. Instead (as we did tonight) they can sit on the roof of the hotel within range of the WIFI network and simultaneously upload their data to the server which will collate it and if necessary stream it back to the students so they can all have an up-to-date copy on their PDAs. This evening it took longer to explain the process to the students than it did to synchronise the PDAs and collect the data on the server. Within 5 minutes of the process starting the students were able to view the data within ArcCatalog on the screen.
The students could then have started their laptops, connected to ArcGIS Server using the desktop ArcGIS client and downloaded the data for further analysis.
Future developments of this (3G roaming charges permitting) would have the students regularly uploading data to the server during the day and sharing it with staff and other groups. This enables students to see each other’s progress, for staff to keep an eye on areas of interest that are being missed, student groups locations to be monitored and data quality to be checked (e.g. if staff know the landcover of a particular area and it’s incorrectly tagged this can be corrected while the group is still in the field).
This development is novel as servers are traditionally located in secure, temperature controlled environments – not the rooftops of Mediterranean hotels (or anywhere else the staff need to set it up). Students have traditionally spent a significant amount of time engaging in menial data aggregation tasks to the detriment of the more important data analysis tasks (a problem that no longer exists). Instead the students can focus on analysing the level of agricultural change which is the focus of this exercise.