Offline mapping provides a way to collect data in the field without an internet connection.  In this post we look at how an app is being used to collect dragonfly observations in Vanuatu.

Tramea transmarina – image courtesy of Milen Marinov

Several years back, Milen Marinov was working on his masters degree here.  He’s an expert on Odonata species (dragonflies) and as part of that research developed some maps of potential habitat for a number of species across New Zealand – you can find the map here.

Ah, now that brings back some memories – this was the very first webmap that we offered out to the world back in 2009.  Milen is still very much involved with dragonflies and we are currently at work creating a database of dragonfly observations across the Pacific.  He’s already collected a dizzying number of observations from literature but dragonflies have also transported him to some very exotic places (well, airplanes have).  This week he’s scheduled to go to Vanuatu to continue collecting data, so it seemed like a good time to “leverage” (as they so like to say in the GIS industry) the data and the capabilities of mapping.  But his trip poses some interesting challenges.

We’ve already got a webmap set up to share data between us – which is here:

This map is good for displaying that data so has been a useful resource for us working in two different places (he’s Auckland based).  But accessing this map depends on an internet connection, and most of the places where Milen’s planning on going will have neither WiFi nor a 3/4G connection.  So what to do?  Record coordinates with a GPS and map them later?  Or capture them as waypoints?  Annotate a map and digistise them later?  Well wouldn’t it be nice if he could collect his data in the field using a handheld device and then automatically have those data updated when he can get a connection later?  Say no more, say no more – all sorted, gov.  We’ve got just the app to make this work.

There were several steps in making this happen.  First, the existing point layer of observations was copied over to our GIS server (to our enterprise geodatabase to be exact).  Once in place there, the layer was translated into a map service so it could be used in a webmap.  When started, this service had some extra capabilities enabled, namely feature access.  The biggest difference between a map service with and without feature access is that a plain old map service delivers up and image of the data (as a JPG or PNG), not the actual data.  With a feature service, it’s like a portal has been opened up and someone on the web out there can have direct access to these data.  This means that the features can be added (or deleted) from this layer without even having ArcMap open, let alone installed.

So once the feature service is out there, it can be added to a new webmap –

Notice the Edit button – with this map data and attributes can be added, edited and deleted with any changes saved back to our server, so there is one source of truth for this layer.  Milen could use this straightaway for adding new observations – but this one absolutely requires an internet connection.  Instead, we’re going with an app that will work on a range of devices: ArcGIS Collector.  With this app and some judicious configurating, Milen can download the data and a basemap and use the device’s onboard GPS for locations.  He can create new data points and select from a preset list of species (which reduces the chances of typos and errors) as well as upload photos as attachments, all without an internet connection.  In the screenshot below you can see the map as it looks on the phone:

When he wants to record an observation he just presses the “+” and the next screen allows him to select the species from a list.  In the image below you can see some of those preset species – he can scroll up and down in this list to find the right one out of 31:

Then he can touch the screen where he wants to place the point or use the position from the GPS.  He can also snap a picture with the phone and attach it to that point.

Once back in range of an internet connection, he can sync up his collected points with the main data layer – no muss, no fuss.

The beauty of this should be pretty apparent, I hope.  Many people now have smartphones or tablets that they regularly take out in the field.  With this app (and the right data, of course), that device becomes a spatially enabled data logger (not quite a tricorder yet, but we’re getting there).  You can just hear that guy on the bus now, as he shares his conversation with everyone else, “No, really.  I’m mapping right now…!”

We’ll keep you posted on how Milen gets on in Vanuatu.  Even as we speak, Cyclone Donna is bearing down on northern Vanuatu, so we hope he doesn’t encounter any problems.  Since he no longer needs a spatial guy, maybe he’ll let me carry his bags…or dragonfly net (or brolly).

(Special thanks go to Ewan Dickie from Eagle Technology who helped us sort out some technical issues.  Ewan graduated from Lincoln last year and is now hard a work in the geospatial industry.)