For the last few years I have been in the search of a mobile app for data collection in the field –for earth-scientific purposes in specific-; Additionally, being able to ‘move with my existing cartographic information and navigating on it’ has been another subject to be addressed as a field geologist.
There are few solutions for such needs, which are not only (really) expensive but also impractical in my opinion. Thousands dollars priced ‘tough pad’ hardware coupled with external GPS’s (if not cost even more with a built-in sensor), running on ‘xxx pad’ version of software(s) of several hundred bucks license fee has never sounded feasible to me. Besides, the battery life limitations in addition to relatively chunky (minimum 10-11 inches) cases, notebook size power adaptor, etc. Last but not least, you need a good command of main stream GIS software to move your data into such portable systems without any glitch.
Well… I was not happy with any of these. I do not want to pull along a very valuable piece of fancy PC with a lot of dependent equipment, more importantly I do not want to lean on a GIS expert each time I want to move data back and forth.
So, what has changed? Recently I started using a mid-range, 7” size Android tablet powered by Map-It GIS app. How do I utilize such configuration for my professional needs? Long story short;
- By exporting virtually any kind of GIS data to mbtiles (raster) format to take them with me for either navigational purposes or using as a background map. Being able to switch across as many as mbtiles with few taps and simultaneous navigation on them… That is something on efficiency and accuracy.
- Collecting data of points, lines and polygons… Especially supervised point data collection, sampling stations, discontinuity measurements, observation points. As for line and polygon type data collection (geological unit contacts, structural elements, landslides etc.) further efforts needed on a desktop GIS system in order to finalize, but it is still very practical to outline non-point data.
- Eventually exporting all kind of collected data to kml and / or csv formats for further use. Simple and neat.
Where to start?
What is mbtile?
It is a raster file format for storing map tiles in a single file which technically is a SQLite database.
What is the trick?
No, real tricks actually. If you already use QGis then you have your styles, formatting and layout (all cartographical elements) are nicely in place and good looking. If so, you are lucky, just click to run QTiles plug-in and you have WYSIWYG.
But what if you work with other industry standard software, and cannot figure out exporting your map data within minutes with simple clicks? To be honest, I have no idea how production of mbtiles work in Esri or other software. Once I asked our GIS people at the company to provide me mbtiles from their fancy maps in ArcGis, but there many glitches at the time. So what did I do? I asked them to export a geotiff for me, and I used QGis and QTiles to export mbtiles. By the occasion it would be good to hear about Esri products and mbtiles generation, anyone has experience on that?
Once you produce mbtiles, copy the file to MapIt\OfflineMaps folder in the Android device and they are ready.
Next step, data collection by MapIt app:
As I mentioned above most acquired data type are point features. And the most efficient are supervised i.e. information consisting of a variety of choices to be picked from a previously defined list of attributes; Geological discontinuity data collection is a good example for this.
If you have properly designed feature attributes then you have efficiency (much faster than writing to elsewhere), consistency (no editorial differences across individuals who collect data) and more importantly accuracy (input fields are there and supervised, nothing to forget or mistaken).
What if you need to tailor a series of information to be defined as attributes? Thanks to MapIt, it has support for JSON format; you can use a text editor to create your attribute layout and easily import it to MapIt.
Some inspiration needed? Feel free to use these: GeoDataCollect_JSON
Below you will find some screenshot images on what is all this about.
I hope this post will give some inspiration to those who work in the field.
Stay well, stay inspired!