Sunday, March 13, 2016

Another Cheap way to bring your maps to the field (Geospatial Portable Document Format)

Nowadays, bringing maps to the field is not as complex/expensive as in the past. There are numerous software and tools that could be utilized to do that. A range of IOS/Android/Windows phone gadgets can do it using various methods either online or offline then synchronize all the fieldwork to the source data back in the office.

But people usually looking for simple and cheap way no matter what is the purpose to do the fieldworks. Am I right ? so if you are one of them (like me too), I will give some insight that may  could be useful.

PDF format since few years ago has been incorporated geospatial information as part of the auxiliary information stored in the file. This cool feature enabling us to save a map in PDF format (include its geospatial coordinates) and then transfer it to our phones and brings it to the field to do field check (integrated with our phones GPS Capabilities). This method sure saving us more resources instead of field online mapping (in aspect of carrier data charge, battery power, gadget storage capacity, rendering performance etc). Furthermore, PDF is well known for great compression rate so a satellite imagery in 6GB size could be stored just for 400 MB size.

One of mobile tools that can read geospatial PDF is  Avenza PDF maps that you can download for free from Google Play Store . This tool also support import/export KML file if you want to overlaying vector maps or generate vector data (includes its attribute table could you designed directly) in the field, either using waypoint marking or line tracking (using phones built in GPS receiver). Here is below a screenshot of what I just test. Saving a my country official topographic map in geospatial PDF and bring it to the field. Using this method I could bring old maps to the field to do change detection field inspecting without needs to host it to online GIS Server.

And then, what software can be used to write Geospatial PDF from geospatial data ? well, you could use TerraGO, ArcGIS, Global Mapper to do it. And from the Open source/freeware side, QGIS could also make it with some efforts.

Suddenly I remember when  I was still in my second semester at college. Doing fieldwork check for Map Use Course, brings A1 size printed topographic map to the field, sweep away the map with the help of some friends, using stones to hold it so the wind cant slam it. Such a great and tedious times.

A lot of things has changed since then.....