This is part 2 of a discussion on mobile GIS and feature editing. In part 1 we began the discussion. Here we spoke about saving basemap tiles and shapefiles to the mobile device. How shapefiles can be represented (overlaid) on the map in a number of, less than perfect, ways. We discussed other mobile GIS type apps which load shapefiles. We have actually just created a video which compares a number of these mobile GIS apps, with a focus on shapefile and attribute query. In this article we will take this discussion further and look at possible solutions
Online/Offline Mobile GIS Feature Editing
There are a number of approaches which can be taken when looking at solutions for online and offline feature editing and data recording:
- Using the feature layer in ArcGIS – Discussed in this link from ESRI iOS ArcGIS Feature Editing
- Writing feature changes and attribute updates to local files on the mobile device (shown below)
Mobile GIS Feature Editing Demo & Local Files
The link below shows a demo of a mobile ArcGIS app showing feature editing on a Samsung mobile smartphone.
We have discussed in other blog posts how pen and paper are still widely used in the field for recording new and updating existing data respectively. We know ESRI are working on solutions to both viewing layers and editing features in both online and offline modes. The feature layer – ESRI’s equivalent to WFS – approach linked to above is just for the iOS platform. So far we see no cross platform or Android specific mobile ArcGIS solutions. We’ve asked (weeks ago) and still await a reply. The approach allows online/offline feature updating then auto ArcGIS server syncing. We presume the final commit to ArcGIS would be done by a GIS administrator, so no direct update from the field.
But what do you do if you have an old version of ArcGIS server, don’t have feature layers or are using an open source solution?
Solution 2 above, using local files to record data, is a simple and robust solution. This approach is simple, and does not tie you to the latest ArcGIS server release. The video above shows two types of updates. First updating a features geometry. Imagine a pipeline layer which, in sections, is inaccurately represented. Using a markup tool as shown allows users in the field to redraw these sections. This markup is stored in a file and can be loaded by a GIS administrator for a sanity check and GIS update. The markup tool could also be used for adding new features; maybe a new section of pipeline. Second there is updating a features attributes. Loading a locally stored shapefile, editing a features attributes from this shapefile, storing these changes in a local file and sending this to the GIS administrator, again for GIS update.
We are actively looking at building GeoMobile for Geoserver (we already have released GeoMobile for ArcGIS), an open source mobile GIS viewer. Feature editing as described above will be an important consideration.
We’d be interested in any feedback you might have on this article. We have received many inquiries about online and offline data collection and editing functionality. Have you taken one of these approaches, or something different? Is this an area you too are looking for a solution? Tell us more