PocketGIS

PocketGIS v2.0.7

The council I work for has just invested in this software to enable data capture in the field. Its essentially an interactive map (or set of maps) that you can edit. For me that means plotting trees for development sites or for surveying TPOs, but the applications go well past that.

I won’t bore you with the intricacies behind GIS (Geographical Information Systems) but I will explain briefly just to make a few points.

Basically most GIS consist of maps made up of layers. These layers have various bits of information on them and they overlap to, allow you to see the realtionship between points lines or areas.

For example, our GIS looks a bit like this (working from top to bottom)

1. Tree layer – editable layer where trees are plotted.
2. TPOs – Circles and polygons showing our existing TPOs with date and ref no.
3. Conservation Areas – Translucent green polygons showing conservation areas
4. Parish Wards – lines showing the parish boundaries
5. Base Map – Buildings, roads, rivers you get the idea

You can turn these layers on and off as you like.

The software works in two parts – one for the handheld machine an one for your main pc which does all the hard work.

Anyway, now that exceedingly brief introduction is complete (and its worth noting that I have glossed over a lot of complicated information) we can move on to the review!

I’m going to break this up into three basic parts:-

1. Setting the software up
2. Using it in the field
3. Getting useful results from your data

1.Setting the software up –

Lets face it, we want to stick trees on a map and record some information about them. So with PocketGIS we have to tell it what data we want, e.g., Tree number / species / dbh…

This is quite a flexible system but you’re right in the raw structure of the software, no wizards or step-by-step procedures. I had a 2 weeks of trial and error, creating the capture layer, putting it on the handheld mapper, trying it out and changing a bit…

Once you learn the lingo and understand the mechanism behind everything it a bit quicker.

PocketGIS cannot do calculations, so no RPA / QTRA / Hazard calcs, which is a big let down IMO.

On the plus side the dealer support has been good, and my long and dull questions rapidly and in detail.

2. Using it in the field –

This depends on the machine that you’re running it on, and how you’ve set it up!

I’ve run this on the aforementioned mobilemapper and also trialled it on my Orange SPV M600 (running windows mobile 2000). Some of options are not available on different operating systems – so running it on windows CE allows you to break the data capture questions into seperate pages. Windows mobile 2000 does not. This has implications for how you use it, as you may want to simplify the data on a mobile 2000 device.

There is an issue with positioning accuracy. Its only as good as you are! We run base maps supplied by the OS and I’ve stumbled into many boundary issues.
The units we mainly have this installed on are Magellen MobileMappers which have a built in GPS. The GPS function allows you to pinpoint your location to facilitate data capture.
The GPS has its own issues but this is a review of the software and not the machine so I’ll cut it short there!

Data capture is fairly straightforward. Select the feature you want to add to the layer. Tap the location and add the info. You’re only limited by how you’ve set the software up! After a few days out in the field, I could capture 40 odd trees in an hour (just tree number and species).

3. Getting useful results from your data

This depends on what you want to do. Let’s assume you’ll want a map and a table of tree info. To get a decent map you’ll need more advanced software (PocketGIS does allow printing but the interface is limited) such as AutoCAD, Cadcorp, MapInfo or Arcview. These systems are disgustingly expensive. Bit of a problem for the home user…
Generating a table is easier as PocketGIS will export your data to a .csv file which can be read by pretty much anything.

Single license will set you back about £800.

On balance – I like it. Its a shame that it can’t execute calculations and its tough to learn the lingo, but the support from the dealer was good. At one point I simply emailed my messy files to them and they sorted them out form me! Its flexibilty is daunting at first but after a while you begin to see the possibilities.

However, its a small part of a big spend considering that you’ll need a PC / Mapping software (to get the best out of it) / GPS. If you just do the occasional survey this might be too much.

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