QGIS v ArcGIS

I’ve studied GIS for over 15yrs and been involved in testing (functionality & stability) of both systems for corporate entities and have found both systems to have little “niggles”, mostly noticeable due to the years of using both software. So, to the developers, this is my list of things I would like fixed….to the new users, this is my personal view of how the software compares (but remember these are MINOR niggles)….and to the other users out there I am interested to hear how you feel or whether I am alone in this.

1. Price

QGIS is an Open Source (Free subject to GNU license conditions) Geographic Information System that works on almost all operating systems and comes out of the box with a desktop application. There is also mobile & web versions which can be installed.

ArcGIS from ESRI is a proprietary GIS which offers a free 60 day free trial and also a free viewer (subject to license). The ArcGIS system comes in several different “Models” depending on the expected use, these are Basic, Standard & Advanced. Pricing is based on this core system choice & then any “Extensions” to this system, for example 3D capability, spatial analysis tools , tracking analyst tools – (see more here). ESRI also provide as part of the system access to their ArcGIS Online & a huge repository of data which can be used under the ESRI license. Further purchase allows web & mobile capability.

2. Interface

QGIS: 

Those familiar with a GIS will imidiately recognise basic functions such as adding layers, measuring, identifying & selecting. As with other GIS, there are a multitude of “other buttons” which provide further functionality & can sometimes be daunting but all toolbars are dockable & it is extremely easy to set the interdace and functions as you like it.

From a GIS professionals point of view, the coordinate system feedback is a little clumsy or rather, invisible…when changing between coordinate systems there are few options for changing information or ensuring the correct system is being used. Furthermore when setting coordinate systems for data frames there is little control for setting individual transformations for items & the interface does not show enough detail on the coordinate system being chosen (which false eastings/northings does the selected system use? etc)

In contrast QGIS makes using different data formats a breeze, ENC data, shapefile data, PostGIS or even fgb amongst a few are easy to consume and draw up. It is clear and easy to see which formats can ber accessed from which point and also where they are layered. Symbolising the data is a cartographers dream with more options than you could ever use, turning simple maps into works of art.

QGIS allows map production through another window which is almost like opening another add-on software called “Print Composer” although this is quite different and seemingly unnecessary to begin with, after a few weeks of use the extra functionality and the fact that it runs in a separate window is a blessing, providing some really nice capability.

ArcGIS:

 Out of the box there is a certain familiarity to ArcGIS, there are all the tools you would expect but it all has a slight 1990s “technical software” feel about it, though again, as with QGIS, there is hundreds of strange buttons and frames

Rather that starting with an empty screen, ArcGIS loads previous projects and shows you a selection to choose from on load (see below for more detail) – to the new user, this could be quite confusing.

With ArcGIS 9.3, ESRI integrated the data browser (know as ArcCatalog) into the software so that you can “Google Search” for your data from you local file server which makes for finding data extremely easy.

Adding new data (not through the browser) can be confusing initially, I remember in the early days spending 5mins every data looking for the “add data”. Once in, trying to add data is a little technical due to having to “set” the folders you want to access data from. If you get over these initial hurdles there are lots, if not hundreds of symbology options which allow you to render you maps with style. The one thing I will say here is that you can’t help but be a little disappointed if going from QGIS to ArcGIS as the ArcGIS uses fonts as its base for many of its symbols & there are few options for where layers conflict or using your own created symbols.

Map production is simple with ArcGIS and utilises the map frame to display the map output. Creating templates and defining boxes and labels is very easy and intuitive. Again, as with other areas of the ArcGIS system, options are hidden behind other options which are behind further options which can be confusing for the uninitiated but once used for a few weeks are quite logical.

Where ArcGIS shines from a GIS professionals point of view is that coordinate system interface. When using conflicting datum there is clear questions raised over how this should be dealt with through use of drop-downs with options for transformations.Furthermore at anytime you can select a layer or map frame to see detail on the coordinate system being used. Where the necessary coordinate system isn’t available or where some customisation is require, the interface for adjusting the datum is very simple to even the novice with further options to set favourite coordinate systems or frequently used coordinate systems.

Load time:

Authors note  – this shouldn’t really be a subsection, instead discussion should be on features/extras/stability but it is such a discussed issue that it had to be noted.

QGIS:

 Loads like most other software (MS Word, Excel, Photoshop etc) the only niggle is the “did you know” pop up which appears to give advise on the software….okay, this can be removed after the first use but be warned if using a dualscreen set up and it can disappear & you find yourself wondering why you can’t add your data!

ArcGIS: 

As stated above, it is great that on start up it provides you with a few of your recent projects to work with through an initial splashscreen. Only to do this, ArcGIS has to read all those folders which you connected (see adding layers in ArcGIS above) to find and verify the data before the screen shows. If, like many GIS professionals, you have hundreds of projects running in multiple locations, it can take a fair while to get started. To many new users it is a bit of a gripe as it makes the system seem a little slow and clunky.

Extras:

QGIS: 

Out of the box there is basic spatial analysis functionality & statistical analysis available. There is also a large geoprocessing toolbox which utilises many of the tools & functions from other software such as GRASS, SAGA and R to allow complex tasks and also build flowcharts (called geoprocessing workflows) where many tools can be linked together to automate things.

1.    Like ArcGIS, QGIS also has “plug-ins”, with QGIS these are built by both developer and user alike which means that some are nothing more than shortcuts but as a whole many of the plug-ins provide the professional with tools such as (here is a small sample of the hundred plus FREE plug-ins):

2.    QGIS2Threejs -Provides 3D rendering & sharing capability through webGL, allowing provision of interactive 3D models via the web brower

3.    OpenLayers Plugin – Open Streetmap, Bing, Google & Stamen basemaps available at no cost to use under your data

4.    CADTools – Allows survey style & technical editing with chamfer, parallel & offset editing options

5.    Profile Tool – If you have a DEM or DSM as a layer, you can simply draw a line anywhere to extract the profile of the surface as an image or in graph format.

6.    Ordnance Survey Translator – Converts Ordnance Survey GML format data to any other (OGR) geospatial format

7.    OpenGeo – Allows WYSIWYG mapping and load to the (open source) OpenGeo web mapping system.

8.    A model created with the QGIS2Threejs plugin

9.    Through update on the OSGEO4W site, WMS/WFS data can be served directly from QGIS (QGIS Server) to your web map service and is, again, WYSIWYG. Then, if you are using the Ubuntu operating system, you can add the QGIS Web Client to enable full web mapping with tools direct from your QGIS desktop.

1  QGIS has a large community of developers and supporters with a multitude of backgrounds & this really helps when you come across a problem, issue or analysis which QGIS might not support. Sometimes a developer can see how useful it will be to the software to include the tool or process & it can be up in the “Master” (the working development build which is available to download) within hours OR you could pay someone a small fee for helping out (more like a donation than a fee) to help develop your tool (I’ve normally paid between £50-150) OR there is huge support on GIS StackExchange, where you could get immediate help from the wider GIS community.

11.  The only thing to note is that unless you opt for commercial support (which is VERY cheap), you are relying on the good will of volunteers who are extremely passionate about the software, so sometimes when you have a tight deadline and it is all falling down around you, you don’t have that safety net…..though if you need that, purchase some commercial support!

ArcGIS: 

Depending on the package you chose (See pricing above), will depend on the amount of extras and functionality you have out of the box. To be comparable in this instance, I will base my view from the “basic” package.

1.    The basic package, although sounding relatively low on features has quite a few tools. There are 100+ geoprocessing tools & also advanced editing options. What is obvious though is that even with the basic package, there is integration with the ArcGIS Online facility whereby you can access hundreds of data from detailed basemaps to user created data (including some government data such as census & crime).

2.    To better perform analysis in your area of work, ESRI provide many extensions (at cost) to the ArcGIS suite, some of which are listed here:

3.    ArcGIS 3D Analyst – A full suite of tools for manipulation and display of 3D data including creation of surfaces, DEM. DSM, TINs, 3D analysis (3D buffers, line of sight etc) & also access

4.    ArcGIS Geostatistical Analyst – Allows you to model, simulate & evaluate statistical data related to your geodata

5.    ArcGIS Network Analyst – Provides network-based spatial analysis tools for solving routing problems. –

6.  ArcGIS Tracking Analyst – Extends the time-aware capabilities of the ArcGIS system with advanced functions to let you view, analyze, and understand spatial patterns and trends in the context of time.

7.    ArcGIS Data Interoperability – Gives more data formats for ArcGIS to use

8.    Modelling 3D cities using ESRI Extension CityEngine

9.    ESRI sells the ArcGIS for Server which “bolts on” to the ArcGIS Suite to provide full web map capability in a WYSIWYG environment. Originally you needed to be quite technical to use this extension but thanks to the hard work of the ESRI development team, there is now a simple button “Send to web”, the Server system also supports provision of WMS/WFS/WCS formats. For those who don’t wish to commit to such a system, there is the ArcGIS Online (at an additional cost) which provides a web mapping capability without the need for a server, the online maps are held on the “GIS Cloud” (ESRIs Servers). Again, this is very simple and data can simply be uploaded to the ArcGIS Online direct from the desktop, with this service the price is based on amount of consumption rather than a fixed cost like the other extensions.

ESRI, for a fee, provide dedicated support 24/7. Having had experience with calling about transformation issues & speed issues, they are very hit & miss, rarely have I had a bug fix or work around the same day but that said they are very helpful & try their best.

Development

QGIS: 

Has a core team of developers who concentrate on the software improvement & there are commercial companies who offer tools and software development at cost. Further to all this, QGIS utilises Python for it’s tool development and has an extensive library of documentation and an online community where help can be obtained.

Being a born “Tinkerer” I have found it not too complicated when push comes to shove, to get into the gubbins and make adjustments, for example adding a geoprocess or changing a coordinate system reference. Where this is built in a modular fashion with open standards (its designed for this type of “tinkering”), it is easy to set right when you make a mistake.

ArcGIS: 

Development is led by the ESRI development team and commercially led. This is not to say that there isn’t an opportunity for development….many of the new functionality within ArcGIS has come from user feedback and issues, also for cost ESRI is able to develop $$ anything you can dream of.

Like QGIS, the software utilises Python for build of geoprocessing tools and where the software is so huge, it can be quite daunting to get your head around how to call all the necessary components, though there is a wealth of information on the extensive ESRI training but I highly recommend getting some training.

Understandably the software is quite closed so tinkering isn’t so easy though you have support if you do make too much of a mess.

Speed

QGIS: 

Here is where comparisons start to get a little tricky and keep in mind that I am writing this based on QGIS 2.6.1 & ArcGIS 10.2….QGIS runs as 64bit software, it utilises more than one core at a time for processing and it is noticeable. Working with raster data is a little faster than vector data but marginally. Working between different data formats shows no speed issues, the main issues arise when you are using data 4GB and above as you require the available memory to process and serve.

ArcGIS: 

As I write this ArcGIS works as a 32bit application, this means that it only utilises one core at any time and will use the RAM contiguously….but interestingly I have found that it will use well above the Windows recommended maximum RAM. In theory, 32bit Windows has a 4GB limit on RAM but ArcGIS will still consume RAM well over this – I currently use a machine with 16GB of RAM and find ArcGIS using it up!

Niggles & Life saversQGIS:

Niggles

Although shadows are available for fonts, there is no option for point symbols.

Plug-in/Add-on documentation – There is a huge list of amazing plugins but little or no information on what they do or how to use them.

Annotation/Text labels are difficult to control, although there are many, many options, there are none to keep the labels a minimum distance (like a buffer) from each other OR an option to convert them to free labels in the map so that they can be moved freely using the mouse,

Personally, when I categorise data, I’d like to do it on multiple fields like NAME & CITY or STREET & TOWN.

Metadata – There doesn’t appear to be a way to read or write metadata to any of the required standards.

Table joins are not as obvious and easy as in ArcGIS.

Life Savers

Cartography is a synch with some beautiful and clever options which allow artistic maps.

The options for editing the legend of a map is amazing. You can alter layer names without ever needing to alter the layer name, you can adjust the legend layer order without adjusting map layers, there are also options to further add group titles and subgroup titles for any or all layers without affecting the map.

Consuming data – when all other GIS have you beating your head against the wall, you can guarantee that you can bring it into QGIS!

ArcGIS:

Niggles

The symbol options are dated, mostly font based when many other GIS are providing more image & stylised options.

Although ArcGIS has many geospatial data formats it is able to use and write to, it is also very closed and predominantly uses the ESRI formats. In an age where the market is saturated with data it is frustrating to not be able to use PostGIS, ENC, RNC or raw LiDAR data in the basic version.

Why do I have to turn off the editing to calculate a field?!

Life Savers

Categorising and rendering statistical data based on multiple fields is easy, VERY easy.

Table Joins & Relates Wow! It is so good that when I work on statistical data in Excel I often find myself joining the tables (even when non spatial) in ArcGIS!!

There are so many options when it comes to labelling that you can always get the desired result and when you can’t, you can convert the labels to graphic text and move it by hand!!

 Conclusion?

They are both great GIS