Please Note: Geometry IT is offering free copies of its iGIS app to reviewers. The author of this review has not participated in said opportunity and payed the full price for the iGIS software, unbeholden to anyone except his own recent “software review” addiction.
In December 2009, I upgraded to an iPhone. I quickly discovered the dark heart of commercialism which lurks at the heart of the Apple business model – location aware advertising, i.e. advertisements placed within free apps which target you based on your geographic location, a practice which has gotten so bad Apple is taking measures to curtail it. This is downright terrifying when you first notice it, despite the fact that all current generation cellphones are locatable for EMS purposes. Despite its faults, however, the iPhone and similar generation mobile phones have an enormous potential to substantially alter the way we work and play with GPS devices. To name but one example, there are a number of apps which compile position and velocity data for traffic monitoring purposes. These apps turn every iPhone into a probe vehicle, which is used to monitor traffic and provide realtime updates of traffic flows at virtually no cost, something DOT planners have previously spent millions to accomplish.
I have been particularly interested in altering my own iPhone to increase its GIS/GPS functionality. Put simply, the iPhone is a lot of hardware for a very small price. Currently, the 3G processor carriers a 412mhz processor, with 128MB ram and 8 gigs storage. Performance wise, this is on par with the computational processors in a top of the line handheld unit like the GeoXH. Even the GPS unit in the $99 3G – which is the worst code-phase receiver since the bad ole days of selective availability – is no real hindrance to turning the iPhone into a killer GIS/GPS platform. You can easily overcome the accuracy issues by “jailbreaking” your iPhone and installing GPSSerial. This allows you to use an external GPS unit in your apps, via NMEA strings. Better still would be roqyGPS and a Bluetooth/DGPS capable receiver, allowing you to stream data into the integrated Bluetooth controller in the iPhone. In other words, wireless 1-10m CEP GPS and a touchscreen handheld, all for a total cost of less than $200! Throw in a service contract with AT&T, and you can even broadcast said data across the internet in real-time, anywhere you receive 3G coverage. With these sorts of modifications, the iPhone could become a real asset for cheap research, especially among graduate students looking to do a pilot study sans grant money.
Unfortunately, a major obstacle to transforming an iPhone into a data gathering monster has been the nature of iPhone development. Developers have been much more interested in writing yet another “Boobs!” app (of which there are hundreds), rather than exploiting the potential of the iPhone hardware.
Until now, that is. Enter Geometry IT, which has developed the iGIS application, available for a mere $20. iGIS is “the first GIS for the iPhone”, and (as a total and complete nerd) I simply had to purchase the app.
After downloading, the first thing I noticed about iGIS is the large and intuitive interface. This is no small feat in the world of GIS, where the GUIs frequently pushes the boundaries of the esoteric.
Undoubtedly, the strongest feature in iGIS is the ability to work directly with the ESRI shapefile format directly within your iPhone. Data format conversion is a major headache for GIS professionals and requires a serious attention to detail if it is to be done properly; improper conversions between formats can seriously degrade the accuracy of your data if not done precisely according to form. Moreover, even said conversion is done properly, the attribute data lurking behind each feature is often lost or attenuated. So shapefile support, on the iPhone no less, is a feat in and of itself.
To begin, I selected six data layers from the FGDL to import into iGIS. These layers ranged in both the type of feature they represented (points, lines, polygons) and the scale at which they covered (county or state). I also paid attention to the number of features within each layer, and selected several layers with a large number of records in an attempt to push iGIS to the breaking point. Below is a summary list of the files that I chose:
- Tallahassee Springs (37 point records, 3 counties)
- County Boundaries (67 polygon records, statewide)
- Springs (589 point records, statewide)
- Public Lands (1860 polygon records, statewide)
- Leon Water Bodies (4457 polygon records, 1 county)
- Leon County Roads (19042 line records, 1 county)
After you select your layers, but prior to uploading your files, you need to associate a projection with each layer. At this point, iGIS revealed an outstanding feature: a comprehensive EPSG projection library. If you’ve never worked with EPSG codes before, let’s just say the EPSG library is gargantuan and attempts to encompass every projection known to man. Apparently, iGIS has some facility to detect the coordinate system used by shapefiles, although I received 5 successive error messages telling me that this automatic detection failed. This was not an issue, in any event – I prefer to set the coordinate system manually to ensure that it is done correctly. More to the point, any user ambitious (and geeky) enough to pay $20 for a GIS app will probably be aware of the issues surrounding coordinate systems, and where to find said information in the metadata.
The import process revealed the first bug in the iGIS software. Despite repeated attempts, the Public Lands layer for the state of Florida failed to transfer successfully. Throughout my exploration of iGIS, I encountered several instances where iGIS failed outright, either crashing or failing to display a layer correctly. Most of these failures seem reflect an inability to deal with small scale shapefiles, i.e. shapefiles which extend over a wide geographic area, rather than layers with a large number of records (more on this in a moment).
Af
ter importation, layers are managed via the project menu. After creating a new project, you select the layers you wish to utilize in your map. There is also a rather nice “zoom scale” feature, where you set the scale at which each layer becomes visible. This is an important consideration, given the limited processing ability of the iPhone, and the ability to determine the scale at which each layer becomes visible is a definite ease on processing time. You can also choose which layer works with the interactive map tool.
Within the project menu, you can also customize the basic symbology of the each layer. Unfortunately, the options for customization are quite limited, allowing you to alter only the size, color, and transparency of each feature. There is no option for using custom symbol sets, so your choices are limited to circles and lines of varying sizes and colors. Also lacking is the ability to assign different symbols based on the data based on the attributes of your data. For example, it would be nice to be able to assign larger symbols for springs with a magnitude of 1, slightly smaller symbols for springs with a magnitude of 2, etc. Similarly, the ability to display roads differently based on their class (divided highway, 2 lane, etc.) is missing as well. Admittedly, you can utilize ArcMAP or another desktop GIS to create a shapefile for each “class” of symbols and import each of these layers into iGIS, but a greater control over the symbology within iGIS would be quite useful, particularly when you have numerous features coded by ID numbers.
After setting up your project, you can proceed with opening the map window. The map window is extremely visually pleasing – the basemap is drawn from Google Earth, with the Google watermark is clearly visible in the lower lefthand corner – and generally consists of 1 meter, cloud free images for densely settle areas. I did notice that sparsely populated areas have the “patchy” look characteristic of lower resolution imagery, but did not investigate the extent of these areas in any detail. Zooming in is handled by the conventional double tap or “reverse pinch”. Oddly enough, however, triple tapping is missing as a shortcut to zoom out; only the “normal pinch” works for this.
iGIS successfully displayed the county layers quickly and accurately, regardless of the number
of features each layer contained. (Layer visibility is easily quickly handled from the map window.) Quite frankly, I thought my iPhone would choke on the 4,000+ polygons in the water layer, not to mention the 19,042 line segments in the roads layer, but in this instance, I was pleasantly surprised – iGIS ran both layers simultaneously with no problems, and required only a few seconds to redraw each time the map was altered. I’ve actually seen much slower performance out of ArcGIS running on an older machine. All features closely matched the basemap imagery, particularly the Tallahassee Springs layer, all of which were on target (I’ve actually visited most of these springs). The roads layer was slightly imprecise, but quite frankly, this was probably the fault of the original shapefile, not iGIS.
iGIS also features a simple to use identify tool. After tapping the identify button, a red circle with a fixed diameter appears on the screen (relative to the size of the screen, not the scale of the map). When you tap the screen again, iGIS brings up a menu listing all of the features within the diameter of the tool, and by clicking on the appropriate feature you can view all of the attribute data of the feature at hand. The only major problem with this tool is swapping the layer which the tool is identifying. In order to change the layer associated with the tool, you have to exit back to the main screen and enter the projects menu. This problem is doubly compounded by the lack of spatial bookmarks in the mapping window, requiring you to repeatedly zoom back into your area of interest. This same problem exists if you want to change the symbology of your layer as well – exit map, enter project menu, exit project menu, enter map, zoom, zoom, zoom…. The end result is tedious, to say the least, and at times turns the inherent pleasure of using a touch screen GIS into a frustrating, repetitive exercise. Better would be a “settings” menu, accessible from map window via one button, where you can change these setting without leaving the map.
Other than the organizational problems with the iGIS menus, it wasn’t until I attempted to display the statewide layers that iGIS began to have serious problems – gagging, 
then choking, and eventually completely asphyxiating my iPhone. You should be aware that iGIS is entirely unable to deal with data that has the spatial extent of, say, a US state. This was first noticeable when I attempted to display the 590 spring locations for all of Florida. Frustratingly enough, the springs are clearly visible in their proper location when viewing the map at a small scale (i.e., zoomed out). One double tap to zoom in later, however, and 90% of the points disappear from the map. Where did they go? Not even the identify tool knows – it acts as if the layer isn’t there at all, despite the layer being marked as present and visible by iGIS.
The statewide county polygons were even worse. Eight consecutive attempts to load this layer resulted in iGIS crashing, sending me back out to the main iPhone menu. The ninth attempt resulted in a total freeze of my iPhone, requiring me to turn the phone off completely and reboot.
The final feature I wish to discuss is the ability to annotate your maps with your own data. Currently, you can add point locations within iGIS, which allows you to specify the name of each data point and any comments associated with it. This layer can then be exported to the shapefile format. The attribute table within this shapefile contains a column for names, a column for your comments, and a column giving the timestamp for each point that you have created.
While this is a nice feature, it leaves quite a lot to be desired. The first problem with this function is that it repeatedly crashed the iGIS app. This needs to be fixed, as the lack of spatial bookmarks requires you to restart the app and repeatedly zoom in to you AOI yet again. More importantly, however, the ability to create attributed shapefiles in situ is a defining task of portable GIS software – other than the accuracy of a carrier-phase receiver, this type of functionality is what you pay out the nose for when you purchase a Trimble handheld. One comment box per point is simply too limited. Many observations require multiple measurements, represented in individual columns within the attribute table. In order to take multiple observations at the same location in iGIS, however, you need to create multiple points at the same measurement, or record multiple measurements within one column of attributes – both of which create major headaches in sorting out your data properly after you export to a shapefile. More importantly, iGIS completely lacks the ability to create lines or polygons – both of which are necessary for certain types of data. If iGIS is serious about being a portable GIS platform, and not just a buggy Google Earth clone, this feature needs to be expanded substantially.
Finally, iGIS lack support for raster data formats. (The basemap is, again, standard Google Earth imagery, which looks very nice and works well.) The lack of support for raster imagery is not unsurprising, as raster data is much more computationally heavy than vector data. Given that processing raster files taxes my quad-core desktop to its limits, this is a feature we shouldn’t expect to see any time soon, and it is in no way detrimental to the iGIS software.
The Quick and Dirty Summation:
iGIS is well worth the $20 price of admission for a single reason – the ability to import and accurately project attributed shapefiles in your iPhone. Without reservation, iGIS is cheap relative to other portable GIS solutions, and the ability to create attributed point data, exportable to directly to the shapefile format, is a feature that (to my knowledge) is only found on professional handheld units. Relative to other commercial GIS software, which ranges from $1,000-10,000, iGIS is a steal at $20. Ultimately, however, you get what you pay for, and iGIS is prone to crashes, unable to handle statewide data sets, lacks in functionality, and has an overly awkward menu system. These problems are all the more frustrating because they are largely overshadowed by the unbridled potential for iGIS to become a comprehensive GIS solution for handhelds, whether for work or for play.
The Good
- Ability to import shapefiles directly into your iPhone
- Ability to create points with attribute data, and export these as shapefiles
- Exhaustive EPSG projection library
- High Resolution (1m) basemap
- Quick rendering Time
- Self-evident interface
- Extremely easy file transfers
The Bad
- Repeated Crashes
- Compete inability to handle data over a wide geographic extent
- Menu system becomes very tedious
- Lack of spatial bookmarks
- No support for line or polygon drawing
- Creation of attribute data is limited to a single column
A Wishlist of Features in the Next Version
- Spatial Bookmarks!
- Spatial Bookmarks!
- Spatial Bookmarks!
- Access to the symbology and identify settings from the map window
- Expanded symbology set, including custom symbols and qualitative/quantitative scaling
- Ability to create lines and polygons
- “Add attribute” button when creating features, allowing you create another attribute field for a single feature; alternately (even better), the ability to define a class of features, which have a user specified number of attributes.
