Monday, January 10, 2011

iPhone Navigation and Map Viewer App Review | Bit Map 3 by Nixanz

Do you want to be able to view your hard copy or digital topo bushwalking maps on a high resolution, user-friendly, portable viewer? Want to know where you are on your map, even when outside your mobile's reception area? Want to carry one less device with you while on your bushwalks?
I always have a second look when I see an iPhone app with a local flavour and Bit Map by Nixanz meets this requirement. The developer, Nik Sands, is also a Mac enthusiast which automatically makes him a friend of mine, keen bushwalker, Bushwalk Australia forum administrator/founder, and has produced some useful applications for the Mac which makes this iPhone app especially worth checking out. His OZF viewer  is a great free application for viewing map files with the OziExplorer (.ozf2) suffix.

Bit Map iPhone App
In the past, I have used software such as MacGPS Pro (see my review of the latest version) to view topographic maps which I have scanned, stitched together and loaded into my mapping software. I have plotted routes and waypoints using MacGPS Pro and then uploaded these to my small GPS (Garmin Geko 201), which has shown the route clearly but lacks the background detail, such as contours and features, shown in a topo map. I have found that being able to zoom a laptop screen image to place a waypoint or find the coordinates is much easier than struggling on the original topo map with a magnifying lens as I once used to do. I have often tracked my route with my GPS and downloaded it on my return to MacGPS Pro to view exactly where I had walked.

Niche Market

The developer Nik Sands designed this iPhone app to meet a need for Australian bushwalkers which was not being met by existing devices and software.

Bit Map fills a niche market for bushwalkers who need to view Australian 1:25K or 50K  topographic maps in colour and wish to have the benefits of a user friendly, portable map viewer which can view the maps offline, without the need for mobile reception or a wifi connection. The iPhone with its large, high resolution colour screen (version 4's retina display shows 4 times as much map without loss of image quality as the iPhone 3), large storage capacity for maps and user-friendly touch screen, makes all this possible. This app's primary task is to convert your iPhone into a high resolution map viewer and is not designed to replace your dedicated GPS, although for many people it will be more than adequate. It has many of the basic  GPS's features you would expect such as giving the grid references of your location, speed and allowing you to enter waypoints and upload routes.

Bit Map Screenshot
Unlike expensive proprietary maps which need to be purchased, such as the vector maps of Garmin, and then uploaded into a matching GPS, Bit Map works with bitmapped or raster images which can be user-supplied and produced in a variety of traditional graphic formats such as JPEG, PNG, TIFF, GIFF and even PDF.  In addition, Bit Map  can import OziExplorer maps (OZF2) which are pre-optimised,and are highly regarded in Australia. Maps need to be supplied by the user as there are none built-in, except for a bundled map of the world.


Once converted into a supported digital format, maps need to be optimised for use in the iPhone and this can be done within the iPhone or on a desktop computer using third party software, which is the preferred option, and Nik has supplied some software for this purpose. Pre-optimisation saves lengthy load times as the iPhone doesn't need to do as much processing.
"When you first download a map to your iPhone, Bit Map will automatically split it into small chunks that are easier for the iPhone to handle and will compress each chunk to reduce the amount of storage space used. While viewing the map, each chunk will be seamlessly loaded when it comes into view on screen." (From developers website)
Optimisation stores the maps as JPEGs at 50% quality to save storage space, which will of course result in a small loss of quality.

Maps can be downloaded directly using the built-in web browser if you have wifi access or a large data plan.

In Map View, the UTM zone and grid reference of the current location overlay the map along with the latitude and longitude for the WGS84 datum, and the estimated recent and average speeds.  The grid reference defaults to the WGS84 datum if there is no current map datum available.

"There are two methods of calibrating map files:

The fully manual preparation method requires you to determine and define the region of the Earth covered by each map yourself, and to rename each image file using a strict format to define each map's area.

The .map method uses OziExplorer-compatible ".map" files to automatically determine the area covered by each map, but is only available to OziExplorer users, or people who've obtained maps with associated ".map" files in OziExplorer format.If the image is not pre-calibrated (eg ECW, GeoTIFF) then it will need to be done manually by clicking a few known points and adding their coordinates." (From developers website)
Installation of Map Files and KML, KMZ files
"Maps (converted and calibrated as detailed above) and KML files can both be loaded into Bit Map on an iOS device (iPhone or iPad) using much the same process.  There are three different ways for Bit Map to load maps and KML files.  Choose whichever of these methods suits your circumstances the best:

   1. Using iTunes' file sharing over USB.  This is by far the fastest (by several orders of magnitude) and easiest method if you are able to physically connect the device to a computer running iTunes which also has your map or KML/KMZ files on it.
   2. Uploading files via WiFi from your desktop/laptop to Bit Map, directing the web browser on your Desktop/Laptop to the URL that Bit Map displays in its acquisition view.  While in the acquisition view, Bit Map will run its own built-in web server ready to receive files from web browsers on the local network (NB:  The desktop/laptop uploading the files must be on the same local network as the iPhone running Bit Map, and Bit Map must be displaying it's acquisition view for this to work).
   3. Downloading files from a web server somewhere on the internet (or on your local network) using URLs that you enter into Bit Map itself. This means that you first need to upload your prepared map image files to a web server. Any computer can act as a web server, so long as it is configured correctly. If you don't already have upload access to a web server, you may be able to set up your desktop/laptop as a temporary web server."(From developers website)
GPS Functions
Bit Map screen shot
"Bit Map can record and store several routes (series of waypoints).  Waypoints can be named, and several routes can be displayed on the map simultaneously.  Routes can also be sent to or received from your desktop computer as KML files which can be read by a variety of other applications, including Google Earth." (From developers website)
Unlike MacGPS Pro it can't show profiles, nor load some of the more unusual formats available. It overcomes some of these limitations by allowing the import of .kml and .kmz data already prepared on a desktop computer using software such as MacGPS Pro and the export of any such files generated by email.

Bit Map uses the iPhone's built-in GPS to show your current location on your map and also has the ability to "follow" your location if you are mobile, by centralising the map on the screen as you move, loading new maps as required.
"While in 'Follow' mode, sleep is disabled (only while connected to a power source) and the map is continually scrolled to centre on your current location". (From developers website)
As with many iPhone apps that use the GPS, there is a potential for your battery to drain quickly. (See my recent post "How to Keep your iPhone Charged in the Outdoors")

Browse the developers website for more Bit Map information.
Bit Map Settings Screenshot

The iphone with Bit Map installed will never match my 17" MacBook Pro with MacGPS Pro installed for ease of viewing, profiling and entry of waypoints and routes, nor will it match a dedicated GPS for battery life or robustness, although there are solutions to both these problems. Hopefully you will not need to use your iPhone in heavy rain or when wearing gloves.

It does however provide a compact and mobile map viewer with a limited set of GPS features which will suit many people who don't need the full range of GPS features and in the past have relied upon large laminated paper maps. For some it will mean their GPS will no longer need to be carried on a bushwalk as their phone will do both tasks.

Congratulations Nik on a job well done!

Creative Commons License
This article by Bush Walker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.


  1. how about Galileo offline maps? both offline atlases and KML files could be imported into the app for offline use. extra useful map app for navigation.

    p.s. And maps can be calibrated with mapc2mapc ( in galileo format too.

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