First a brief note about OpenStreetMap. OpenStreetMap is an open source community driven mapping project that comprises data, tools to edit the data, and tiling services and other services to view
and reuse the data. It is built on PostgreSQL, our favorite relational database. Unlike other tile services such as Google Maps and Microsoft Bing, the tools and various backup mirrors available allow you to download all the data for your
region and setup your own customized tiling service in house. This is actually the main reason we are interested in using it.
Many of our clients have networks where because of firewalls, portability, general security concerns, need for further zoom in options for their area of interest, or just need to hide/add more layers to the tiles
than what OpenStreetMap or other tile services provide out of the box, they need to be in control of the whole process.
So in short, what does OpenStreetMap provide that the other tiling services don't:
- More generous licensing terms: For more details about the licensing check out OpenStreetMap License. Though it is more generous
it is not without its restrictions.
- You can download the data and load it up into your PostgreSQL / PostGIS database and query it. It has a ton of useful information like locations of various places of interest - restaurants,
museums, hospitals, etc.
- Several Tiling service themes to choose from - Osmarender, CycleMap, MapNik and so forth, which you can access from various free mirrored tile servers. In general with Google Maps and Bing, you just get one road network
- If you are not satisfied with the tiles or the depth of zoom levels offered, you can build your own tiles and also style them as needed, removing features you don't care for and adding others.
For example for Boston, I need more zoom levels than what is offered by the OSM services and I really don't care to allow people to see the rest of the world.
On the downside, there is not yet an Aerial offering to compete with those of Google or Bing.
Now getting back to the book.
How long is it?
As books go, it is a fairly short book at 252 pgs, but covers a fair amount of ground in those pages.
Who is the book targeted at?
The book is a fairly light-read and targeted at those individuals with little to no knowledge about mapping, GIS, or data collecting, but who want to contribute to making
a freely available map of the world. It is also targeted at hobbyist surveyors or wannabee hobbyist and community surveyors. Finally it's also targeted at programmers who want to customize
OpenStreetMap for their use-cases.
How is the book Organized?
Chapter 1 and Chapter 2: Are intros to OpenStreetMap, what is it, how to register to start editing. Places where the community hangs out e.g. Chatting on IRC, Mailing Lists, Forums. Where to find
planet osm bulk files (which are huge),
If you are familiar with OpenStreetMap, you can get away with just skimming these chapters, but there are tidbits here and there that I was unaware of.
Chapter 3 - Chapter 7 Are chapters meant for people who want to contribute data via thier own GPS journeys or who want to edit / QA features on the map.
- Chapter 3 - Gathering data using GPS introduces you to what GPS is, NAVSTAR, and Global Navigation Satellite System (GNSS), GPS traces. Equipment you need to get started doing GPS traces. It doesn't make any specific suggestions about brands
of GPS to use, but does cover classes found such as smart phone built-in, car mounted, USB, etc. and configuring them so they can be easily imported into OpenStreetMap. It also covers Photo Mapping
and Audio mapping.
- Chapter 4: How OpenSteetMap Records Geographical Features - This one while geared towards map editors, is a good one to read if you want to load the data into your own database and query it.
It covers the various OSM primitives such as Nodes, Ways, Relations, Changesets, and tags and how they work together. It covers dos and don't about data tagging.
- Chapter 5: OpenStreetMap's Editing Aplications - There are several tools available for editing OSM data. This chapter covers the most supported ones and a brief summary of the pros/cons of each.
- Chapter 6: Mapping and Editing Techniques - This covers how to use the editing tools to draw nodes, lines, add tags and so forth. The techniques covered are applicable to all the various editing tools.
- Chapter 7: Checking OpenStreetMap Data for Problems - covers how to use the various OpenStreetMap QA tools and how to find unsurveyed areas
Chapter 8-10 Are chapters geared for the programmer looking to customize OpenStreetMap look/feel and offerings for their own needs. This is the part I was most interested in
and am still going thru. It's the most advanced of the book and to take real advantage of it, it helps to follow the instructions step by step rather than just reading it.
- Chapter 8: Producing Customized Maps Covers simple exports using the API, Kosmos, and Osmarender tools.
How to create your own customized tiles with Kosmos (which is sadly no longer being developed according to the book), SVG Maps with Osmarender. One thing I found sorely missing in this chapter was at least
some coverage of using Mapnik to generate tiles or Osmarender/Tiles@Home to render tiles which are described in Creating your own tiles.
- Chapter 9: Getting Raw OpenStreetMap data This was my favorite chapter, probably because I love raw data. It's like getting raw marble and being able to carve it to your own liking.
This chapter covered the various ways you can get raw OpenStreetMap data -- Planet files, the main OpenStreetMap API, and Extended API. It also talk about cloudmades downloadable
extracts available in various formats including the very popular ESRI Shapefile format and also partitioned into various geographic sets for easier download.
- Chapter 10: Manipulating OpenStreetMap data using Osmosis covers how to use the commandline osmosis tool for cutting regiions and features of interest out of a planet osm file and also using its splitting and merging features.
Chapter 11: OpenStreetMap's Future Briefly covers what is coming in OpenStreetMap such as the new data license, and MapCSS initiatives.
Overall I thought this was a good intro book to OpenStreetMap that gave you a good ground to build on. It gave you enough informaton about terminology used, basic workflow and
links to get more advanced information about the tools commonly used and how to use them.