ITB Tutorial Report

OPEN STREET MAP

VINOD GUPTA SCHOOL OF MANAGEMENT, IIT KHARAGPUR

In partial fulfillmentOf the requirements for the degree of

MASTER OF BUSINESS ADMINISTRATION

SUBMITTED BY: Team_Prat Prabhat Agarwal 10BM60059 Prashant Menon 10BM60061 VGSOM, IIT KHARAGPUR

OPEN STREET MAP

1 INTRODUCTION

OpenStreetMap (OSM) is a collaborative project to create a free editable map of the world. The maps are

created using data from portable GPS devices, aerial photography, other free sources or simply from local

knowledge. The various features such as roads and buildings are contributed by users worldwide. The

OpenStreetMap approach to mapping was inspired by sites such as Wikipedia and Google Maps. The map

features a prominent 'Edit' tab and a full revision history is maintained. Registered users can upload GPS track

logs and edit the vector data using free Geographic Information System editing tools.

OpenStreetMap (OSM) was founded in July 2004 by Steve Coast. In April 2006, the OpenStreetMap

Foundation (OSMF) was established to encourage the growth, development and distribution of

free geospatial data and provide geospatial data for anybody to use and share. In December

2006, Yahoo confirmed that OpenStreetMap could use its aerial photography as data for map production.  In

Nov 2011, OpenStreetMap is having 500,000 registered users.

1.1.A Prerequisities for using Open Street Map:

We need internet connection and a computer. If we want to collect data then we also need a GPS tracking

device. The data are also available on net which we can use. Before we are able to contribute to

OpenStreetMap we will need to sign up and agree to the conditions under the license that OpenStreetMap uses.

This is an important stage and allows every contributor to the project to see who has added data to the project

and possibly send them a message. The terms and conditions ensure that anyone can use the work in future

without needing to ask for permission each time.

We do not need to use our real name as user-name, many people use other names to create user ID. We will be

required to provide an email address to authenticate our account, but this will not be made public. We will

receive emails when other members of the community sends a message, but not otherwise.

The guide is organised into five stages as follows:

1. To collect data using a GPS unit or by other methods.

2. To upload GPS data (skip this section if you are not using GPS).

3. To edit maps to make changes to OpenStreetMap.

4. To edit data, add tags and upload changes.

5. To render maps.

2 STAGE 1: DATA COLLECTION

2.A There is variety of ways to gather data for OSM:

GPS – It is the most common way of gathering data for OSM and often preferred for collecting the

initial geometry of roads, paths and other ways.

Local knowledge –One of the best source of data, as one knows the area very well, like the names of

the roads, shops or buildings, the local traffic rules and restrictions, or one might want to add to

OpenStreetMap. If the basic road layout is already present we can directly use it.

Aerial imagery - are available to OSM for tracing data from. The mapping an area properly requires

someone on the ground to verify and to add information that cannot be gathered from these sources.

We will find it much easier to trace something from aerial imagery if you know the area and already

have a mental picture.

Data may already be collected that requires people to convert it into a map.

Seeing mistakes in a map and fixing them

2.B What data to add:

There are lot of data that can be put into OSM: from common things such as 'street names' to fine details

like parks, postboxes, shopping malls, etc. Commonly people using it increase the detail as they go on,

but start with the basics. So the main road network tends to be a good starting point, and lesser things

such as foot path, or postboxes are among the final bits to be added. The list of some of the things which

can be added are :-

Parks and playgrounds

Shopping malls and supermarket

Accomodation

Transport areas

Water-bodies, Lakes and drains

Power Supply

Barriers

Man-made structures.

3 STAGE 2: UPLOADING GPS DATA

3.A The following steps need to be taken to upload GPS traces to OSM, and download it

into JOSM for editing.

1. Save Your Files to GPX - If the data have been collected with a GPS receiver we need to save the

file in GPX format. If GPX is available, save it as GPX file. If GPX is unavailable, save the track in

another format and use a converter program to change it to GPX format.

To convert tracks to GPS using GPSBabel

First we need to download GPSBabel.

Unzip it into a directory.

Open the GPSBabelgui.exe file.

In Input select saved track type and browse through track file.

In Output select GPX XML and a destination file.

Press "let's go".

2. Upload To OSM – Once we have a GPX file containing a GPS trace, we should upload it to the site.

It is desirable that all GPS traces used to create OSM data to be uploaded to the site, so that all OSM

data has a source and so that others can reuse the data in the future.

How to upload data

Go to the main OSM page and Login.

Click “GPS traces” along the top and Click on "See just your traces, or upload a trace".

Find and select the file we wish to upload.

Name the file.

Add helpful tags that can be used to find it.

If we would like our data to be available to others tick the "Public?" box.

Click "Upload".

The data will now take a short while to be included into OSM. However, as soon as data is

uploaded it, we can immediately use it.

Once done you can download the data from the editor JOSM, along with all other data in that

area.

3. Download the Data into JOSM - JOSM is a java-based map editor. 

To edit by JOSM, we need to download OSM data and GPS traces from OSM database into the

application:

Click File -> Download from OSM menu

Navigate to the area we wish to edit, by using: Mouse wheel: zoom in/out

Right click and drag: move the map

Left click and drag: mark the area to download

At the top of the download window choose what to download:

1. OpenStreetMap Data: OSM map data, we will edit this, so we will certainly need this.

2. Raw GPS Data: Data gathered from GPSs by OSM users. It's recommended to download

all GPS tracks for more accurate drawing.

Click Download.

4 STAGE 3: EDIT MAPS

We have a choice of two main editors:

1. Potlatch - is the easiest editor to get started with and is available directly from the 'edit' tab.

2. JOSM - It is preferred by many experienced contributors but needs to be downloaded separately

and takes a bit more effort to get started with.

4.A Potlatch – Online Editing

Potlatch is an editor for OSM data. To use it, we first must sign in or register (see the top right of the

Potlatch screen for the "log in" and "sign up" links). Then, to start, navigate to a map location on

www.openstreetmap.org and click on the 'Edit' tab along the top of the screen.

The following commands are useful for editing with Potlatch

To add a point to an existing way, select the way and shift+click at the desired location.

To delete a point, select the way and click the Delete Item button in the bottom right corner or

press Delete (or Backspace) on the keyboard.

To delete a way, select the way and click the Delete Item button in the bottom right corner or

press shift+Delete (or shift+Backspace) on the keyboard.

To move a point, click and drag the point.

To move a way, click and drag the entire feature (hint: grab a segment where we won't

accidentally move a node).

To extend a way, click on one of the end points of the way. Then continue drawing as usual.

To add a new way extending from an existing way, shift+click on one of the end points of the

way. Then continue drawing as usual.

To split a way, select the point at which we want to cut, and click the Scissor tool or press X on

the keyboard. (Hint: Add a node first in order to cut between nodes.)

To make a junction between two ways, draw as usual until we need to make a junction. Then as

we move our mouse over another way, the points will light up blue. Click on one of the blue

points or any other desired location on the way to make a junction.

To disconnect a junction, select the point on the way we wish to alter. Then press (-) on the

keyboard to remove the point.

To reverse the direction of a way, click the Reverse Direction button in the bottom right corner.

The direction of a way is only a concern for those features with a "oneway" tag - oneway streets,

coastlines, islands, and so on.

To create a way running parallel, select the way and click the Create Parallel Way button in the

bottom right corner or press P on the keyboard.

To create a way that shares nodes with an existing way, start drawing, click the first two shared

nodes, then press F to automatically follow the existing way.

4.B Using JOSM – Java based map editor

1. Install JOSM - First we need to go to the JOSM download site (http://josm.openstreetmap.de/)

and get the latest version. At the bottom of the page we'll find the 'download' link. Save the 'josm-

latest.jar' file on our desktop.

If everything is okay, one should have the JOSM editor application now running and the page

looks like:

2. Download a MAP - To do this go to the OpenStreetMap website

(http://www.openstreetmap.org/). Search for the map of the city to be updated. e.g. 'Kolkata'.

Click first on a search result and then on the 'view' tab on the top of the webpage to see the URL

of the page or HTTP address in our browser location bar.

Now, copy this URL with ctrl-c and go to our JOSM application.

Open 'File -> Download from OSM -> Paste the above selected URL and press ‘Enter’.

4.C OSM's data is made up from the following elements:

Nodes: The dots that are used to mark specific locations (such as a post box) or for drawing

segments between.

Ways: An ordered list of nodes, displayed as connected by line segments. They are used to

describe roads, paths etc.

Closed Ways: Closed ways are ways which go in a complete loop. They are used to describe

areas like parks, lakes, islands or buildings.

Relations: When different ways are linked to each other, but do not represent the same physical

thing, a relation is used to describe the role of each way. They are used to describe things like

cycling routes, turn restrictions and areas with holes.

The end result of should be a window containing a vector view of our map:

5 STAGE 4: EDIT DATA

Once we have completed map editing, we need to add tags in order to see them rendered on the map.

Tags are key-value pairs describing properties of a way or node, such as its name or its type. The data

needs to be interpreted by applications to be useful (e.g. to render a map) and so it is best to try and use

one of the well established tagging practices.

5.A Tagging :-

There are 3 data types that may be tagged:

Node: Just a node/point used to mark a particular point on the map.

For example: A town or a theatre may be marked using a node 

Linear: A way used to mark a particular linear item on the map.

For example: A motorway or a river may be marked using a way 

Area: A closed way to mark a particular area on the map.

For example: A lake or a town may be marked using an area 

5.B Upload the data:

The Potlatch editor will upload changes to the server when we save. It will also automatically update the

view (in case someone else is simultaneously editing in the same area).

If we are using an offline editor, such as JOSM, we need to sync our changes with the server before they

take effect:

Re-download the area we have edited. This checks that the area we have been working on has not

been altered by somebody else in the time we have been editing.

If there are conflicts, compare them and pick which one we think is correct. Conflicts can be

viewed in the side bar section, opened with alt-c. We should be informed when conflicts occur.

Upload the changes.

6 STAGE 5: RENDER THE MAP

To transform the vectorial view of the map into something more artistic is called rendering. We need to

process the sample.osm file with some tools (eg: osmarender) and calculate all colors, images, streets,

waterways, etc that we need to put on the map. We need to download two files and save them into the

'openstreetmap' directory:

osm-map-features-z17.xml

osmarender.xsl

The first file is a features file which tells the osmarender what we want to put on the map. The second file

is a stylesheet that directs the actual rendering work.

Osmarender: A renderer based on Extensible Stylesheet Transformation (XSLT) that is able to create

Scalable Vector Graphics (SVG), which can directly be viewed with some web browsers or converted to

bitmaps.

7 EXPORTING THE MAP

By the export tab, we can also select a piece of the map and download the data in several formats,

including OSM XML. This works only at small zoom levels. The region is specified by a bounding box,

which consists of a minimum and maximum latitude and longitude. We choose as small a region as will

be useful. This sidebar display includes the four values we need for a bounding box matching the extents

of the viewport. By clicking 'Manually select a different area' and then we can drag a box to select exactly

the region we want.

8. ADVANTAGES:

OpenStreetMap can use available satellite imagery to map the roads, buildings and refugee camps

during crisis conditions like earthquake, floods or other natural disasters.

The resulting data and maps can be used by several organizations providing relief aid, such as Red

Cross, etc

It is compatible with Ushahidi mobile platform (a non-profit tech company that develops free and

open source software for information collection, visualization and interactive mapping).

9. BUSINESS VALUE:

We can form association with different mobile service provider which will use this data to display

maps on mobile phones and other GPS supporting devices.

The data will also be of use to different Driving Teaching agencies which uses street information to

teach driving.

The data of the street maps can be sold to different game developing vendors which use street

information in their high end games.

We can also use the data to make segmentation for doing market survey of some particular products.

The data can also be used by financial intermediaries like bank etc to prepare a loan portfolio of a

particular region or to prepare credit default rating of a region.