GIS Tips – Repair broken links using python

I’m not going to lie, I don’t like python, probably because I’m turning into my dad and slowly find myself finding things a little harder to learn….I think being able to cope with C++, C#, VBA, HTML, CSS, Ferranti Fbasica, Cobal & (My favourite) Sinclair Basic, should be enough for anyone, python just tips me over the edge.

What grinds me even more though, is the ArcGIS broken links…even when you have the relative paths set, it still throws a fit every now and again and you lose all the links.

Of course, it should be easy, we all know about the trick of clicking on the red exclamation mark so that we can relink all the data again, don’t we? Here is a quick refresher fromt the ArcGIS help page:

From ArcGIS 10.0 help page 30th November 2013

When you open a map, ArcMap looks for the data referenced by each of the layers in the map. If ArcMap can’t find the data source for a particular layer, that layer won’t be drawn. You can immediately tell whether a layer on your map has a broken data link because it will have a red exclamation point next to its name in the table of contents, and the check box next to the layer will be unavailable.

Broken data link in the table of contents

A layer needs repairing if the data source it references has been moved, renamed, or deleted or is inaccessible for some other reason.

There are a number of ways to repair broken data links, which are described in the following sections:

Repairing a broken link for one layer

If you only want to repair a broken link for a specific layer, click the Set Data Source button on the Source tab of the Layer Properties dialog box.

Click the Set Data Source button to enter the correct dataset location.

This lets you specify the layer’s data source by browsing to it. Select the desired data source on the Data Source dialog box and click Add to repair the layer.

Repairing broken links for multiple layers

You may find that several layers in your map need repairing. For example, if a geodatabase containing data sources that are used for multiple layers in your map has been moved or renamed, all these layers will need to be repaired. If you want to repair several layers at once, right-click the layer with the broken link and click Data > Repair Data Source. You can also click the red exclamation mark to open the Set Data Source dialog box as shown here.

Repairing multiple data links

When the repair to the data link is made from the table of contents, ArcMap repairs the selected layer using the data source you browse to and automatically repairs other broken layers if it can find their data sources in the same location of the data source you specified.

Repairing broken links using python

Now, even with my limited python ability got the following to work. In this scenario, the data was located directly under the C:\Project\Data folder but was moved into a subfolder called Data2. This script updates a single map

document.import arcpy mxd = arcpy.mapping.MapDocument(r"C:\Project\Project.mxd") 
mxd.findAndReplaceWorkspacePaths(r"C:\Project\Data", r"C:\Project\Data2") 
mxd.saveACopy(r"C:\Project\Project2.mxd") del mxd

Easy peasy, but to be honest this may just be as easy as clicking on the red exclamation mark in most scenarios. But what if you tranformed all the data from shapefiles into your geodatabase?…This is where the python excels (using the exclamation mark method won’t work for this)

Re-linking data that has changed formats

This scenario involves updating two different workspaces in a map document. First, shapefiles are redirected to a file geodatabase called Parcels.gdb. Second, layers from a personal geodatabase are redirected to another file geodatabase called Transportation.gdb.

import arcpy mxd = arcpy.mapping.MapDocument(r"C:\Project\Project.mxd")
mxd.replaceWorkspaces(r"C:\Project\Data", "SHAPEFILE_WORKSPACE", r"C:\Project\Data\Parcels.gdb", "FILEGDB_WORKSPACE") 
mxd.replaceWorkspaces(r"C:\Project\Data\Transportation.mdb", "ACCESS_WORKSPACE", r"C:\Project\Data\Transportation.gdb", "FILEGDB_WORKSPACE") 
mxd.saveACopy(r"C:\Project\Project2.mxd") del mxd

That wasn’t so painful was it? Before I sign off, I have to credit for the inspiration for this post, as the first python script I reference is based on one which they posted way back in 2011 for ArcGIS 10.0Nick D

ArcGIS Professional – Lots of rumours….but what is it?

There is a buzz in the ESRI camp, its shrouded in mystery and plenty of talk about a new application which ISN’T ArcMap, ISN’T CityEngine or Enterprise…..ESRI have gone to town with the ninja marketing, even though this new application isn’t due out until Q1 (or 2) next year there is a new Twitter account (@ArcGISPro) and also some brief talks on the ESRI site.

But WHAT IS IT? As a GIS Consultant, I already have people asking me questions as to whether it will be suitable for them….

Well….back in July,  Jim McKinney gave a talk on the future of GIS, in this he discussed a new product;

“The most important goal, build what you’ve been asking for, be it on ideas that or enhancement requests or speaking face-to-face at events and conferences…we want to make sure that this is really valuable for you in your critical workflows.

Another one is build a 64-bit application, finally, with super-fast display and integrated 2D and 3D views…a new contextual user experience only showing tools when you need them, powerful spatial analysis and editing capabilities, tight integration with Esri solutions. ArcGIS Online, and Portal for ArcGIS; and simplify the interface and the application wherever we can.”

  • During the talk, Jim demonstrates being able to take in CityEngine data as well as ArcGlobe data and data from an MXD….Finally a full integration of the many ESRI products?
  • Jim shows the interface and it is very “Microsoft” in nature, more akin to ArcGIS Explorer, with a “home” button and tabs – ArcGIS Explorer on steroids? or a more efficient way to manage all those tools?
  • My favourite part of the demonstration by far is when he brings up 2 linked views on the screen….one in 2D and the other in 3D… really demonstrates how flexible the sotware is..

One of the key points which I pick up from this is “This is the new generation of ArcGIS”….so is this finally the ArcGIS 11 which we were all waited with bated breath for? 64bit, fully integrated ArcScene, ArcGlobe, ArcMap and with 2D & 3D output? IT SEEMS SO!…..

It’s early days and rumour is that it is currently in beta at the ESRI camp….for the latest news and images, go over to Twitter and look up @ArcGISPro

Nick D 



Ten of the Greatest Maps that Changed the World

I’ve had this bookmark on my computer for the last 2yrs and I find that every now and again I visit the page and have a little look…the inner cartophile inspired and humbled by the beautiful work presented here. My personal favourite is the “London Poverty Map”, not just because of the lovely hand draw detail, but also the amazing story behind it, how one man disagreed with what he was told and created a map that changed the way that the councils worked.

The article is from the UK Daily Mail, though it has been written by Pete Barber, Head of Map Collections at the British Library

Ten of the greatest: Maps that changed the world


From the USSR’s Be On Guard! map in 1921 to Google Earth, a new exhibition at the British Library charts the extraordinary documents that transformed the way we view the globe forever

By PETER BARBER, Head of Map Collections at the British Library

UPDATED: 22:00, 8 May 2010

1. BE ON GUARD! 1921

The infant USSR was threatened with invasion, famine and social unrest. To counter this, brilliant designers such as Dimitri Moor were employed to create pro-Bolshevik propaganda.

Using a map of European Russia and its neighbours, Moor’s image of a heroic Bolshevik guard defeating the invading ‘Whites’ helped define the Soviet Union in the Russian popular imagination.

Be on Guard!


It’s said that Columbus used this map or one like it to persuade Ferdinand of Aragon and Isabella of Castile to support him in the early 1490s.

The map was made by a German cartographer living in Florence and reflects the latest theories about the form of the world and the most accurate ways of portraying it on a flat surface.

It seemed to prove that, as Columbus argued, there wasn’t a great distance between Europe and China by sea.

The map is also the first to record the rounding of the Cape of Good Hope in South Africa by the Portuguese in 1488.

This proved that there wasn’t a land link to Asia in the south – and that Europeans could reach the riches of the East Indies by sea without having to go through Muslim-held lands.

Henricus Martellus World Map

The Henricus Martellus World Map was the first to record the rounding of the Cape of Good Hope in South Africa by the Portuguese in 1488


Made for the Chinese Emperor, this is the earliest known Chinese terrestrial globe, and a fusion of East and Western cultures.

Its creators are thought to be the Jesuit missionaries Manuel Dias (1574-1659), who introduced the telescope to China, and Nicolo Longobardi (1565-1655), superior general of the China mission.

Both were respected scholars, and the globe’s depiction of the coasts of Africa and Europe would have contrasted with traditional Chinese maps.

These exaggerated the size of China and placed it in the middle of a world that otherwise consisted mainly of small offshore islands.

In its treatment of eclipses and meridians and its information about magnetic inclination, however, the globe draws on ideas that were developed in China far earlier than in the West.

Chinese Globe

The Chinese Globe which was made for the Chinese Emperor in 1623


‘America’ is named and envisaged as a separate continent for the first time on this map, put together by a think tank in Saint-Dié in the Duchy of Lorraine.

The map itself was created by a skilled cartographer, Martin Waldseemüller, and was accompanied by an explanatory booklet by one Matthias Ringmann. Impressed by the writings of Florentine navigator Amerigo Vespucci, Ringmann suggested that the Americas weren’t part of Asia, as Columbus thought, but a continent in their own right.

So they should, like the other continents, have a female name – hence America, after Vespucci’s first name. Perhaps to emphasise the independent existence of the Americas, the map shows what we now know is the Pacific lapping the western coast of South America, though its existence was only confirmed years later.

Waldseemuller world map

The Waldseemuller world map named and envisaged America as a separate continent for the first time

5. GOOGLE EARTH, c2005

Google Earth presents a world in which the area of most concern to you (in this instance, Avebury in Wiltshire) can be at the centre, and which – with mapped content overlaid – can contain whatever you think is important.

Almost for the first time, the ability to create an accurate map has been placed in the hands of everyone, and it has transformed the way we view the world. But it comes at a price.

There are few, if any, agreed standards about what should be included, and the less populated and ‘less important’ regions get ignored.

Google Earth

The ability to create an accurate map has been placed in the hands of everyone with Google Earth


Businessman Charles Booth was sceptical about a claim in 1885 that a quarter of Londoners lived in extreme poverty, so he employed people to investigate.

They found the true figure was 30 per cent. The findings were entered onto a ‘Master Map’ using seven colour categories, from black for ‘Lowest class, semi-criminal’ to gold for wealthy.

The authorities were terrified into action, and the first council houses were built soon afterwards.

Map of London poverty

This map of London showed that 30 per cent of people lived in extreme poverty


This map was used by British diplomats negotiating an end to the American War of Independence in Paris. Richard Oswald, secretary to the delegation, annotated it with coloured lines to show where it was thought past treaties established the U.S./Canada border.

In the event, when drawing the northern border the Americans asked for less than expected, and in the century afterwards they tried to renegotiate.

To prevent them from seeing this embarrassing map, it was removed from the British Museum, where it had been since the 1820s, and placed in the Foreign Office.

'Red Line' map of North America

The ‘Red Line’ map of North America was used by British diplomats negotiating an end to the American War of Independence in Paris


Dismissed as too ‘revolutionary’ when it was first submitted in 1931, Harry Beck’s Underground map solved the problem of how to represent clearly and elegantly a dense, complex interweaving of train lines.

Placing the stations at similar intervals regardless of their true locations amplifies the area of central London, increasing its clarity, while the straight lines and interchange symbols confer a simplicity and order on the network. A cartographic icon.

London Tube Map

Harry Beck’s Underground map solved the problem of how to represent clearly and elegantly a dense, complex interweaving of train lines


It’s impossible to portray the reality of the spherical world on a flat map. The familiar ‘Mercator’ projection gives the right shapes of land masses (up to a point), but at the cost of distorting their sizes in favour of the wealthy lands to the north.

The German Arno Peters sought to correct this. His projection gets the proportions (roughly) right, and has the effect of emphasising the Third World. That said, it’s no more ‘true’ than the ‘colonialist’ projection it seeks to replace.

Peters Projection World Map

The Peters projection world map got the proportions (roughly) right in 1974


Created for the prior of Evesham Abbey, this map marks the birth of modern English patriotism.

The top is a world map in the traditional medieval sense, with the Garden of Eden, the Tower of Babel below and a large multi-towered Jerusalem.

But at the bottom an enormous England stretches from Scandinavia to the Mediterranean. The very large tower above the French coast is Calais, captured in 1347.

We are in the age of Henry V and Agincourt.

Evesham World Map

The Evesham World Map marks the birth of modern English patriotism

Ordnance Survey back the need for cartogtraphic design

What is a map? Is it the data or the way it is representated so that it can be understood?….Pretty much the eternal “chicken and egg” scenario.

It is refreshing to see that today (15th October 2013), Ordnance Survey, the award winning cartographers and UK survey specialists, have released a plethora of guides on cartographic design.

Information like this is normally confined to expensive books and seminars, this is available free to anyone, GIS specialist or Minecraft wannabe. What makes this such necessary reading is that Ordnace Survey have always been at the leading edge of cartographic design, so for them to share even a fraction of their knowledge back to the industry is fantastic.

Okay, so it’s not going to turn us all into world leading cartographers overnight (well, I say “us” loosely), but it WILL give us the edge in a very competitive environment.

Go and have a look, it’s a fantastic resource: Ordnance Survey Cartographic Design

GIS Tips – GIS and the Law

I love my job, whether creating works of art or building a new tool for automating some mundane task, it keeps me busy and stops me from causing trouble. One thing I don’t enjoy though, is the legal side of GIS.

Every data has a source, which someone, somewhere has created and owns rights to that data. A typical map or cartographic representation may contain 10 to 20 of these layered data sources….so where on the limited space do you put all those sources, furthermore, who are they? They were probably supplied by your line manager who got them from a sub-contractor who got them from a surveyor who nobody got the name of……

There are a wealth of books on this subject, I know, I have all 4 of them and was looking to write one myself, probably entitled something like “Before you publish your map, caveat EVERYTHING”, until I came across the Maine University website for the “First Readings of GIS Law“.

There are some great resources here and references to books which I have only heard of. Please have a read of some of the page below.

Written by Professor Harlan J. Onsrud of University of Maine.


First Readings in GIS Law

Note: The readings referenced in the following paragraphs are recommended for obtaining an initial overview of the legal issues surrounding the use and development of geographic information technologies and databases. HJO

The use of geographic information technologies is pervasive throughout business, government, industry and the scientific community in the United States. Conflicts are arising on a daily basis for those using geographic information systems and their affiliated databases, for those implementing such systems, and for those designing the next generations of spatial information technologies. Balancing among competing interests and resolving conflicts involved in the use of these technologies are growing problems for numerous parties within society. Among the problem domains of greatest concern in use of these technologies are those involving personal information privacy, intellectual property rights in geographic information, liability in the use of geographic data sets, public access to government geographic data sets, public goods aspects of geographic information in libraries, and sales of geographic information by government agencies.

Conflicts in regard to personal information privacy have become much more pervasive throughout the geographic information community within the past few years. Clarke (1999), Marx (1998), Hernon (1997), Curry (1997), Ontario (1997) and Onsrud et. al. (1994) provide more extensive discussions of the range of privacy conflicts in the use of geographic information. There also is a burgeoning literature on information privacy issues generally. A search of “information privacy” on Uncover reveals over 400 professional journal articles published in just the past two years alone. Also witnessing unprecedented growth in addressing information privacy issues are books, government reports, conferences and web sites (respective examples include book: Agre and Rotenburg (1998), reports: U.S. Dept of Commerce (1997), U.S. Senate Judiciary Committee (2000) conference: Cyberspace or Privacy: A New Legal Paradigm?, and web site:

For a discussion of conflicts and societal harms related to competing claims over intellectual property in geographic information (i.e. copyright, other IP, and additional ownership claims based on contract or database legislation), see NRC (1999a), NRC (1999b), Onsrud and Lopez (1998), Pluijmers (1997), Silverstein (1996), Karjala (1995) and Cho (1995).

Liability issues and conflicts over responsibility for damages in the event of harms caused through the use of spatial technologies or databases are explored in Onsrud (1999), Schultz (1999), Stewart, et. al. (1997) and Phillips (1996).

Public use of and access to government geographic databases is often the test case in local jurisdictions for resolving conflicts over access to government data generally. Such cases involve complex sets of tensions between citizens, government officials, non-profit groups and the commercial sector. Access to government geographic databases and the conflicts to which they give rise are discussed in Onsrud (1998b), Onsrud (1998c) and Lopez (1996) while access to government databases in general are discussed in Weis and Backlund (1997). (See also Los Angeles (1999)).

To treat the works in geolibraries foremost as commodities harms other valuable societal functions of information. Conflicts and tensions between the “public goods” and “private commodity” aspects of geographic data in library or library-like online settings are discussed in NRC (1999c) and Onsrud (1998d).

Finally, the sale of geographic data by government agencies and the imposition of restrictions on the use of data gathered at taxpayer expense continues as a highly contentious issue in jurisdictions across the entire nation as discussed in Perritt (1995), Onsrud et. al. (1996), Onsrud (1998a), and, generally, NRC (1999a&b).

GIS Law Webcast Lectures

The following lectures were presented in SIE525 Information Systems Law at the University of Maine during the fall of 2001.  View the videos using recent free versions of Netscape and Quicktime.  Consult access, software, and hardware requirements if you have difficulties.  Streaming video lectures and accompanying slides are available on the following topics:

Liability for Geographic Data, Products and Systems  Lectures 3, 4 and 6

Ethical Issues in the Use and Development of Information Systems  Lecture 5

Privacy and the Use of GIS  Lectures 7, 8 and 9

Intellectual Property Basics  Lectures 11, 12 and 13

Database Protection and Academic Research Lecture 14

Copyright, Copyleft and Evolving Concepts  Lectures 15 and 16

Public Information: FOIA and Open Records Laws  Lectures 17 and 19

Access, Use and Ownership Issues Surrounding State and Local Government Databases  Lecture 20

Evidentiary Admissibility of GIS Products  Lecture 22

Developing a Public Library of GIScience  For the webcast, see Duke Law School Conference on the Public Domain under Subject Study Area 2.  Use recent free versions of Explorer and Real Player.  For the example referred to in the lecture, see Public Library of GIScience.

References Cited Above

Agre, Philip E. and M. Rotenburg, 1998, Technology and Privacy: The New Landscape (Cambridge: MIT Press).

Carson, C., 1997, Laser Bones: Copyright Issues Raised by the Use of Information Technology in Archaeology. Harvard Journal of Law and Technology, 10(2), 281-319.

Cho, G., 1995, Legal Dilemmas in Geographic Information: Property, Ownership and Patents. Journal of Law and Information Science, 6(2), 193

Clarke, Roger, 1999, Person-Location and Person-Tracking: Technologies, Risks, and Policy Implications. Information, Technology and People,

Curry, M.R., 1998, Digital Places (New York: Routledge).

Hernon, P. and R. Duncan, 1997, GIS and Privacy. Journal of Academic Librarianship, 23(6), 515

Karjala, D., 1995, Copyright in Electronic Maps. Jurimetrics, 35(4), 395-416.

Lopez, X., 1996, The Impact of Government Information Policy on the Dissemination of Spatial Data. PhD Diss., University of Maine.

Los Angeles Police Department vs. United Reporting Publishing, U.S. Supreme Court, No.98-678, decided Dec. 7, 1999. (State law upholding authority of local government agencies to maintain open access to public records while limiting the First Amendment rights of corporations to use government databases for commercial purposes. See also Charles L. Black, Jr., former Dean of Yale Law School, “A New Birth of Freedom” in regard to development of new human rights for citizens as superior to corporate rights)

Marx, G. T., 1998, Ethics for the New Surveillance. The Information Society, July, 14(3), 171

National Research Council (NRC), 1999a, A Question of Balance: Private Rights and the Public Interest in Scientific and Technical Databases. Committee for a Study on Promoting Access to Scientific and Technical Data for the Public Interest, Commission on Physical Sciences, Mathematics, and Applications (CPSMA) (Washington D.C.: National Academy Press).

National Research Council (NRC), 1999b, The Digital Dilemma: Intellectual Property in the Information Age. Committee on Intellectual Property Rights in the Emerging Information Infrastructure, Commission on Physical Sciences, Mathematics, and Applications (Washington D.C.: National Academy Press).

National Research Council (NRC), 1999c, Distributed Geolibraries, Panel on Distributed Geolibraries, Mapping Science Committee, Commission on Geosciences, Environment and Resources (Washington D.C.: National Academy Press).

Onsrud, H.J., 1998a, Loss of Legal Access to Geographic Information: Measuring Losses or Developing Responses? In Janelle, D.G. and D. Hodge (Eds.), Information, Place and Cyberspace: Issues in Accessibility (Berlin and Heidelberg: Springer-Verlag) 2000 – In press. 1998 version at (

Onsrud, H.J., 1998b, The Tragedy of the Information Commons. In Taylor, F. (Ed.), Policy Issues in Modern Cartography (Oxford: Elsevier Science) 141-158.

Onsrud, H.J., 1998c, Access to Geographic Information in the United States. Free accessibility of geo-information in the Netherlands, the United States, and the European Community, Proceedings, Oct 2., Delft, Netherlands, 33-41.

Onsrud, H.J., 1998d, Balancing Intellectual Property Rights and Public Goods Interests in Geolibraries. Fédération Internationales des Géomètres (FIG), Brighton England, July 25, 1998, 3, 222-226. (Based on earlier presentation to Conference on Geolibraries, Mapping Science Committee, National Research Council, June 15, 1998, Washington D.C.)

Onsrud, H.J., 1999, Liability in the Use of Geographic Systems and Geographic Data Sets. In Macquire, Goodchild, Rhind, and Longley, (Eds.), Geographic Information Systems: Principles, Techniques, Management, and Applications (New York: Wiley).

Onsrud, H.J. and X. Lopez, 1998, Intellectual Property Rights in Disseminating Digital Geographic Data, Products, and Services: Conflicts and Commonalities among European Union and United States Approaches. In Masser, Ian and Francois Salge, (Eds.), European Geographic Information Infrastructures: Opportunities and Pitfalls (London: Taylor and Francis) 153-167.

Onsrud, H.J., J. Johnson, and X. Lopez, 1994, Protecting Personal Privacy in Using Geographic Information Systems. Photogrammetric Engineering and Remote Sensing, LX(9), 1083-1095 (ESRI Award for Best Scientific Article in the Journal – 1994).

Onsrud, H.J., J. Johnson and J. Winnecki, 1996, GIS Dissemination Policy: Two Surveys and a Suggested Approach. Journal of Urban and Regional Information Systems, 8(2), 8-23.

Ontario Office of Information and Privacy Commissioner, 1997, Geographic Information Systems (April 1997)

Perritt, H., Jr., 1995, Should Local Governments Sell Local Spatial Databases Through State Monopolies? Jurimetrics, 35(4), 449-469

Phillips, J., 1996, Information Liability: The Possible Chilling Effect of Tort Claims Against Producers of Geographic Information Systems Data. Florida State University Law Review, 26(3), 743

Pluijmers, Y., 1997, Protecting Intellectual Property in Private Sector Spatial Datasets. MS Thesis. University of Maine.

Schultz, R., 1999, Application of Strict Product Liability to Aeronautical Chart Publishers. Journal of Air Law and Commerce. 64(2), 431-460.

Silverstein, M., 1996, The Copyrightability of Factual Compilations: An Interpretation of Feist Through Cases of Maps and Numbers. Annual Survey of American Law, 147-218.

Stewart, K., G. Cho and E. Clark, 1997, Geographical Information Systems and Legal Liability. Journal of Law and Information Science, 8(1), 84

U.S. Department Of Commerce, National Telecommunications and Information Administration, 1997, Privacy and Self-Regulation in the Information Age.

Weiss, P.N. and P. Backlund, 1997, International Information Policy in Conflict: Open and Unrestricted Access versus Government Commercialization. In Kahin, B. and C. Nesson, (Eds.), Borders in Cyberspace (Cambridge: MIT Press) 300-321

Whitman, D., 1999, Digital Recording of Real Estate Conveyances. John Marshall Law Review, 32(2), 227-268.

Return of Ordnance Survey’s free OS OpenData Masterclasses

Data makes the GIS world happen, good quality data is essential and FREE good quality data is rare. So when Ordnance Survey released their Open Data product it was met with a mixed review. Initially there was some disappointment that there wasn’t the full level of detail that one would expect from the Mastermap product, but then we all knew, in the back of our minds that it was never going to happen.

Over time I have grown to love the OS Open Data, it links seamlessly into so many other data and there is never a question of the data quality. Last year I got the opportunity to go to the OS Open Data Masterclass at the Ordnance Survey here in Southampton, UK. Interestingly, the class was ran using QGIS 1.8 and had hands on demonstrations, showing how the data can be used to solve spatial problems.

So, how excited was I to see this morning, that Ordnance Survey are going to run another set of classes!! Have a look below at the blog from the Ordnance Survey and book yourself a place!!

From the Ordnance Survey blog: By , 8, October, 2013 8:00 am

People across Great Britain are being given the opportunity to gain a greater understanding of open data and the tools and techniques to use open datasets, through a series of free masterclasses, hosted by Ordnance Survey and supported by Horizon Digital Economy Research.

OSOpenData masterclass icon

materclass being delivered

This series of masterclasses will follow the format of previous workshops in combining theory and practical sessions, though we have updated the workshop material, still following the same journey of downloading the data, importing it into open source software and mashing with other open datasets to provide analysis. This class is ideal for those new to working with location data or anyone wishing to brush up on their skills.

We shall also be working with OS OpenSpace, Ordnance Survey’s free web mapping service that allows users to display up-to-date Ordnance Survey mapping in a web page or online environment. The workshop for this session will explain how to create file formats that can be easily imported into web mapping to show a list of locations.

For more advanced users, we will introduce our cartographic design principles and run through how to style map data features using open source software, and add the finishing touches to their map such as legends and scales bars.

Peter ter Haar, Director of Products and Innovation at Ordnance Survey, said: “The masterclasses are a great opportunity for people to experiment and start to develop with Ordnance Survey’s open data products and services. The sessions will provide the attendees with the tools and techniques needed to use, analyse and style a range of open datasets relevant to them.

“Today we are seeing thousands of ventures, products and applications underpinned by location data, and we want to make ensure that when developers are using digital mapping they think of Ordnance Survey. Through OS OpenData and OS OpenSpace anyone can access, for free, detailed and trusted digital mapping to support their products, services or applications.”

Ordnance Survey is able to offer up to 40 places at each master class, running from 9.30 am until 5.00pm each day. Locations and dates of the sessions:

Use our OS OpenData Masterclass finder to see where the nearest one is to you, and book your place today, or click on the relevant link above to reserve your space and obtain a ticket.

open data masterclass finder

We look forward to seeing you there!

GIS Tips – Speed up ArcCatalog Start Up

Disconnect your folders!! Why?

When you open ArcCatalog, a set of entries are inserted into the Catalog tree and a complete scan of your connected folders occurs to identify files of the type you’ve instructed ArcCatalog to show. Of course, many of us may not be aware that we instructed ArcCatalog to do such a thing because we just accepted the default installation.

If you open the Options form from the Tools menu and look at the General tab you’ll see two list boxes. The first contains the top level entries you want the Catalog to contain. The second contains the types of data you want the Catalog to show. By default, all items in these two lists are selected. However, there’s a good chance that you may never need some of them. Thus, it makes sense to tell ArcCatalog to ignore entries and items that are of no interest to you by unchecking them in these lists.

In addition, there’s no sense in having ArcCatalog search for items in folders that you know will never contain GIS datasets. So, it’s a very good idea to remove the connection to the root folder of your drive from the Catalog tree along with any other connections to folders that may lead to unnecessary scanning. Then add as many connections as required to folders containing GIS data. As you should see, adopting this process can lead to a huge improvement in the speed at which ArcCatalog open

This method can also be applied to the ArcGIS desktop software also, you may notice that when you open a fresh ArcGIS session that there is the option to open the session from a large list of your connected folders.

Nick D