NYC data, wide open

Posted on October 6, 2009 by Steven Romalewski

Today the NYC Mayor’s Office launched two related initiatives, a new “DataMine” website and the NYC BigApps competition.  I blogged about both items last month, and though I was skeptical then, I’m quite impressed now.

The DataMine site is big.  It lists 103 “raw” data sets (basically lists, spreadsheets, RSS feeds, that sort of thing) and 91 “geographic” data sets (data in GIS format).  There’s some overlap, and the official news release says the city is release “more than 170 city datasets.”  (See also a blog post at Flowing Data and a New York Times item in the “Bits” blog.)

The list includes everything from city bike rack locations to water fountains in parks to almost all of the city’s basemap GIS data.  Some of these GIS files were already available for free download under the City Planning Department’s “Bytes of the Big Apple” program and DoITT’s GIS Downloads site, but now they’re all in one place with everything else.

Well, not really everything else.  In my September post I noted that there are lots of agencies that all maintain lots of data sets — certainly many more than 170 — and there are few reasons the city shouldn’t be as expansive as possible in making them publicly available in a structured way.  (And the city doesn’t need a BigApps competition to do that.) 

One data set in particular that doesn’t seem to have made the list is the license-restricted, fee-based “MapPLUTO” data from the Planning Department.  It amazes me that they can still charge up to $1,500 annually for this data while all this other information is now freely available.  But I guess it’s either bureaucratic inertia or ineptitude or perhaps some small-minded administrator somewhere holds far too much power over this data.

But nonetheless I’ll say it again, I’m impressed ith the DataMine site.  And on the face of it, it seems like a sea change in how the city is thinking about data access.  Hopefully it’s also just a start, and eventually we’ll see most everything else available like it should be.  The city’s news release states that the data being posted today will

remain available for public use after the conclusion of the competition.

So there’s hope that this effort goes beyond Big Apps and will be the first step in a broader open data effort.

People may also quibble with the formats (a mix of Excel, ESRI shapefiles, ASCII text, RSS feeds, etc) and whether they’ll be a system of providing automated updates to interested users.  And a recent post by Micah Sifry argues that Mayor Bloomberg’s

vision is still based on an outdated understanding of government-as-vending-machine (we put money in as taxpayers, they deliver services) rather than a platform (we are enabled by government to connect people together around identifying problems and solutions and acting together in small and big ways).

The criticisms are valid and the debate is healthy.  If DataMine and BigApps are first steps, however, I think overall they’re good ones.  And more debate will hopefully steer the battleship that is NYC government in an even better direction regarding open data, open government, and transparency across the board.

Filed under: Data | Leave a Comment »

“Neo”, “Paleo”, “Geo”, what?

Posted on September 29, 2009 by Steven Romalewski

Just a quick note that the online journal V1 Magazine today posted an interview with me about the CUNY Mapping Service’s online mapping work.  I’m honored that Matt Ball asked to talk with me about our work — he has interviewed some pretty impressive people over the years and it’s a thrill to have our humble contributions included in the list.

We mainly talked about our experiences developing some big online mapping applications — the Long Island Index interactive map, the new version of OASIS, and an upcoming nationwide application for the 2010 Census.

I’m glad one of Matt’s takeaways from the interview is to think of our work as cutting through the debate/discussion/tempest in a teapot that’s been taking place lately about whether you’re a “neo” or “paleo” or some other type of geographer.  I can’t say that we have any definitive answers or better answers than anyone else.  But if our work helps clarify things or maybe even point the discussion in a new direction, that’d be a contribution I’m glad to make.

Btw, my slide presentation from the 2009 GeoWeb conference provides some background on how we decided on different GIS technologies/techniques for the Long Island Index mapping site.  And an earlier blog post discusses our cartographic decision-making for the new OASIS website.

Filed under: Cartography, GeoWeb | Tagged: | Leave a Comment »

Homage to the people behind OASISnyc

Posted on September 28, 2009 by Steven Romalewski

Last week’s UrbanOmnibus features an article I wrote about a new and completely revamped version of the OASIS mapping website in New York City — see “A new OASIS for New York“.  (Also see an earlier blog post about how we designed the cartography in the new OASIS maps.)

OASIS is the Open Accessible Space Information System.  The UO piece focuses on the site’s new mapping tools, richer data sets, and a new approach using “web 2.0″ techniques to encourage more interaction and engagement via the OASIS maps with urban planning in New York.

But equally impressive, though not the focus of the piece, is the part of OASIS that doesn’t directly involve mapping and web technology.  It’s the people and groups “behind the scenes” that make it all worthwhile.  Their work and the collaborative effort that OASIS has helped facilitate are really amazing.

OASIS was the vision of several people in the Forest Service (Jim Lyons, Michael Rains, Phil Rodbell, Matt Arnn, Robin Morgan to name a few), ESRI (especially Dave LaShell), and local greening organizations in New York back in late 2000.  The idea was to bring together a bunch of groups interested in sharing resources and ideas about open space stewardship, create an online mapping site to integrate all this info (way before Google Maps was on the scene), and see where that would lead.

The OASIS mapping site is powerful, but the website without the people and partnerships would just be one more (though impressive) map mashup.  The collaborative nature of the effort from the start — inspired and sustained especially by Matt Arnn — always seemed special.

Some folks who deserve special mention (though this is certainly an incomplete list) are:

  • Council on the Environment of NYC — Lenny Librizzi at CENYC is absolutely wonderful, and has a great vision of involving students and community groups in the greening of the city.  He trains high school youth to inventory street trees in a way that teaches ecology, math, science, and urban planning in an engaging way.  He’s also led the effort to map community gardens across the city, maintaining a comprehensive database of gardens for analysis, advocacy, and teaching.  It’s been great working with Lenny as we’ve integrated all that data into OASIS.  The maps are powerful, but in some ways it’s more important that they’ve been a vehicle to get to know him and to give his students invaluable hands-on experiences.
  • Open Road of New York  — Paula Hewitt Amram is an inspiration to untold numbers of city youth who want to change the world or are just looking for a better spot to play in.  (Here’s an example: Amy Poehler interviewing 11-year old Valentine about her community gardening work at Open Road.)  She’s brought that energy and spirit to the groups involved in OASIS, with a real passion for wanting the collaborative effort to endure so it will continue to be an educational and participatory resource. 
  • The greening groups involved in GROW (Grassroots Reassuring OASIS Works) – they coordinated a series of focus groups early on to make sure that whatever online mapping tools were created, were developed with an eye toward the neighborhood organizations and activists who needed the information the most.  Their insights continue to resonate with the OASIS participants, even as the GROW coordinators Wendy Brawer and Hugh Hogan have gone on to do other amazing things.
  • The Forest Service team at its Northern Research Station – Erika Svendsen has consistently pointed out that maps of buildings and park boundaries are nice, but maps also need to convey a sense of who’s doing what where: the people and their activities in any given geographic area are obviously and critically important.  This interest enhanced the Forest Service’s Living Memorials Project, and simultaneously was a key theme in discussions among OASIS participants about the need to understand local environmental stewardship (who’s doing what environmental work where).  Eventually Erika, Lindsay Campbell, and the Forest Service’s NYC Urban Field Station turned this concept into reality with the unique Stewardship Mapping and Assessment Project (STEW-MAP).  Erika and Lindsay and their colleagues provide a refreshing perspective to us online cartographers, and hopefully this will also become obvious to anyone using the new OASIS maps when they view the STEW-MAP “turfs” that are displayed.
  • ESRI – Dave LaShell helped develop OASIS early on and has been a consistent booster.  Though Dave works for a software company, I think in another life he’d be an environmental and community organizing visionary. ESRI has provided substantial software and technical support resources to OASIS from the beginning.  But Dave always saw far beyond that, understanding intuitively that bringing people together was the important thing, not any particular technology or software package these people happened to be using.  He also does that in his ongoing efforts at ESRI’s NYC office, and in extracurricular work — for example, he volunteers with the Academy for Urban Planning, which has the only high school level GIS program in the city.  Dave epitomizes what I said about ESRI when Matt Arnn and I accepted the Municipal Art Society’s “Certificate of Merit” award for OASIS in 2001, that it’s a private company with a public conscience.
  • Individuals like Jane Sokolow, Bob Alpern, and Jack Eichenbaum – I’ve known Bob and Jack for years, and more recently Jane, and it’s been wonderful and enriching working with them together on OASIS.  Also, my colleague Christy Spielman was involved with OASIS at the start, designing the maps and managing the data and website.  But she’s been critical at coordinating and facilitating the various organizational partnerships that have developed through OASIS; those contributions have been as important as her GIS & graphic design skills.  And Dave Burgoon, who’s a dream to work with, has used his programming skills to make the new OASIS website worthy of this recent praise from a financial blogger at Reuters: “This is the most amazing map of NYC I’ve ever played with. Just, wow.”
  • Last but not least, the Forest Service itself.  When I first heard that the Forest Service was convening a meeting in 2000 to talk about mapping the city’s “urban canopy” (i.e., trees), I was skeptical.  I was most familiar with their work managing land in the western US or fighting forest fires, not working in cities, let alone New York.  But even then they had developed a strong argument for caring about trees and open spaces in urban areas – both for environmental reasons as well as for the ability to relatively easily engage large numbers of people in these densely populated areas.  Phil, Matt, Robin, et al. provided great and consistent support for OASIS in its early years and still value the benefits that this collaborative effort has provided.  It’s been terrific getting to know them and work with them.

Of course there are too many people and groups to mention in detail, so please visit the OASIS participants page to see the full list.  (And even on that page we’ve probably missed a few.) 

Although active participation in the steering committee has ebbed and flowed (it’s probably at a low point at the moment, with most of the effort going toward the website redesign), you can still get involved.  Here are some links with more info:

All in all, OASIS has made its impact felt – in me and my professional and personal relationships, in the work of many people and groups across the city, and hopefully beyond all that to the city and metropolitan region at large.  I’m thrilled to have had the opportunity to have been (and to continue to be) a part of it all.

Filed under: GeoWeb | Tagged: , , , | Leave a Comment »

Opening up access to NYC data?

Posted on September 2, 2009 by Steven Romalewski

This week I submitted our recommendations [PDF] for data sets to include in New York City’s “Big Apps” competition.  September 1 was the deadline for data ideas, and also for responses to the RFP to run the competition itself.

I was a bit surprised by the city’s announcment in June about Big Apps, because I know painfully well how tight-fisted the city’s agencies can be with their data.  (For example, I have helped sue city officials to turn over data, and have written more FOIL request letters than I can count.)  Some agencies have opened up in recent years, but many still cling to outmoded thinking about “their” data and wanting to control it and prevent people from accessing it.

But as I thought more about BigApps, it seems to be as much about leveraging economic development as it is about access to data.  The announcement itself talks about transparency & open government, but this is in the context of “encourag[ing] the public to develop applications” rather than data access as a good thing on its own.  In Washington, DC — the model for New York’s Big Apps competition — the data was made available first, and the competition came second.  New York is doing it the other way around.

So I submitted my comments hoping for the best, but realizing that important questions still remain:

  • Will the city provide full data sets, or just excerpts for prototype apps?
  • Will all agencies participate, or just some? (The city’s news release talked about 80 data sets from just 32 agencies, but that’s just the tip of the iceberg – see below.)
  • Will data be available just for app developers, or for anyone (or any entity)?
  • If no one writes an app for a specific data set, will the city continue making that data set accessible?
  • What about data that might be used to criticize government efforts (eg, inadequate buildings inspections or complaints that haven’t been addressed)?

Also, the city is just one player (though a big one) in the game.  Many state and federal agencies have already opened up their data.  But others, such as the Metropolitan Transit Authority – a public authority (not under the mayor’s control, or anyone else’s, some might say), are still fighting open access to their key data sets.  In order to give the public a complete data picture, we need to make sure all levels of government become transparent.

Nonetheless, it’s great to see the growing interest in opening up access to city data.  The city’s BigApps announcement has re-focused attention on the issue, there are several sites now dedicated to it, and the City Council is considering legislation along these lines.  And New York is just the latest city to move in this direction, following Washington DC, Boston, and San Francisco (and perhaps others I’m not aware of).  It’s easy to say that open data initiatives should’ve/could’ve been implemented much sooner (for example, my BigApps submission includes a summary of a 1999 white paper I co-authored laying out a framework for public access to municipal data).  But the advent of all the impressive open source technologies and mobile apps have captured the public’s imagination so that even hardened city officials can’t ignore the push in this direction.  So hopefully some good will come of it.

My submission referenced a 2001 inventory of NYC data systems [PDF] as an example of virtually all city agencies maintaining computerized data which can & should be publicly accessible.  Most of these (in 2001) were mainframe apps and have now likely been subsumed in other systems or initiatives (such as 311).  But given the glacial pace of (technological) change in municipal government, I wouldn’t be surprised if some of these systems are still around.  And the data in them certainly still exists.  And, by and large, the regulatory programs that created them in the first place are still around. 

nyc2001datainventory

Aside from its age, the 2001 inventory should provide a helpful road map for what data we might reasonably ask the city to make available.  Hopefully people will use this information constructively and persuasively toward that end.

Btw, my BigApps recommendations didn’t focus so much on GIS data as it did on other interesting data sets.  New York definitely needs to do a better job about access to its GIS data — many agencies don’t publicize or make it obvious how to access their GIS data.  But the two main repositories of GIS data sets (DoITT and the Dept of City Planning) already do a pretty good job about making people aware of downloadable GIS data and providing access to it. 

But I did focus part of my comments on the untenable license restrictions and fees charged by City Planning for its “MapPLUTO” data — GIS layers combining tax parcel boundaries with detailed property information. 

mappluto

True, the Planning Dept puts time and effort into aggregating several sources of property data into PLUTO.  But they’ve already done so much to remove fees for other GIS layers such as the street grid (the LION file) and district boundaries — why stop there?  Unfortunately they have monopoly control over the data, so even we pay the fees, but it flies in the face of the Mayor’s Big Apps announcement, so hopefully Big Apps will finally force City Planning to see the light when it comes to PLUTO.

Filed under: Data | Tagged: | 5 Comments »

Manhattan’s daytime population: map source found!

Posted on August 22, 2009 by Steven Romalewski

This post starts with an exploration of what happens when bloggers don’t source their material (in this case, maps), but ends with a cool discovery of a resource for all you dasymetric mappers out there (you know who you are).

Earlier this month my wife forwarded me a link to a Gothamist Map of the Day — see below.

newyorkdaynight

The map is interesting (though somewhat problematic) in several ways.  But what struck me about it is that: 1) I definitely had seen it before, but 2) there was no attribution at Gothamist – no indication of what time period the map covered, who made it, the source of the data, etc.  So, a cool map, but zero context and no way to verify it or really understand what the map was telling us.

Sure there was a link to the “source” — but this just took me to Buzzfeed, where someone had posted the map, also with zero attribution or any other context.  (One of the commenters at Buzzfeed says that “this is the most frustrating thing about buzzfeed— they fail to attribute a lot of stuff properly.”  Someone responded to this commenter noting that “it is annoying sometimes [providing no attribution], especially with stuff like this chart which is supposedly based on some facts” (my emphasis).

Another commenter at Buzzfeed has a link to doobybrain.com which claimed the map (or, “infographic” as doobybrain described it) was from a 2007 issue of Time Magazine, though the source for the doobybrain item was another blog post.  (In the world of web anonymity, the doobybrain source is misterstarfish.typepad.com from haj718(at)mac(dot)com .)  Alas, misterstarfish/haj718 offers no attribution or context either.

I looked around a bit on Google and Bing to see what I could find, but didn’t turn up any other useful references (I found a few other blogs and graphics sites that had re-posted the map, but no details).  I even commented on the Buzzfeed piece, but no one responded with more info.

Then I happened to have a conversation last week with the director of Urban Omnibus, an online project facilitating a conversation about New York’s architecture, planning, development, and all things urban.  He mentioned in passing the “map” tag on his site, I clicked it, and struck gold.  Earlier this year (March 2009), Urban Omnibus published an interview with Joe Lertola titled “Let’s Talk About Maps 2″ (the first installment of Let’s Talk About … being an intro to the column).  The interview highlighted Lertola’s work at several publications, including Time Magazine, and of course included the “Day and Night Population” map along with a brief description from Joe.  Mystery solved! … mostly.

I needed to visit Lertola’s website directly to find out more, and it turns out he did create this map for Time in 2007 (the Nov. 26, 2007 issue, to be exact – click the “City Population Shift” tab).  But it was part of an overall layout that highlighted portions of several cities across the US, and the “NYC” graphic was just an inset of a larger graphic — which is why it only focuses on lower Manhattan (not all of New York City, as several blog commenters pointed out).

But even Lertola’s website and Time itself didn’t provide more precise details on the data source.  The original Time piece lists the sources as:

Census Bureau, Bureau of Labor Statistics; Texas Transportation Institute; Oak Ridge National Laboratory/UT-Battelle LLC.

Lertola’s website goes a bit further, noting that:

the Geographic Information Science and Technology group at Oak Ridge National Laboratory has developed LandScan USA, the most detailed population model available.  By integrating Census data with extensive information on other daily activities, LandScan can predict the population of any U.S. location at any time of day.

Aha, a searchable term – LandScan!  It didn’t tell me data vintage or anything like that, but at least I can go to the source.  And the results are intriguing.  The LandScan website states that

LandScan USA is more spatially refined than the resolution of block-level census data and includes demographic attributes (age, sex, race). The model includes development of an “ambient population” (average over 24 hours) for global LandScan and development of spatial distributions for “residential or nighttime population” as well as for “daytime population” as part of LandScan USA. Locating daytime populations requires not only census data, but data on places of work, journey to work, and other mobility factors. The combination of both residential and daytime populations will provide the best estimate of who is potentially exposed to ambient pollutants.

In other words, the data claims to address two interesting GIS issues related to demographic analysis: dasymetric mapping (modeling population patterns for smaller areas than typical Census geography, which allocates population across an entire tract, say, regardless of where people actually live within that tract) and daytime population (Census population data correspond spatially to where people live — i.e., the population at night — rather than where people work or shop – i.e., the population during the day).  Each of these issues is compelling for a variety of policy areas, spatial analysis theory and practice, and creating cool maps.

Needless to say I’ll be emailing the keepers of the data (Oak Ridge National Lab at LandScanTechnical@ornl.gov) to find out more.  If anyone has any other leads, please let me know.

Filed under: Cartography, Spatial analysis | 7 Comments »

Mapping “hard to count” areas for 2010 Census

Posted on August 19, 2009 by Steven Romalewski

UPDATED 8/21/09: Newsday (Long Island’s daily newspaper) reproduced an island-wide version of one of our maps in their article today (though the map only appeared in the print version of the paper).

People are gearing up across the US for the 2010 Census — not just the Census Bureau, of course, but organizations large and small who are planning myriad outreach efforts to boost participation, especially in typically “undercounted” communities.

It’s important in so many ways for everyone to be counted, but historically not everyone is (and not just because of statistical anomalies or poor street address data).  For various reasons, key constituencies are not fully counted — people of color, renters, recent immigrants, people predominantly speaking languages other than English, etc.  There’s a special effort underway – supported by major foundations, local governments, and spearheaded by advocacy and civil rights groups - to make sure the Census Bureau doesn’t miss these ”hard to count” groups.

Our teamat the Center for Urban Research, CUNY Graduate Center is doing its part by mapping the “hard to count” (HTC) population in more than two dozen metropolitan areas nationwide, with the support of the Hagedorn Foundation.  We’ll also be developing an online, interactive mapping application for funders, outreach groups, local officials, the media, and others to easily zoom in on their metro region and create custom maps to help focus their efforts.

Where are the hard-to-count communities?  The Census Bureau analyzed 2000 Census data to:

measure census coverage and to identify reasons people are missed in the census (de la Puente, 1993). The variables include housing indicators (percent renters, multi-units, crowded housing, lack of telephones, vacancy) and person indicators (poverty, not high school graduate, unemployed, complex households, mobility, language isolation).

From this, the Bureau calculated an HTC score for each tract in the nation (on a scale of 0 to 125).  They estimate that any tract with a score of 60 or higher will be at the greatest risk of undercount in 2010.  Our metro maps for the 2010 outreach campaign highlight the concentrations of HTC tracts, as well as the 2000 Census response rate by tract.  Here are two examples, for Chicago and New York City:

Chicago_HTC_2010Census

NYC_HTC_2010Census

Foundations are using these maps to help guide their grantmaking, and local groups are using the maps to target their outreach.  As an example, this month several Long Island-based foundations issued an RFPfor grants to local groups doing Census outreach.  The Hagedorn Foundation asked us to create a special set of Long Island maps to supplement the RFP – you can view the PDFs here and here(see below for a sample – these mapped the HTC scores relative to all tracts in Nassau, so some tracts with scores less than 60 — but still harder to count than others in the county — are shaded as hard to count).

Nassau_HTC_2010Census

Next step for us is to transform these printed maps into a nationwide online mapping website.  The site will enable people to: 

  1. Zoom to their neighborhood, county, city, or state to see the mapped patterns of hard-to-count Census tracts;
  2. Click on individual Census tracts to display detailed information about each one;
  3. Add other layers of Census demographics, 2000 Census response rates, related data from the 2005-07 American Community Survey, and recent foreclosure risks circa 2007-08 so people can see the interrelationships among multiple variables; and
  4. Display state- and local-level resources such as funding opportunities, regional Census contacts, contact info for groups participating in Census outreach, etc.  

We’ve been reviewing other projects that are similar so we don’t duplicate efforts.  These include:

A key question for us is which basemap do we use?  We’ll be serving the tract-level geography and attributes (probably as cached tiles) from our servers using ArcGIS Server on the backend, OpenLayers and ExtJS on the front end — a combination that has served us well (see here and here).  Likely we’ll use Google Maps (and/or their Hybrid or Terrain views) for the underlying street/reference geography.  But perhaps OpenStreetMap would be a better choice?  Or Bing Maps?  Advice from the GeoWeb community would be appreciated.

Timing? We’re shooting for a beta site in late September, seeking feedback from partner groups in the fall, and a production-level site by the end of the year.

Filed under: Cartography | Tagged: , , | Leave a Comment »

Online cartography for richly layered maps

Posted on August 12, 2009 by Steven Romalewski

Several recent items have called attention to the growing effort to make really good-looking maps online – see Matt Ball on the coming “cartographic explosion” and Peter Batty’s posts highlighting the great maps from OSM and CloudMade and of course Stamen Design (hardly an inclusive list, but it’s already a long-ish intro sentence).

It’s an exciting time for all that.  We’re hopefully moving well beyond the ubiquitous pushpins of more map mashups than we can count (no dig against Google Maps, but the pushpins can get a bit old — see EveryBlock’s insightful post about “Google Maps fatigue“ and FortiusOne’s original — and on-the-mark — blog title “Moving Past Pushpins“). 

From what I can see, however, most of the latest online cartography efforts are focused on road-centric basemaps.  This is great, but there’s a lot more mapped information out there that eventually will be either layered on top of these basemaps or provided online directly.  And we’ll need good cartography to display richly layered online maps effectively.

I wanted to add a note about our humble contribution to that effort.  Our team at the City University of New York (and earlier at the Community Mapping Assistance Project, CMAP) has maintained an online mapping platform for the New York area since early 2001 called OASIS — the Open Accessible Space Information System.  OASIS displays open space resources (broadly defined) to help sustain these resources and visualize the nexus between community greening and broader urban planning issues.  The project is guided by a collaborative partnership of almost 60 greening groups, educators, individuals, businesses, nonprofits, and public agencies.

oasis_mainview

We recently completely revamped the website (see above screen shot).  The old site is at www.oasisnyc.net.  The new one is at http://www.urbanresearchmaps.org/oasis/map.aspx (best viewed in Firefox but tested in IE 6 & 7, Chrome, and Safari).  Our cartographic challenge — as Christy Spielman, a long-time colleague who helped create the original version of OASIS, noted — was to create an interactive map that certainly included transportation features, but in a way that kept them in the background while emphasizing parks, gardens, housing, land use patterns, zoning, schools, and more – plus aerial imagery.

Also, the recent upgrade includes neat new data such as local environmental stewardship “turfs” (in partnership with the USDA Forest Service) and *very* historical imagery and data from the Wildlife Conservation Society’s Mannahatta Project — photorealistic imagery of Manhattan circa 1609 as well as layers representing eco-systems, soils, Native American trails, and the 1609 Manhattan shoreline (more on Mannahatta in a separate post — it’s an amazing project). 

oasis_cityhall1609

So we needed to figure out styles and colors and scale dependency that would work together (we have easily more than 4 dozen layers with distinct map styles), allow room for more layers of data in the future, and potentially be able to integrate data feeds and user generated data on the fly.

I think we did ok, though there’s always room for improvement (feedback is welcome!).  Christy (and I, though to a lesser extent) spent many hours developing color styles and symbology to find the right ones that worked well together.  We used ArcGIS to develop the maps (we’re most familiar with that, and it was quicker than having to learn SLD customization, for example).  We relied heavily on ColorBrewer, an amazing resource for GIS color symbology. 

ESRI’s New York City office — in particular, Patrick Gahagan – also helped us by providing ArcGIS techniques to create the map of subway stations and routes, and providing a DEM mosaic that we used as a backdrop for the new OASIS map.

oasis_subways_and_dem

Cached tiles were key, but deciding which layers to cache and which ones to be dynamic was an involved process.  We wanted to preserve as much flexibility for the map user while of course trying to speed up performance.  We ended up caching most of the transportation data (with the option to turn on/off the entire transporation cache layer) as well as the land use information – lot boundaries, building footprints, and parcel-by-parcel color shading. 

oasis_transportationcachelayer

The parcel and building footprint layers were the most cumbersome as dynamic layers, each of them with literally a million features, so the performance gain by caching them was huge.  But Dave Burgoon (who coded the site from top to bottom – more on his impressive work in a separate post) customized the “land use” section of the legend to enable our users to display either the entire cached land use layer or to display each land use category dynamically (see screen shot below). 

oasis_landuseoptions

This was a good compromise between performance (showing all land use patterns at all scales) and user flexibility (showing one land use category at a time dynamically isn’t too slow, and enables people to see all the commercial property versus residential versus industrial at a time).

The tiles, btw, were generated with ArcGIS Server and integrated into the map directly via OpenLayers.

We also took a page from the O’Reilly book “Designing Web Interfaces” plus Axismaps (who helped design GeoCommons Maker!) plus MapTube – and created a “dynamic transparency” tool that can accomodate each map layer on OASIS. 

oasis_transparencytool

The ExtJS transparency tool allows for a smooth, real-time transition as you slide from fully opaque to 100% transparent.  It makes for a powerful user experience.  The relevant quote from Designing Web Interfaces …

Things move smoothly in the real world.  They do not “pop up”.  Transitions smooth out the jarring world of the Web, making changes appear more natural. (p. 233)

… and from Axismaps:

The transparency control lets mapmakers decide what works and what doesn’t.

Hopefully the cartographic result works well.  We’d love to know what you think!

Filed under: Cartography | Tagged: , , | 2 Comments »

Twittering observations

Posted on August 11, 2009 by Steven Romalewski

I attended the GeoWeb 2009 conference and one of my “takeaways” didn’t have anything to do with geography or the geoweb at all (directly, anyway).

I noticed that at each session, some dozen or so attendees were typing away at their laptops or iPhones.  I assumed they were just taking notes, but when I peered closer over their shoulder(s) I realized they were tweeting.  I had my new Palm Pre with me, and had signed up a few weeks before for a Twitter account, so I investigated further.  (At the time I was using the @oasisnycmaps handle, though I’ve added another one since then — and maybe there’ll be more, read on!)

Each of them were adding the #geoweb or #geoweb2009 hashtags to their tweets, so I could easily search and see all of the commentary.  Mainly they were posting comments about whatever session they happened to be attending.  But then they were also commenting on each other’s tweets, retweeting, and posting detailed feedback (like Anthony Beck’s neat MindMaps).  It was a multi-way, simultaneous, interactive, Twitter-ized conversation among attendees across different sessions and even in the same session.  Cool.

Btw, my sense of Twitter vs. FB/FF, given the recent acquisition, is that it’s somewhat apples and oranges.  To me (relative newbie), Facebook is “personal social” (updates on all manner of personal idiosyncracies) while Twitter is more apt for “professional social”, based on my experience at GeoWeb and since then following people in my professional space.

Anyway, I’m hooked.  I’ve added a Twitter handle (SR_spatial — though maybe I’ll drop the underscore, that seems to be the conventional wisdom) and started a blog (this one!).  Looking forward to diving into this brave new virtual world (but with quite tangible utility in the real one).

Filed under: Social networking | Tagged: , | Leave a Comment »