Azavea Atlas

Maps, geography and the web

Geolocation: Followed, Not Just on Twitter

We are truly at a tipping point in the ubiquity of geolocation technologies.

Take the browser for instance.  With the latest version of Firefox a developer can ask your permission to triangulate your location based on your IP address and the WiFi hotspot signals in your area.  Calling out to Google’s Location Services, the browser returns a reasonably accurate location to the website.   Other browsers are also working to support the Geolocation API specification — iPhone’s Safari, Opera, and Chrome using Gears.  Think of the possibilities for a dynamic localized news feed in Everyblock or highly targeted advertising.

When every website is location aware, how does this impact privacy?  Already, we are leaving a fairly large trail as we browse the web, but being able to connect to our location could be downright creepy.   The ad might read: “Hi Jeremy, care to come across the street and buy some French fries?”

The Electronic Frontier Foundation released a whitepaper this month covering the issue of locational privacy.  While I tend to think that EFF can be a bit overly cautious, they make some good points.   A lot of services can be implemented without associating a particular user with a particular location — completely anonymous search, for instance.

There are definitely uses for user specific data.   Take Loopt or Google Latitude, the entire point of the products are to publish your location to your friends.  In this regard, I don’t want the developer to jump through hoops to allow my friend to know that I am close but not reveal my actual location — it’s sort of the point.

Google Latitude on iPhone

Google Latitude on iPhone

The concept of a continuously published stream of locations for a user is immensely powerful.  Imagine if the iPhone would publish updated geo-location which was shared with applications that the user granted access.    Loopt could let me know that my friend is nearby without me having to open the application to update my location.  Zillow could pop up a notice that I’m walking by a house that is for sale that meets my requirements.   This concept of a geo-augmented reality is quite powerful, but must be done correctly so that it isn’t abused.

It will be quite interesting to see how Twitter’s API updates to include geolocation will play out.  I like the idea of using Twitter as a central location feed and having other services pull from it.   I’m sure we are going to see some location based spam start appearing — remember the French fries I was offered?

I was reading an article about ESRI’s solutions to manage GPS data for parolees.   Analyzing parolee movement is brilliant for parole officers to keep touch on what their parolees are up to.  I’d love to see a good case study in how this impacts reincarceration rates.

Contrast that with the iPhone Offender Application that was in the news.   Publishing home addresses of sex offenders is commonplace, but having extremely ready access to the data is not. How does a rehabilitated individual start fresh when i can look up the offenders on my block in 30 seconds?  Imagine the ramifications if we started publishing tracking data for parolees.  The more that you think about it the less that is different between these two scenarios, one just has more detailed data.

Yes, we are being followed more and more as geolocation becomes tied into the services we consume.  Let’s just hope its all implemented securely.    And, no, I don’t want any French fries.

ArcGIS Explorer – 5 Favorite Things

ESRI released a new version of ArcGIS Explorer a couple of weeks ago and it is a lot different from the previous version. There are more offerings in base maps, data as well as just a usable application. The following are my 5 favorite things after playing with the application.

Globe, 2D & 3/D Display

Sometimes you want things round…

Globe View

Sometimes you want things flat…

2D View

Then there are times you want a different point of view…

Oblique Perspective

Data Offerings

Built right into the interface are a number of base maps that allow you to switch between a number of ArcGIS Online map services as well as the ability to view the use Microsoft’s Bing! Maps (after registering to do so…)
Base Map Offerings

There are also a number of new data types that can be brought in locally or via the web.

Data Offerings

2007 High Resolution Aerial WMS Service hosted by New Jersey Office of GIS and a Layer Package showing the different play spots at Scudders Falls

Routing & Geocoding

Somehow or another, I always end up being the guy who has to give directions. Being the nerd that I am, I take GPS Coordinates of all the places we go paddling or mountain biking. Now I can store all of them in one place and share them (jumping the gun here, that is my next item) with friends so they can get directions from wherever they are coming from (and stop blaming me when they get lost). It uses the ArcGIS Online Routing Task Service and so far noone has gotten upset with me about the directions.

A trip we had talked about doing using previously collected GPS coordinates from a GPX file and the routing functions in ArcExplorer

A trip we had talked about doing using previously collected GPS coordinates in a GPX file and the routing functions in ArcGIS Explorer

There is also a ‘Find’ function in the application. I did a search for Ohiopyle Falls, and it dropped the pin right on it.


ESRI built the functionality to share ArcGIS Explorer maps right into the application. There are two methods, the first is bundling everything up and saving it as a Map Content File (.nmc), the second is creating the Map Content File and launching your email client to send it out the door.

Presentation Mode

When I heard about the Presentation Mode at the ESRI Business Partner Conference, I got excited. How many times have you had to update a presentation’s screenshot because the data was updated?

Aerial view of the Ohiopyle falls, a shot of Tom F. going over the falls and shot that was taken standing next to the rim of the falls.

Aerial view of the Ohiopyle falls, a shot of Tom F. going over the falls and shot that was taken standing next to the rim of the falls.

I do have to admit that it took me a little while to understand how to build the presentation. For me it wasn’t 100% obvious that to add an image, you had to put it in as a separate layer. But once I got my head around that, it was easy. There are predefined styles for the titles, easy to use image placement interface. you can download the I cannot wait to do my next presentation!

I have made the presentation file available for download, but you will need to visit ESRI’s ArcGIS Explorer site download and install ArcGIS Explorer if you don’t already have it installed.

Whitewater References

I referenced a couple of my favorite kayaking spots, the following links will take you there if you have any interest.
Tohickon Creek
Upper Gorge of the Lehigh River
Lower Gorge of the Lehigh River
Scudders Falls
Ohiopyle Falls Race
Ohiopyle Falls
The Lower Youghioheny
US National Whitewater Center
Nantahala River

Azavea Makes the Inc. Magazine’s
500 | 5000 List

Azavea was named one of the nation’s fastest-growing companies on the 2009 Inc. Magazine’s 500|5000 List at number 1,741 and ranks 52 in the Greater Philadelphia region, based on its 182.4 percent revenue growth over the past three years.


The 2009 Inc. 500|5000 serves as a unique report card on the U.S. economy.  Despite the current gloomy economic situation, the aggregate revenue among the companies on the 2009 Inc. 5000 List increased to $214 billion, up $29 billion from last year, with a median three-year growth rate of 126 percent. The Inc. 5000 are responsible for creating more than 1 million jobs since their founding, making the list perhaps the best example of the impact private, fast-growing companies can have on the economy.

This year’s list also offers a preview of which industries are poised for growth in coming years. With an average growth rate of 667 percent, Insurance ranked as the top industry overall. Government Services was the top industry gainer with 252 companies on this year’s list, up from 135 last year. Health is the top industry by both total revenue ($22.7 billion) and total employment (156,223 jobs).

After ranking 13 on the 2009 Inner City 100 List, we are thrilled to be part of the Inc. 5000 List for the first time.

Read more about the 2009 Inc. 500|5000, here.

Mappa Mundi: Mapping the Medieval World

We spend a lot of time ensuring that we have the most up-to-date and accurate geographic information. Whether it’s working on the Unified Land Records System to properly identify real estate parcels in Philadelphia or checking for any changes to political district boundaries for use in Cicero, we obviously need to have the most current data available.

Sometimes, though, it’s fun to forget about modern cartography for a minute and check out maps from the past – many of which differ radically from how we think of maps. A mappa mundi (Latin for cloth of the world) is a general term for a type of Medieval European world map. There are several kinds of mappae mundi and the features on the maps vary widely. Some illustrate only the world as it was known at the time while others include unknown or unidentified lands as well as locations from classical history, legend, or the Bible. The maps were not used as navigation tools but instead served as visual histories, teaching objects, and illustrations of religious or philosophic ways of understanding the world and what was seen as God’s creation.

Hereford Mappa Mundi from Wikimedia Commons

The Hereford Mappa Mundi from Wikimedia Commons.

Often circular in shape, the maps usually depicted a familiar, known geographic feature in the center with additional locations expanding outward. The Hereford Mappa Mundi, the largest medieval map still in existence at around 5 feet high and 4 feet 6 inches wide, features Jerusalem at the center with Egypt to the right, the Ganges River near the top of the map, and England in the lower left corner. The Sawley Map, a world map drawn circa 1190 and currently on display at the Metropolitan Museum of Art in New York, also places Jerusalem and the Mediterranean Sea at the center of the circle and includes Rome, Constantinople, Alexandria and other cities in the surrounding area. Images of angels encircle the map and Paradise is shown at the very top of the world. These maps might not be very useful for traveling, but they do serve as wonderful resources for information on medieval thought, education, culture, and the arts.

While we don’t have any spare mappae mundi hanging around the office, Azavea has done work with historic maps before. contains the Hexamer & Locher maps, which date from 1858-1860, and the AfricaMap project features several maps from the 17th and 18th centuries, including one with great illustrations of sea monsters.

Earth from Above – TED Talk

In this image-filled talk, Yann Arthus-Bertrand displays his three most recent projects on humanity and our habitat — stunning aerial photographs in his series “The Earth From Above,” personal interviews from around the globe featured in his web project “6 billion Others,” and his soon-to-be-released movie, “Home,” which documents human impact on the environment through breathtaking video.