new jersey geographer » Technology

ArcGIS available on the iPhone

John Reiser — Tue, 06 Jul 2010 14:34:04 +0000

ArcGIS on the iPhone

ESRI has released ArcGIS for iPhone. It’s now available through the App Store. It’s an iPad/iPhone app, so it should work well on both. I just tried it out on my iPhone, and it’s pretty snappy. The data loads quickly and the interface is clean. There are many layers already available through the app, such as OpenStreetMap.

I like the support for ArcGIS Server, as we will be able to provide our local data to iPhone users. I hope that a later revision will also support WMS, as there are many more free and useful WMS-based services out there than ArcGIS services. Greater support for GPS would be useful. ArcGIS for iPhone can locate you using the embedded GPS, but I don’t believe you can use the GPS to record features. I believe these features will come. James Fee points out that ESRI’s response to the UC FAQ regarding iOS support is positive, claiming that updates will feature editing and geoprocessing. As much as I prefer to edit on a big, widescreen monitor, it would be nice to update my data on the go.

If you have an iPhone or iPad, download it for free from the App Store and check it out.

© John Reiser for new jersey geographer, 2010. | Permalink | One comment | Add to del.icio.us
Post tags: App Store, ArcGIS, ESRI, iPhone, OpenStreetMap

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Projects featured on Rowan’s home page

John Reiser — Tue, 06 Jul 2010 00:59:37 +0000

I’m proud to say that I now have two articles written about my work that have been featured on the Rowan University home page.

Most recently, Mapping the Guard (still on the home page) was posted, detailing the great work performed by students for the New Jersey National Guard. I’m very pleased to be heading up this internship program, because I feel that the students leaving the program will be excellent candidates for GIS positions. The students are learning about SDSFIE and other data schema, how to edit data in a multi-user environment, and working with web-based GIS services.

Way back when I was still an adjunct, Mapping the Campus in Layers was written. It’s a good read, because now that I’m at the University full time, I’ve worked to put the pieces together so that we can do much more.

Check back within two weeks about one of the projects we’re working on now. It might not be front-page material, but I’m sure you’ll find it interesting.

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Post tags: ArcGIS, Internship, Mapping, Rowan University, SDSFIE, Web Mapping

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More on Apple’s mishandling of geotagged photos

John Reiser — Mon, 05 Jul 2010 22:02:11 +0000

In my previous post, I claimed that iPhoto was the culprit behind the mangling of the GPS coordinates embedded in my photographs. The problem likely lies in the Core Image library used throughout Mac OS X.
To see if other image editing applications exhibited the same geotagging flaw, I used a jpg right off of my camera and rotated and saved it in Preview, Apple’s default image viewer. This demonstration shows that the method used to write .jpg files alters the GPS coordinates stored in the EXIF metadata.(...)
Read the rest of More on Apple’s mishandling of geotagged photos (295 words)

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Post tags: Apple, geotag, gps, Mac OS X, photos

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Apple iPhoto rounds GPS coordinates to nearest second

John Reiser — Sun, 30 May 2010 03:33:02 +0000

I’ve been working with geotagged photos for the last few weeks as part of our GIS Internship Program with the NJ National Guard. One aspect of our data gathering at each of the state’s Readiness Centers is to photo-document the site as we collect data. All of the data recorded for the facility is stored in a SDSFIE-compliant geodatabase. One of the thousands of SDSFIE entity classes used to organize the data is “photograph_location_point” – a schema specifically for recording geotagged photographs.

We recently conducted field work at the installation in Woodstown, NJ and I took along my Nikon Coolpix p6000 – with integrated GPS. Since I’ve gotten the camera, I’ve been taking plenty of pictures with it and have been pleased with the results. The pictures are of a great quality and the GPS coordinates are usually in the 1-10m range. I took about 150 pictures while the students were collecting data. Using my mobile office, I downloaded the photos into iPhoto so we could discuss the work being done. I exported the pictures from iPhoto using the Export functionality and saved them to our workgroup server.

"Rounded" and raw positions of geocoded photos.

This past week I’ve been working on a Python script* to take a directory of geotagged photographs and produce a point shapefile with the location of each picture and a path link back to the source photograph. I tested the script out on my Woodstown pictures and was conflicted: I was happy the script was doing what I wanted, but I was very disappointed with the results. It seems like the geotagged photo points were all snapped to some imaginary grid. In fact, they were! iPhoto’s export function apparently rounds the seconds value (of degrees, minutes, seconds of latitude or longitude) to the nearest whole number. In doing so, it essentially snaps all of the coordinates to a grid with a spacing of 1 second, or around 100 feet. This clearly is a problem, as the most GPS units today are much more precise. The image at left demonstrates the difference between photos exported from iPhoto and the original images from the camera. Green squares represent the point shapefile based on the exported-from-iPhoto images and the blue circles represent the unaltered images. Except for two or so misplaced points, the blue circles accurately represent my position when taking the photograph within 15 feet.

Measuring the distance.

Measuring the distances between the rounded points clearly shows that the location information is improperly exported from iPhoto and the coordinates are being rounded. iPhoto does not by default include GPS Exif tags in exported images, presumably to preserve privacy. Regardless, if the “Export Location Information” checkbox is checked, why should iPhoto even touch the GPS info? I would think it should pass the Exif tags along without molestation.

I really hope that this is a bug on Apple’s part and that they don’t assume that integer seconds ought to be enough for anybody. Until they do fix the bug, we won’t be able to edit our photos using iPhoto and retain accurate coordinates.

* I intended to release the script this weekend, but realized that I did not include any documentation in the ArcToolbox file. Once I add some documentation to the tool, I’ll put the script online and add links to this post.

© John Reiser for new jersey geographer, 2010. | Permalink | 4 comments | Add to del.icio.us
Post tags: Apple, geotagging, iPhoto, National Guard, SDSFIE

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Geotagging a short bike ride

John Reiser — Sun, 07 Mar 2010 21:44:22 +0000

Alcyon Lake

Brought my Blackberry with me on a bike ride around Glassboro and Pitman. I used beGPS One, a Blackberry GPS logging application to record my location every 30 seconds as an NMEA sentence. I then used GPSBabel to covert the file to KML format. You can view the KML of my route here. I also took the geotagged picture of Alcyon Lake at right. Finally, tweets during the trip are also geotagged.

Most of the information we deal with daily (or in this case, generate) has some geospatial component. Why not explicitly recognize the route I took or the places I photographed? Sure, some will feel that geotagging could be abused, but both Twitter and Flickr require you to explicitly allow geotagged information to be shown to other users. Facebook strips out geotagged information from uploaded photos. If there’s no real privacy concerns, you should share your pictures and tweets tagged with geographic coordinates.

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Post tags: Flickr, geotagging, gps, Twitter

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Equality in Data: Should personal addresses be redacted?

John Reiser — Fri, 19 Feb 2010 14:58:21 +0000

The property of a randomly chosen "John Smith"

Mecklenburg County (Charlotte), North Carolina is currently facing an information-sharing predicament. POLARIS, their county-wide interactive web map, currently serves up property ownership information as part of the real property and tax records in the county databases. The county is looking to remove the ability to search by owner to locate land records, mainly because the police are concerned that criminals may use the system to target officers’ homes. I appreciate the concern for the safety of the police force, however theoretically anyone could target anyone else using public records. Just because you have a hammer doesn’t mean you’re going to start hitting people with it. Intentionally crippling a web service and reducing accessibility should always be seen as a major step backwards.(...)
Read the rest of Equality in Data: Should personal addresses be redacted? (170 words)

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Post tags: FOIA, Internet, Mecklenburg County, North Carolina, opra, Privacy

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Please Rob Me: What’s the big deal?

John Reiser — Thu, 18 Feb 2010 17:36:51 +0000

There’s been a flurry of posts across the web about Please Rob Me, a site that aggregates check-ins on sites like FourSquare, illustrating the fact that we’ve known all along: people are willing to release more information than they realize. Outrage follows once the fact that technology allows information to be easily aggregated and distributed is demonstrated like this. (...)
Read the rest of Please Rob Me: What’s the big deal? (142 words)

© John Reiser for new jersey geographer, 2010. | Permalink | One comment | Add to del.icio.us
Post tags: foursquare, GIS, Privacy, social networking

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Presentation on OS GIS at MAC URISA

John Reiser — Wed, 13 May 2009 16:02:48 +0000

Yesterday, I gave an introduction to open source GIS at MAC URISA. As the meeting was about Internet-enabled GIS, I focused on server-side software. I’ve made the presentation available on SlideShare and available as a download from my website.

Here’s a listing of the programs and standards I reference in the presentation:

Here’s the sites I referenced as examples using open source GIS:

© John Reiser for new jersey geographer, 2009. | Permalink | One comment | Add to del.icio.us
Post tags: open source, Presentation, Web Mapping

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Fun with Google Latitude

John Reiser — Sat, 07 Mar 2009 01:04:42 +0000

Kate was tracking my progress home tonight, as I was going to pick up Thai food along the way. I manually set my location to “Thailand” and found when I got home, Kate was very confused as to where I was. Setting my location to “Thailand” actually set me as being in “Nong Chaeng,” which I assume is the closest place name to Google’s center point for Thailand.

When will Google release an API for Latitude? It should also tie into OpenSocial, like how iGoogle and Orkut do now. Google has been really great in releasing new and innovative social networking components and applications, but they need to really follow through and support their creations. Offer up an API and the community will do the rest.

© John Reiser for new jersey geographer, 2009. | Permalink | One comment | Add to del.icio.us
Post tags: Google Latitude, Location-based Services, social networking

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Southwest Florida

John Reiser — Mon, 09 Feb 2009 14:25:01 +0000

Kate and I are down in Southwest Florida visiting her family. We drove down from New Jersey and used Google Latitude to share our location with her family and my parents. Kate and I also are taking some pictures using my GPS-enabled BlackBerry and are posting them on Flickr.

There probably won’t be many updates to NJ Geo and NJ State Atlas until I come back up next week.

© John Reiser for new jersey geographer, 2009. | Permalink | No comment | Add to del.icio.us
Post tags: Flickr, Florida, geotagging, Google Latitude, Southwest Florida, Travel

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