Dataset of the Day: Chengdu, China Earthquake

May 30th, 2008by Brendan Lewis

Over two weeks have passed since the 7.9 magnitude earthquake devastated Chengdu, China. The end of this tragedy is still hiding as aftershocks continue to ripple throughout the country. News feeds continue to stream from China as the recovery process continues. The most recent reports have the death toll climbing to 50,000.

The USGS keeps daily records of recorded earthquakes worldwide, and enables us to pinpoint earthquake locations by providing latitude and longitude coordinates. Within Finder we have made this data available for use in shape, kml, and CSV formats to the public.

The following Datasets can be found on Finder, and can be used to gain a spatial perspective on the current events in China.

USGS, M 1+ Earthquakes, World, 5.5.08 through 5.12.08
USGS, M 1+ earthquakes, World, 5.12.08 through 5.19.08
USGS, M 1+ earthquakes, World, 5.20.08 through 5.27.08
USGS, Earthquake Records, World, 1998-2007

Popularity: 19% [?]

Links List 5.16.08

May 16th, 2008by Sean Gorman

Mashable reports that Google Maps features a new API that has flash graphics that can be used for each title layer, maker and information windows. This means you can create more dynamic map mashups.

Not only does Google Maps have flash graphics, but they have also added the ability for video sharing, Wikipedia entries, real estate listings, and geo-coded photos.

Google Earth and David Rumsey have formed a relationship where historical map collections are available through a Google Earth layer. More data means more mashups!

Interesting how Where 2.0 has a Twitter account that wasn’t followed nearly as much as it should have been.

All Points Blog also provides a “plain-English” explanation of the Google / ESRI announcement.

Popularity: 23% [?]

Virtual Earth vs. Google MyMaps KML Support

April 26th, 2008by Sean Gorman

As we’ve been putting GeoCommons through its paces I’ve been testing KML files we generate in different applications. The most interesting comparison by far has been between Virtual Earth and Google MyMaps. I did a high level comparison of the two plus Yahoo! MapMixer a few blog posts back, but after testing several KML files in each I thought it would make for a good follow up. Especially after Michael Jones’ comments to James Fee’s post about KML being the HTML of the GeoWeb.

The good news is that both Virtual Earth and Google Maps support KML, and we are seeing a greater number of applications supporting it and GeoRSS as GeoWeb standards. As the standards get picked up it will be interesting to see how they are supported and how applications differentiate themselves in doing so. Already we can see this beginning between the two titans (Microsoft and Google) expressing how their support of KML has advantages over the other. So, I thought I’d share what our experience was testing with both applications.

Google KML Support

For testing purposes I started off with a polygon data set of the 100 most polluted counties in the United States. The upload process for Google MyMaps was straight forward and my uploaded KML (or GeoRSS) file prepopulated a title and description field. Then after a bit of chugging rendered the KML file on the map. You can see the map I created embedded below:


View Larger Map

If you look closely you’ll notice that there are not 100 counties on the map (only about 44). Google MyMaps will support 200 pushpins on a map, but when you add in complex polygons the number of polygons and associated pushpins it will support goes down significantly. In the MyMaps application it gets around this problem by paginating the KML file into multiple maps each supporting the maximum number of pushpins, lines or polygons. Unfortunately you can only embed one map page at a time, so the map above only shows the first set of polygons.

An interesting observation in the Microsoft blog post about KML support noted that, “on Google Maps the polygons representing the parks didn’t load at all”. Our KML rendered the polygons fine, but we took an extra step in GeoCommons to generate our polygons as multigeometries where a pushpin with the data is included inside the polygon and highlights when you mouse over (at least in Google Earth). So, my hunch is that in order to get polygon KML to render in Google MyMaps you need to structure it as a multigeometry, or they’ve added the functionality since then. It would be great to not to have to add the pushpin to get the data, and enable clickable polygons in both Google Earth and Google Maps.

On the plus side Google MyMaps does a good job handling multi-polygons. A multi-polygon is when you have multiple polygons representing one geographic entity. For instance the United States of America consists several separate polygons, including Alaska, the Hawaiian Islands, and the contiguous states. Several of the counties in our test data set had multi-polygons and you can see those rendered in detail in the embedded map below:


View Larger Map

A second plus for Google MyMaps is balloon support for the data that shows all the attributes in a nicely parsed list. Even when I loaded up a census data set with 74 attributes it listed them all out with a scroll bar. So to recap:

Advantages = prepopulated title and description, quick load, multi-polygon support, full listing of data attributes.

Disadvantages = limited number of polygons rendered on one map, requires multigeometry KML to support clickable polygons, slow rendering of polygons, no ability to export KML or other standard.

Virtual Earth KML Support

Virtual Earth KML support is provided through the “Collections” feature. When you click “Import Collection” you are given the option to add a KML file (or GeoRSS or GPX). I uploaded the same county pollution file and Virtual Earth chugged along for a bit then gave me a message saying, “100 out 100 items uploaded”. I’ve tried this with other files and if the files has more than 200 features it will not upload all of them - just the first 200 then stop. Also if your KML file is over 2mb it will tell you it is too large. Over all this is a nice feature that lets you know the bounds of the system and what will work and what will not.

The second nice part is that all 100 counties made it on one map instead of just 44 as with Google. A second bonus was that Virtual Earth did not need the multigeometries to support the clickable polygons rendered on the map. In fact the multigeometries we included in our KML generation caused both a pushpin to be drawn and and second square that gets highlighted when you mouse over the polygon. You can check out the map here and see the screen shot below:

MSVE_polygons

Sadly Virtual Earth does not support embeds, so just the screen shot and link. Another small ding, a,s you can see in the screen shot, is that Virtual Earth does not support multiple polygons. The spots where you see push pins instead of polygons is indicative of multiple polygons representing a county, like Galveston, that could not be rendered so a push pin was placed there instead. It still gets the job done, but there is still something dissatisfying about America’s or any other political unit’s borders being replaced by a push pin. The last complaint is Virtual Earth only supports a limited number of characters for attributes, so when I tested a census file with 74 attributes I only got the first twenty or so and they were not well formated. So to recap:

Advantages = ability to render more polygons, ability to render polygons faster, ability to support clickable polygons without mulitgeometries, ability to export KML (and other formats)

Disadvantages = inability to support multi-polygons, slow to load KML, limited support of data attributes, no support of balloon styling

Over all I would give a slight edge to Virtual Earth when it comes to KML support from our unique perspective. Specifically the ability to load a larger number of polygons on a map and make those easily clickable allows more of our content to be leveraged at this point. It will be interesting to see how Google, Microsoft and others continue to enhance KML support to make more data available. I believe there is still a long way to go and the vast majority of the datasets in GeoCommons are too large for either to handle at this point. As the GeoWeb and the data it interconnects becomes more sophisticated I think it will be a necessity to greatly increase the amount and complexity of data that can be handled in a browser based map. Hopefully the market pushes Microsoft, Google and others to innovate in that direction.

Popularity: 85% [?]

GeoCommons Metadata Implementation Screenshots

April 22nd, 2008by Sean Gorman

We got such useful feedback from the last metadata post I thought I would add some screen shots of how it is starting to come together. Unfortunately we were not able to get all the suggestions in because of the time crunch hitting our release date, but please keep posting the feedback and we’ll work it in as we have more time.

The first screen shot is of the data details page, which contains the metadata information for the data set. In this case 2000 US Census data at the tract level for Alabama:

finder_data_page

Here you can see the major elements we are capturing in a user friendly graphical lay out. One of the cool new bits is the system automatically calculates statistics when you upload the data. Being able to data mine and run statistics on the fly is one of the new developments we are particularly excited about.

All the metadata on the data details page is exposed as Dublin Core elements which should make them machine readable to the rest of the world:

finder_view_source

Also there are links to FGDC and ISO 19115 metadata mappings which take you to simple text pages with the indicated information. We probably need another pass to get these completely correct, but the infrastructure is all in place to do so.

FGDC looks like this:

Finder_FGDC

ISO 19115 looks like this:

Finder_ISO

Hopefully this will help make the data in GeoCommons useful to multiple geospatial work flows. We hope having the ability to get data out in shapefile, KML, and .CSV (spreadsheets) will create more cross fertilization between GeoWeb and GIS users. With some luck it can help get more geospatial data out to the public that has been difficult to access in the past. A couple of examples below.

US Census Tract Data for Alabama

Alabama Census Tract

Global Maritime Shipping Lanes

Global Shipping Lanes

Zillow Neighborhoods and Shipping Lanes (just because it looked kinda cool)

SF_neighborhoods

Thanks again for the feedback from folks on the metadata and we’ll keep iterating on getting it spot on.

Popularity: 38% [?]

FortiusOne Makes it as a Red Herring Finalist

April 17th, 2008by Sean Gorman

We got a bit of good news this week making the cut as a Red Herring Top 100 finalist. Considering there were over 800 companies in the running maybe this is not so bad. The folks in marketing are earning their ducats for sure. All the details can be found here.

In the bigger picture I think this is a good indicator of how the GeoWeb is becoming more mainstream and embraced by a larger business community. Hopefully this is one of many indicators pointing towards more business opportunities and investment dollars for the GeoWeb.

red_herring_finalist_logo

Popularity: 19% [?]