Thursday, February 28, 2008

Geography Game Using Google Earth

This is fun. And a productive time-waster. Where On Google Earth is a game using Google Earth. Those that run the site pick a spot on the globe and you are supposed to guess where it is.

From the game web site:

To participate, just make your guess in the comments section for each photo. Guesses will be held until the end of the contest, when they will all be made public. Anything and everything is fair game for getting a correct answer. Each contest will last 2-3 days, so submit your guess as soon as you have an idea.

Tuesday, February 26, 2008

Mapping Human Impact on Oceans

Today's Science Times in the New York Times had an interesting piece by Andrew Revkin on the impacts of humans on the oceans. As is so often the case these days with the Times, there were some great graphics (see above). I especially liked the newsprint version of the shipping lanes map since it is a subject I've studied and written about in the past.

Without mentioning GIS by name, Revkin discusses how these maps were generated:

A paper in the Feb. 15 issue of the journal Science is the first effort to map 17 kinds of human ocean impacts like organic pollution, including agricultural runoff and sewage; damage from bottom-scraping trawls; and intensive traditional fishing along coral reefs.

I tried to look up the Science article referred to by Revkin, but I don't have a subscription. It is called "A Global Map of Human Impact on Marine Ecosystems," by Halpern et al., 2/15/2008, p. 948-952, in case you're interested in sleuthing it out.

Another site referred to in the Times piece is the Census of Marine Life. The available map seems to be a work in progress but it is a place to watch for marine data and info.

Monday, February 25, 2008

Mac Tablet

Axiotron has a Mac tablet available with two pretty cool features: integrated GPS and DVD/CD combo drive.

Axiotron’s innovative design and manufacturing process integrates an Apple® MacBook® computer, state-of-the-art Wacom® pen-enabled digitizer technology and Axiotron's own proprietary hardware and software components into a complete tablet solution, the Axiotron Modbook.

I haven't tried Adobe® Photoshop® or Illustrator® on my TC1100 tablet. I wonder if those are pen-enabled. The Axiotron is clearly going for the graphic designer market here.

Sunday, February 24, 2008

Software for the Mobile Mapping Lab Tablets

As stated previously, we've decided on two types of tablet PCs for our mobile mapping lab - two Panasonic CF-19 Toughbooks and 15 HP 2710Ps. Now we are loading the software. Here's what we're putting on the new tablet PCs to get them ready for mobile mapping and teaching with GIS and other geopspatial technologies.

For functionality while back at the office (the Earth Science and Geography department), we bought a couple of HP ultra-slim expansion bases, a couple of USB-connected DVD/CD drives, and a couple of USB mouse/keyboard combos.

For mapping in the field, we bought extra Li-ion 6 cell batteries, some battery chargers, and an AC auto charger. Cases are still an issue, we don't have one yet for the HP tablets. We got the Panasonic Fieldmate Always On case.

Thursday, February 14, 2008

Excel, DBF files, and ArcGIS 9.2

I sent out an email to a GIS listserve asking for some help with a problem. Very quickly, I got back some great and helpful responses. All of that geospatial advice shouldn’t sit in my email archive, right? Here is a post that might help others who have the same question I had. To maintain anonymity, I signed their posts with their school affiliation just in case they didn’t expect their answers to be put out on the web.

Here’s was my question:
It seems that Microsoft Excel 2007 does not support the use of dbf files, either opening or "saving as". Is there a workaround that anyone knows of? On Microsoft's web site: "We have determined that a number of these older formats are seldom, if ever used. "...except for by GIS users!

Many thanks,
Vassar College

Here were the answers:

1) About working with Excel files in ArcGIS 9.2 - I found that by using Excel files in 9.2, it solved a lot of the problems that we would encounter with .csv, .txt, and .dbf files in earlier releases of ArcGIS. I wrote up a tip sheet to help my students out when working with Excel files, which some folks might find useful. I've certainly learned some new things following the discussion on this list. The Excel tip sheet is on the Tuft’s web page in the Working with Tables section.

Also go to ESRI’s page on using Microsoft Excel with ArcGIS 9.2.
From: Tufts University

2) If you have ArcGIS 9.2, it will accept excel files now. If not I would use a txt file.
From: California University of Pennsylvania

3) Fortunately, with Arc 9.2 we can use .xls directly (just make sure in Excel 2007 that you use that “compatibility” function that saves as an .xls 1997-2003 version), but when I had to revert to Arc 9.1 once last month (but still with Excel 2007) I saved as .txt and .csv and brought in to Arc without issues.
From: University of Redlands

4) It looks like that's only when Excel saves output; on input it will still read DBF files.

So with 9.2, the thing to do might be to join the Excel file (or a CSV file with 9.2 or 9.1) and then export the data as a new shapefile, which should produce the DBF for you.

Coincidentally I just stumbled across this trick in 9.2 (perhaps earlier, too): in ArcCatalog, right-click on a CSV file, and in its menu select "Export" and then "To dBase (single)...".

You can also open up an XLS file (in 9.2), point at a sheet or named region, and then do the same thing.
From: Amherst College

5) However if you use 2007 you need to save to the .xls 2003. But the 2007 does export to dbf too ... just hidden in their crazy menus.
From: Rio Hondo

6) And it seems the shape file must begin with a letter and not a number. We found that, for example, joining an Excel file to 1950_census.shp results in an SQL error. After renaming the file to census_1950.shp, everything behaves properly.
From: Wheaton College

7) I’ve heard that as well. I’m not using Excel 2007 yet, but the only workaround I can think of is to use ArcGIS to save your dbf as a text (CSV) file and then read it into Excel.
From: Middlebury College

8) Excel is still supposed to read dBase formats. A work-around, for the time it stops doing this, is to import the data into Excel through an ODBC connection or other database connection. It's possible you could also export changes to the data back out through the connection, but I haven't tried this.

There are subtle but serious problems using CSV files for data interchange, because they do not contain field type information. For example, string fields containing numeric strings (like zip codes, social security numbers, or US Census state/county/tract/block identifiers) will lose their leading zeros because Excel will assume these fields are of numeric type.
From: Haverford College

Meg here: I found that if I right click on the Excel file in ArcCatalogue (shown circled in red above), I will see the worksheets and then I can drag the table over to ArcMap.

Wednesday, February 06, 2008

Mapping History

I learn everything new about geospatial technologies from two sources. The first is Ogle Earth.

Stephen Geens blogged about the Time Space Map. It is billed as a geographic wiki. I think of the Google Earth Community BBS as that, so I think the Time Space Map is more elaborate. What a great concept and what potential this could have for academics.
Stephen writes: "Wouldn’t it be nice if all of Wikipedia’s historical events could be mapped to Time Space Map via some automated process? (That would avoid a lot of duplicated effort.) Wouldn’t it be nice if Google Earth’s timeline could be put to use exploring the history of any place you care to zoom in on, via a KML network link served by Time Space Map?"
I would take it further. Wouldn't it be great to share all places discussed in Wikipedia as KML files? Where is Poughkeepsie, NY? How about where is Poughkeepsie REALLY. James Baldwin grew up where? On the lower East Side? Battle of Normandy occured in the middle of France? You can zoom to locations in Wikipedia but it's not elegant at the moment and it is highly inaccurate. When you click on 'location' in Wikipedia, you should be able to launch Google Earth and fly there.

We have an ethnobotany professor working on a project in class this semester where the students will go out and map the locations of ethnic markets in the Poughkeepsie community. She wants the students to take photographs and upload them, with a description, to Panoramio and, of course, geolocate them, so that others can see these markets and what you can get there. Further, she wants the students to add content to the Wikipedia page for Poughkeepsie that will highlight the ethnic market community. If the two, Google Earth photos and Wikipedia entries, could be combined...that what be powerful. I'll post about this class later in the semester.

I mentioned two great geospatial sages. The other most-informed person I know about all stuff geospatial is Diana Sinton. She let me on to the fact (via a list) that the new book Placing History: How Maps, Spatial Data, and GIS are Changing Historical Scholarship edited by Anne Knowles (Middlebury College) and Amy Hillier (Univ of Pennsylvania) is out through ESRI press. Highly useful for those of us who support mapping, this book will be great to use for ideas for mapping in the humanities.

So, these two, seperate, unrelated topics are in the same post. Why? Because how cool it would be if Placing History could be designed to incorportate new tools like Time Space Map, right? That's the next book. Or I guess it would be an e-Book?