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Archive for the 'Google Maps' Category Page 2 of 15



Create Your Own Google “Map Envelope”

The Map Envelope site lets you select a location, then generates a printable envelope with a Google Maps image of the map location printed inside. Select a location and message in the main interface:

mapenvelope

When you’re happy with the view, hit the Preview button to see how the template will look like before you print it:

mapenvo

Then hit “Print Envelope”, cut out the map, fold along the dotted lines, and tape/glue it together to finish the envelope.

Tips:

  • Print Envelope button may not always be responsive – may take several pushes for it to register.
  • Printing worked fine in both Chrome and Internet Explorer, so you can probably ignore the “Get Firefox” message.
  • You can’t scroll the map image around to position it exactly, so you’ll need to be as specific as possible for the location. Addresses work well, as do latitude/longitude coordinates (get these from Google Earth, or using the Google Maps Labs LatLng Marker). Enter the name of a city or town, though, and it will give you a fairly arbitrary location in that place.
  • Final envelope is fairly small in size (~4-7/8” x 3-3/8”; 12.5 cm x 9 cm)
  • You’ll probably get the best results (and the most rugged envelope) using photo matte paper.



Displaying GPS Data On A Website

Got an email a few weeks ago from someone who wanted to post data taken with a GPS, in GPX file format, and display it as an embeddable map on his blog; he couldn’t find anything on that on the web. I offered one possibility, and he in turn suggested that I might put up a brief post on the topic. Here’s a few ways to do it, off the top of my head.

Some of these will require you to convert your GPX data into an alternate format, like KML or shapefile. A search of this website will bring up lots of programs that can do these conversions, but probably the simplest way is to load your GPX file into Google Earth, then export the data in KML or KMZ format. Note: All of these sites require you to create a free account.

Google Maps My Maps – The alternative I suggested; not a lot of features, but very easy to use. Import KML/KMZ files from your computer or a web link, use the built-in editor to add additional features. You can then display the map on your website using a widget.

Google Docs Spreadsheet – If you convert your GPX files to CSV files using a program like DNRGarmin or GPXToPOI, you can import the data into a Google Docs spreadsheet; Google offers a tutorial on converting that data into a KML network link for display in Google Maps or the Google Earth plugin.

GeoCommons – Just posted about this yesterday; upload your data and display it in widget format. All data you upload will be available for anyone to use or download.

MapChannels – Lots of map creation features, and embeddable maps.

ScribbleMaps Pro – Similar to Google Maps My Maps, but offers lots more import options and drawing tools. Highly recommended.

Feel free to add your own recommendations in the comments section.




Compare Point Latitudes And Longitudes With Iso-Longitude-Latitude

For some reason, I have this mental picture of Europe being at about the same latitude range as the US, and I’m often startled when reminded that much of Europe lies well north of the lower 48’s northern border. The Iso-Longitude-Latitude site shows this graphically; put a marker on a point in a Google Maps interface, say near New York City:

nyc

And lines of constant latitude and longitude will be drawn through that point in the first map window, and in a second one directly below it. By scrolling the map eastward, I can see that Madrid is at about the the same latitude as NYC:

madrid

And that most of South America is east of NYC:

sa

You have the option of showing the “anti-latitude” and “anti-longitude” of a point as well; anti-latitude is the equivalent south latitude of a northern latitude (and vice-versa) e.g. +40 and -40, while anti-longitude is180 degrees opposite longitude, e.g. –75 and +115. “Anti” lines are drawn in red.

You can enter multiple point positions on a map, and their coordinates will show up in a text box; alternately, you can copy and paste coordinates into the text box and display them on the map. Finally, you can save a URL that will save and display all the points you’ve entered.




Distances And Calories Burned With The Gmaps Pedometer

Another route-drawing app for Google Maps, but with some unusual features. The Gmaps Pedometer lets you create a route by clicking in a Google Maps interface, as do many other similar apps. Some of its features are:

  • The route can be straight lines between points, or be automatically routed for either running-friendly or cycling-friendly routes
  • Optional mile markers can be drawn along the route
  • Total route distance is calculated on the fly
  • You can display a graph of elevation change over the route
  • You can automatically do an out-and-back calculation for a return trip by the same route
  • Enter your weight and get an estimate of how many calories you’ll burn
  • Save the route as a permanent link
  • Print the map
  • Export the route to GPX (this is an external link to the GMapToGPX site)

Map/route and elevation display:

mapandelevationdisplay

Control panel and info readout:

cp

Tips:

  • Set all parameters (units, calorie counting, mile markers, etc.) before you start adding points; there doesn’t seem to be a way to change those after you’ve created the route and have those changes reflected in the map/display
  • Press the “Start Recording” button to start entering points, and double-click on the map to enter a point
  • If you want to export the route as a GPX, you should visit the GmapToGPX site first, and configure your browser as indicated to allow GPX export.
  • I modified the Gmaps Pedometer link slightly so that it would start out centered on the US; to customize it for your own center point, take the link URL (http://www.gmap-pedometer.com/?centerX=-90&centerY=35&zl=13&fl=m) and substitute your desired longitude for the centerX value, and latitude for the centerY.



Compare Geographic Boundaries With Move Outlines

I can remember as a kid (way too many years ago) being impressed with a map of the lower 48 United States that had the outline of Alaska superimposed on top of it. The Alaska outline virtually covered the entire map, and there was a comment to the effect that,”Alaska is almost as large as the lower 48 states”. It wasn’t until years later that I realized the creator of that map had just traced an outline of Alaska off of a Mercator projection map and laid it on top of the US map without compensating for the change in scale.

If only the map maker had had access to  Mapfrappe’s Move Outlines site, he might not have made that mistake. Draw an outline of a geographic area in one Google Maps window:

tracedoutline

And have the outline be superimposed on top of another Google Maps window, scaled correctly to compensate for changes in the Mercator scale at different latitudes:

superimposed

Alaska’s still pretty dang big, but this shows it at its true scale, roughly one-third the size of the lower 48.

Another classic example of this is Greenland, which looks humungous on a standard Mercator projection:

greenlandoutline

In true area, though, it’s roughly the same size as Mexico; big, but not gargantuan:

greenmex

The site has some pre-drawn comparisons, like the Great Lakes against the Black Sea:

greatlakesvsblacksea




Draw A Polygon In Google Maps, Get The Enclosed Area

With the Google Planimeter site, click on the map to add polygon points:

nmpoints

And have the area enclosed by the points be calculated in multiple units:

areas




Find Your Own Double Rainbow – So Intense

One of the more interesting Google Maps mashups I’ve seen in a while, OMGRainbows! mixes information about where it’s raining in the United States along with the angle of the sun, and plots areas where you’re most likely to spot rainbows. To see a rainbow, you need to have the sun behind you, shining towards an area where there’s rain falling. If the sun angle is too high, you’ll a solid yellow overlay:

norainbows

But if the sun angle is acceptable, you’ll get a plot in red that shows the areas where you could see a rainbow if the sun is visible:

rainbowzones

And when night falls, you’ll get a dark overlay showing where there’s no sun to generate a rainbow:

rainbownight

And if you don’t understand the post’s “intense” title:

Via GoogleMapsMania.




Crowdsourcing And Coordinating Data Collection With Handheld GPS Units

Got an email today from someone with a data collection/coordination/assembly problem. They have multiple people out in the field with Garmin GPS units recording data, and bringing it back to a central location for collation/combination when they’re done. Since Garmin GPS units have limited capabilities for data storage – coordinates, name, comment, date and time, elevation, and that’s pretty much it – additional data associated with a point has to be recorded by hand. Once back from the field, data has to be downloaded from individual units, associated with the additional attribute data from forms, all the data combined together into a single dataset, then converted into GIS-friendly format. And the process they had come up with wasn’t really working well for them.

I think this highlights some of the major limitations of classic stand-alone handheld GPS units. They’re really designed for us in personal data collection, not combined data collection; assembling data from multiple units can take a lot of work. Plus, their limited data collection capabilities require offloading data attribute acquisition to other formats (e.g. pencil and paper), adding the addition problem of associating that data with coordinates later on. There are lots of professional solutions for these problems, like Trimble or MobileMapper GPS units, Terrasync and ArcPad software, but these can be complicated and expensive. I challenge you to find anyone with enough patience to use Terrasync for a single day without swearing at least once; I know I can’t  ;-).

For a few years, I’ve had CyberTracker on my list of potential topics to post on. CyberTracker is a terrific data acquisition and collation tool for field data with tons of great features, like custom data acquisition form design for easy data entry, moving maps, easy data collation and conversion to GIS-friendly format. Plus, the software is free, and the hardware is (relatively) affordable. But unfortunately, I think time and technology are passing Cybertracker by:

  • While the central data software runs on Windows, the field data collection software runs on old-school Palm OS and Windows Mobile. Palm OS is dead; Windows Mobile development has stopped with version 6.5, and only maintenance updates are scheduled. So the useful lifetime of any data collection system built around CyberTracker is limited. If you need a fast/cheap/short-term solution, CyberTracker is free for non-profit use, and you could probably pick up the hardware very cheaply on eBay. Long-term, I don’t see it having much of a future in its current form.
  • The data collation model is also becoming obsolete. With CyberTracker, you have to bring all the data units to a single data download/collation computer. While there are still places in the world where this might make sense, an increasingly-connected world means that data download/collation to the cloud instead of an individual computer makes more sense.

I’m really excited about the possibilities for crowdsourced geographic data collection and collation using portable devices running Android OS (yeah, iOS too). There are already several interesting apps for doing this, and I hope to cover some of those soon on my AndroGeoid website. And I suspect that the small number of apps that can currently do this will be quickly joined by far more apps, and far more capable apps, in the very near future. But that doesn’t help with my emailer’s current problem. I suspect there are many different ways you could do this, but here’s the first approach that came to me using all-free software and services.

1. Make sure that everyone on the project has a Google account (i.e. Gmail); completely free.

2. Have the project leader created a single main data spreadsheet on Google Docs, with all the desired data attributes (e.g. point name, coordinates, comments, additional data fields from the paper forms, etc.) and share a link to that spreadsheet with other project members so that they can edit it as well.

3. Project members can download data from their Garmin units using DNRGarmin, and then export the data from DNRGarmin in CSV format.

4. Load the data into the spreadsheet program of your choice, and add/edit data from data forms to make it conform to the data structure of the main Google Docs spreadsheet.

5. Copy the data cells in the spreadsheet program, and paste them into the main Google Docs spreadsheet. Note: Use Ctrl-C and Ctrl-V to copy and paste cells into Google Docs instead of using the Google Docs Edit menu to perform those operations, as the latter doesn’t seem to work for pasting data from different applications into Google Docs. You no longer have a single computer as a choke point for data entry; multiple people can add data to a spreadsheet at the same time, and Google Docs will coordinate data entry so that nothing is lost. And if you save the spreadsheet data from steps 3 and 4 as separate files, you’ll have backup copies of the original data as well.

For those who aren’t comfortable with working with spreadsheets, Google Docs lets you set up a “Form” to let anyone add data to a Google Docs spreadsheet directly; however, this increases the chances of coordinate data entry error.

6. Now that you have all the data centralized in Google Docs, you have lots of flexibility in how you can handle it:

  • Export the data in CSV format, and you can then import it into any GIS program that supports CSV data. If your GIS program doesn’t, use MapWindow to convert your CSV file into shapefile format first.
  • Unlike shapefile attribute tables, where adding/removing/re-ordering attribute data columns can be a pain, you can easily perform those operations in Google Docs and then re-export the data in CSV format.
  • Convert the data directly into a continuously-updated KML network link for display in Google Earth or Maps using Google’s Spreadsheet Mapper tool.
  • Use any of Google Docs built-in tools to analyze/plot/sort/visualize data, including their way-cool Fusion Tables.
  • And I’m sure there are more options I haven’t thought of.

Know an alternate approach? Have any additional ideas?  I welcome your links and suggestions in the Comments section below.