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Archive for July, 2008

A Simple Online KML Polygon Creator – With Holes!

Kjell Scharning emailed to let me know of his simple Google Maps tool, a basic digitizer with a Google Maps interface for creating KML polyline and polygon files. While for most purposes, the Google Maps MyMaps creation tool is a better choice, Kjell’s tool does have some useful functions missing from the Google Maps editor:

  • Creating circular shapes
  • Creating polygons with holes in them (something you can’t do directly in Google Earth, either)
  • Get a list of vertex coordinates as created (select the “KML Coordinates option”). There’s also a separate KML “editor” that will take a link to a KML file, and give you a text list of the vertex coordinates. You can move the vertices around in the “editor”, but it doesn’t actually edit the KML, just modify the coordinates in the list.

As you click on the Google Maps interface to create vertices for the polyline or polygon, the KML text will be updated in real-time in a text window to the right of the map:

Google Earth shape with hole

The instructions are a little unclear on hole creation. To create a shape with a hole:

  • Choose the “Polygon” Draw mode
  • Set the style for the shape (color, fill, perimeter) with the “Style options” button, then draw the shape in the map. Be sure to end the shape by clicking the “Close Polyshape” button.
  • Check the “Hole” box; the perimeter of the main shape will turn into a polyline, and the draw mode will switch to “Polyline”.
  • Draw the shape of the hole on the map, using the “Close Polyshape” button to finish the hole.
  • Click the “Polygon” Draw mode option, and you’ll see your original shape with the hole inside of it.

Once you’re done, click the “Select and copy text” button, then paste the code into a text editor and save it as KML file.

It currently only seems to work in Internet Explorer and Firefox 2, but not in Firefox 3. And you can only draw one shape at a time. Not a complete editor by any means, but you may find its unique features handy.




Uploading .img Map Files To A Garmin GPS Unit With MapUpload

A while back, I posted about MapSet Toolkit, a program that adds information about Garmin-map-format .img files to MapSource, so you can upload them with that program to a compatible Garmin GPS unit. But there are several faster and more direct ways to upload a .img file to a Garmin unit which don’t require installation in MapSource; they may be more convenient for a single map file, or for evaluating a map file before installing it as a MapSource option.

The first one I’ll cover is MapUpload, from the creators of MapWel, a program for creating custom maps for Garmin GPS units. MapWel isn’t free, but MapUpload is; there’s a list of supported Garmin units on this page.  Just download and run (no program installation):

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If your GPS unit is turned on, it should be recognized automatically, and info displayed in the Status window. If it’s off, turn it on and select “Detect GPS” from the GPS menu. Select .img files by clicking on the list at left (or the menu Files => Add img files to the list), and using the file selection dialog; there’s room for up to 300 files on the list. Click on “Upload to GPS”, and the maps will be sent to your GPS. There’s no way to tag a set of maps with a label; on your GPS, they’ll all have the category label “Custom area created with Mapwel”, followed by the .img creation date.

The default is to delete the current mapset, but if you check the box “Add to existing maps”, the maps on the list will supposedly be added to the maps currently loaded onto the GPS. I’ve had mixed success with this option – it seems to work better with small installed mapsets than with large ones. And if you have a large set of maps on your GPS, it will take a while to merge them, since the connection is either serial (unbearably slow) or USB 1.1. (painfully slow), and MapUpload first has to download the full mapset, then merge it with the new maps, then upload it back again. It doesn’t support the faster option of uploading data onto a memory card in a higher-speed (USB 2.0) card reader. There’s also no way to save a map list, so you have to select individual map files every time you want to do an upload. On the plus side, you can create a stand-alone program that takes all the .img files, and puts them into an executable that will upload the data to any attached, compatible Garmin GPS unit.

On the plus side, MAPUpload is fast and simple. If I have one or two maps I need to upload quickly, especially if I want to merge them with the current mapset, it’s my program of choice. For larger sets of maps, you’re better off using MapSet Toolkit, or other options I’ll cover soon.




A Cheap Video Whiteboard/Motion Tracker/Touchscreen System For PCs

Check out this 5-minute TED presentation by Johnny Lee on using a Wii Remote with a Bluetooth-enabled PC, simple IR LED, and video projector to create a simple video whiteboard, hand/motion tracker or touchscreen system:

Seems like a good match for digital globes like Google Earth and WorldWind, or for some GIS display systems. There’s more information, including software and source code downloads, at Johnny Lee’s website, and more information is also available at the WiimoteProject forums.




Create Bicycle/Travel Courses For Your Garmin Edge/Forerunner GPS With Bike Route Toaster

Although it’s primarily aimed at bicycling Garmin Edge/Forerunner owners, Bike Route Toaster is a useful tool for any GPS user, or anyone planning a bike road trip. Create a course in a Google Maps interface by adding points along the route; Bike Route Toaster gives you the option of auto-routing, where it connects the points along roads and adds directions:

Continue reading ‘Create Bicycle/Travel Courses For Your Garmin Edge/Forerunner GPS With Bike Route Toaster’




Plot Google Analytics Geographic Data In Google Earth/Maps

Johann Blake writes about his new tool to plot geographic Google Analytics data in Google Earth or Google Maps. Just follow the instructions on the website to export the Analytics data in XML format to your computer, then upload the file to the site. You have the choice of creating either a straight KML file for Google Earth, or a direct plot of the data in Google Maps; the latter doesn’t seem to work currently in Firefox 3, but does work in Internet Explorer. You get placemarks for every country from which you had a visitor, color/type coded by the total number of visitors:

gega

Click on a placemark in either Google Earth or Google Maps to see the number of visitors from that country. You can use the standard Google Analytics controls to select the desired time frame, and also filter data.

It appears as though you can also select geographic sub-regions in Google Analytics like the US states below. I did get a bunch of error messages in Google Maps, and the District Of Columbia plotted in the South Atlantic, before the rest of the states plotted correctly:

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This older tool was able to plot individual visitors, but required a raw data export capability that Google Analytics no longer provides. So for now, Johann’s site is the best available GE/GM Analytics tool.




US Nautical Chart Overlay For Google Earth

Navimatics has created a KML network link that overlays marine charts derived from NOAA data onto Google Earth. Coverage includes all of the US coastline for the contiguous 48 states, but not Alaska and Hawaii yet. From high altitudes, coverage areas are outline with yellow lines:

Continue reading ‘US Nautical Chart Overlay For Google Earth’




SPOT Medium-Resolution Multispectral Imagery For Canada

Slashgeo links to an announcement on Canada’s GeoBase site that SPOT imagery will become available for all of Canada by 2010. Panchromatic (black-and-white) imagery will be at 10-meter resolution, while four multispectral bands (Green, Red, Near IR, short-wavelength IR) will be available at 20-meter resolution; this is compared to Landsat 7 data (also available from GeoBase), with 15/30/60-meter resolution but more bands (one panchromatic, 6 multispectral, 2 thermal IR). A fair amount of imagery is already available:

canadaspot

Free registration required for access to GeoBase’s downloadable data, which includes a lot more Canadian geographical datasets (road networks, hydrography, topography, and more).




The Simplest Windows Photo GeoTagging Tool

The website for GEOTaggingTool is in Russian, there’s no English documentation there, and there’s no help file included with the program. But as long as you can find the download link at upper left for version 0.5.1, that’s all you need. The program itself is in English, and there’s no install program; just unzip it into a folder. This has to be the simplest Windows photo geotagging application out there; click one button to open the GPX track, click another to open the images folder, then click “Process GEOTagging!” and the images will be geotagged (but be warned, the old images will be overwritten with the new geotagged versions without notice).

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The only available options are setting the time offset and window for matching GPS track times with photo times, but GEOTaggingTool handled the time offset between my local camera time and UTC GPS time without touching these. Fast, simple and easy.

Note: Requires Microsoft .Net 2.0.