In Statetris, you rotate and position the state shapes so that they fall into the correct position, a la Tetris. Brings back not-so-fond memories of all the time I used to waste on computer games. Other useless geographic activities include Smoke Signals (animated smoke messages in Google Maps), and Crop Circle (personalized crop circles).
Archive for July, 2007 Page 2 of 5
USGS digital orthoquads are black-and-white aerial photos covering most of the continental United States, with a resolution of up to 1 meter per pixel. You can download orthoquad imagery from the USGS Seamless Server as well as other online archives, but the maximum extent of individual images from those sources is limited; if you need an image covering a large geographical area, you’ll need to assemble them piecewise from smaller images. Terraserver also provides digital orthoquad imagery, and there are some programs that will download Terraserver imagery for small geographic extents, but not large ones at the full resolution of one meter per pixel. If you don’t need the imagery to be georeferenced, or can georeference it yourself later on, TerraClient lets you download digital orthoquads covering extents of tens of miles on a side at up to one meter per pixel resolution in a single image file (the maximum area covered depending on your computer screen resolution).
After installing and running TerraClient (see addendum at bottom concerning downloads), you select the center of your area of interest by either entering the coordinates directly, or using a search box that lets you center on gazetteer features like cities, bodies of water, peaks, etc.. After selecting the center location, TerraClient will zoom to that location, and load in Terraserver imagery at an on-screen resolution of 64 meters per pixel (it says yards, but Terraserver data is in meters).
The slider controls in the left sidebar let you zoom in to up to one pixel per meter onscreen resolution, and also adjust the overall brightness of the image. Check the “Load Paper Map” box, and TerraClient will overlay a USGS topo map on top of the digital orthoquad, with the transparency of the map set by the bottom slider:
The controls at the top let you:
Pan - Move the image around by clicking and dragging
Zoom - Zoom in to an area by clicking and dragging on the map to select an area
Measure - Click on two points on the map, and find out the distance between them
Map Info - Click on the map, and get an info window that tells you when the aerial photo (mislabeled “satellite”) was taken, and when the topo map dates from:
Select - You can use this to select an area to download an entire image from, but you can also use Ctrl-A (or Edit => Select All) to choose the entire on-screen image.
To create an image covering the widest area possible, you would set the zoom level to 64 meters, and then use Ctrl-A to select the entire image. Then choose File => Save As to get the save options:
Use the zoom dropdown to select the image resolution, and TerraClient will give you the image size in pixels, and the total download size for the data used to create the final image. For the example above, the image size and filesize are fairly small; but if I set the zoom to 1, the image dimensions mushroom to 50129 x 41022 pixels, and the download size is a whopping 446 MB. You will have the option to save the image in JPG form (smaller filesize, but degraded resolution) or BMP (full resolution, filesize essentially the same as the download size). If the download size is too large for your system’s resources, you’ll get an error message to that effect, and you’ll have to reduce either the zoom level or the size of the selected area.
I don’t need a large, non-georeferenced orthoquad image that often, but when I do, TerraClient is a convenient way to get it. But it’s also an easy way to find the date when orthoquad aerial photos were taken, along with the date of the overlaid topo map data, and the blending of topo map images with aerial imagery can also be handy. It would be great if the program allowed you to save blended images, but it doesn’t.
Tomorrow, I’ll start a series of posts on another free Terraserver imagery program, one which in many ways is more useful than TerraClient.
Addendum: In comments, Raj points out that the download link on the TerraClient homepage doesn’t work, and offers a Softpedia download link that does work. You can also download it from the BetaNews FileForum.
OgleEarth posts about the King’s College Geodata portal, a terrific set of data overlays for Google Earth (static, network-updated, and temporal). Current datasets include:
- Tiputini Biodiversity Station
- Terrascope (new)
- TRMM 2b31-Based Rainfall Climatology
- Amazon-eye
- Tropical montane cloud forests
- MODIS Cloud climatology
- SRTM SWBD Coast and water bodies
- Petroleum-related impacts in the Amazon
- AsterPAA (TerraLook) in Google Earth
- GNS places database
- Monthly NASA blue marble SG
- Hole-filled SRTM 90m Digital Elevation Data
- Sea level rise scenarios
- Global forest change (2000-2005) from MODIS VCF
- Three-hourly rainfall time series (from TRMM 3B42)
- Monitoring Volcanoes
- Urban climates
- Tropical Hydrology : climate and land use impacts
- Central American and Costa Rican Climate and Hydrology
And, of course, there’s a lot more similar datasets at the Google Earth Library.
The last photo geotagging application I’ll cover for now is GPicSync, freeware from Francois Schnell. This application doesn’t have as fancy an interface as PhotoMapper, locr or Location Stamper, but it has some useful, and unique, features:
- It just works, cleanly and neatly. Set the locations for picture folder and the GPS file (GPX or NMEA), set the correct time offset between local time and UTC (aka GMT), and click the Synchronize button to geotag the photos.
- Pictures geotagged by GPicSync are recognized by Picasa right away; no need to re-process them with EXIFTool.
- You can create a Google Earth/Google Maps KML thumbnails file at the same time you’re geotagging the photos. You can also associate audio and video files with the pictures, so that GPicSync will create links in the Google Earth / Google Maps files that link to the audio/video.
- Handy tools include an EXIF reader, a utility that lets you manually embed geographic location into the EXIF header, a GPX file reader, and KMZ file generator to create a Google Earth file with the photo thumbnails embedded in it (unlike the KML file).
- And there’s a newsgroup where you can interact directly with the program author, report bugs, and suggest new features.
Thanks, Francois!
A few years ago, Microsoft was promoting something called the World Wide Media Exchange, WMMX for short, a centralized index of photos tagged by geographic location - sort of a proto-Flickr. It got a bit of press, but seems to have faded into obscurity. But it’s left behind a few useful utilities, including a nice, simple photo geotagging utility called Location Stamper.
You can download WMMX Location Stamper from this link. Note that while you need to have Microsoft .NET 1.1 or higher installed, you probably already have that on our system. You don’t need the WMMX Client Application at all unless you want it - it’s the program that lets you upload and browse photos in the WMMX index, and create photo slideshows, but isn’t required for the Location Stamper or any of the other utilities on this page. Install Location Stamper, then run it.
Not a lot of options, but it doesn’t need many. Add photos to be geotagged using the Photos => Add Photos menu, and they’ll show up as thumbnails on the right. Add your GPX track with the Tracks => Add Tracks menu, and the track will be loaded into the map window at left, along with an antique Microsoft MapPoint map for the area (it would be nice if they would update this with Virtual Earth, but I wouldn’t hold my breath). Click on the “Apply Tracks” button in the lower right, and the location/time data from the GPX track will be matched with the timestamp on the photo to geotag it. Select a photo that’s been geotagged, and a circle will appear on the track in the map window to show its location.
You can also geotag photos by zooming in to a location in the map window (click on the blue globe in the upper left to bring up a map if nothing is showing, or enter a location in the search box at the bottom), and then dragging a photo to a location on the map. But the map quality is so poor, it isn’t all that useful an option here - you’d be better off using Picasa with Google Earth for this kind of tagging.
Photos geotagged by Location Stamper appear to have fully-legitimate EXIF geographic tags, but as with locr, Picasa doesn’t seem to be able to recognize those tags. But EXIFTool, along with my utility, can modify the header so that Picasa does recognize the geotags.
As long as you’re checking out WMMX Location Stamper, you might take a look at some of the other utilities you can download from the WMMX page. The WMMX Travelogue Authoring Tool lets you create a geographic web page with your geotagged photos, maps, text and GPX tracks. If you download and install the full WMMX Client, you can create photo slideshows with maps and pop-ups that can be converted into files for viewing with the stand-alone WMMX Story Viewer.
If I need to convert a paper map to digital format, and the map is larger than my scanner, I usually scan the map piecewise, and then mosaic the pieces back together into a single image. If I’m lucky, I can get the Photomerge feature of Adobe Photoshop to put all the pieces back together into a single whole, and get good matching at the edges. More often, though, Photomerge can’t get all the pieces to fit together, and I have to match up the sections manually using control points, which is a real pain. But I’ve found a program that automates the process of finding control points and mosaicking map sections, and produces far better results than Photoshop’s Photomerge function. It can also mosaic images shot at different angles and rotations (like satellite/aerial photos) and overlay images to look for temporal changes. If the first image is georegistered, it can automatically georegister the product mosaic image as well.
More after the jump ….
AnyGeo and OgleEarth both post today on TakItWithMe, a new free web service that lets you upload Google Maps MyMaps KML data directly from your browser to a GPS unit. It’s limited now to Garmin units, since it relies on the Garmin Communicator plugin. And while the device support page indicates that some serial interface GPS receivers will work, Garmin says that it works best with USB devices, and doesn’t promise good serial support.
For other GPS manufacturers, and for KML files created in Google Earth or by some other means on your local computer, I’ve posted before about a number of free ways to upload KML file data into a GPS unit:
Exporting Data From Google Earth To A GPS Unit
Using GPS Utility To Import/Export GPS Data To/From Google Earth
GPS Trackmaker: A Better Solution For GPS Export/Import With Google Earth
There’s another way for Garmin units, but I’m waiting until it’s out of beta to post on it ….
Addendum: Google Earth Blog points out that TakItWithMe can also convert KML files to GPX format, so that you can upload them to a non-Garmin GPS using any program that accepts GPX, like EasyGPS or GPS Trackmaker.
In yesterday’s post, I talked about locr, a free program for geotagging photos both manually and with GPS data. One of its quirks is that while locr does successfully insert geodata into the EXIF header, Picasa is unable to read that data because the GPSVersionID tag written by locr isn’t properly recognized by Picasa. I don’t know whether that’s an locr problem or a Picasa problem, though I suspect the latter. There’s a command-line utility called EXIFTool that can re-write the GPSVersionID tag to one that Picasa will recognize, and I gave the command-line expression to use in yesterday’s post:
exiftool -GPSVersionID=0.0.2.2 -overwrite_original *.jpg
But I’m not a big fan of command-line utilities, so I’ve whipped up a quick GUI that will do the same thing called EXIFTool GPSVersionID Fixer. Download and unzip this GUI program into the same directory that has the utility exiftool.exe (renamed from exiftool(-k).exe, the name it has in the zip archive), then run it:
Select the folder that contains the JPG files geotagged by locr (or any other geotagging problem that’s giving Picasa problems), then click on the Execute button and you’re done. If the folder contains both tagged and untagged photos, that won’t cause any problems. Not a lot of error-checking, but it will flag you if you haven’t selected a directory.
Unfortunately, it doesn’t fix this problem for photos geotagged by PhotoMapper. But it’s worth a try for files geotagged by any other program that Picasa (and possibly other programs) might be having a problem recognizing.
Addendum: Mike Lee points out that you don’t need to have EXIFtool in the same directory as EXIFTool GPSVersionID Fixer; you can also put it into any directory specified in the Path command loaded when Windows starts up. That typically includes the Windows directory (e.g. c:\Windows) and the Windows\system32 directory. Thanks, Mike!
Other free utilities can be found on the Utilities page. If you find this or any of my other utilities particularly useful and would like to show your appreciation, donations of any amount are gratefully accepted via PayPal.
