Saturday, October 27, 2007

Isla del Coco CS - Treasure Island

Isla del Coco

1) The first image is DigitalGlobe's (DG) coverage found in Google Earth (GE). Using GEs Path Tool, I digitized over 3/4 of the islands shoreline. The digitized shoreline from a DG image is considered to be EEVS precision, meaning scales below 1:12,500 is routinely possible. Once I had completed my GE phase of this project, I saved the completed EEVS shoreline with cloud-obscured gaps identified for later work. I was able to then load this KMZ file into Global Mapper (GM)

2) The balance of the shoreline was digitized using WRS imagery, specifically those identified as path 016 row 056. The imagery is packaged in 257MB TAR files. Once downloaded and unzipped, one can select from a number of TIFF images. I used nn40 tif image.

3) With the shoreline complete, I systematically added layers of information (name labels, land polygon, streams, contours). The SRTM image, N05 W088, served a double purpose. First, I was able to use GMs "Generate Contours" routine to create contours. In addition, The SRTM image was used to create a shaded relief image of Isla del Coco.


Isla del Coco - Island Image

Isla del Coco - Island Image Georectified JPG

Now for some data for all of you with mapping packages. I have zipped 9-layers of data that makes up the vector files for this project. The layers include: shoreline, streams, contours, name labels. Using GM, the zipped shapefiles load in about 2-seconds.

Isla del Coco - Vector Shapefiles

The second package contains a georectified JPG imag of the island and a DEM formatted file of the island. It should be loaded first with the JPG draped over it. You can do some neat 3D work with this combination of images.

Isla del Coco - Georectified JPG and DEM Files


Isla del Coco - 3D View SW to NE

Isla del Coco - 3D View SW to NE

If you load it with various vector layers, you can see them draped over the landscape of Isla del Coco.

Now for the "Treasure Island" stuff. According to Wikipedia, there are at least 3 treasures buried on this island. Pirates used the island as a hideout for years. Supposedly, Robert Louis Stevenson used Isla del Coco as inspiration for Long John Silver's Treasure Island.

Enjoy!

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