Thoughts - North Sentinel Island Five Years After the "Big" One

North Sentinel Island - Pre December 26, 2004

North Sentinel Island is home to a few hundred of the most isolated people on the earth. This group of people has chosen to remain separate from all other peoples. To the credit of India, they have been allowed to remain separate. Prior to December 26, 2004, the inhabitants were content to hunt and gather on their small forest covered island. Then came the dreadful 9.0 earthquake that caused death and destruction throughout this part of the world. North Sentinel Island was not spared. It is unclear if any of the inhabitants were killed as a result of the earthquake. What is clear is that the island underwent a dramatic transformation. This small island was thrust upward. The submerged reef was no longer submerged.

North Sentinel Island - February 2005

The February 2005 image shows the once submerged reef exposed above water. The forest is intact, but the island's fringing reef is now permanently above water. The stark white indicates that the reef is a new comer to the above-water environment.

North Sentinel Island - November 20, 2009

Fast forward to last month and one sees the reef still above water, but undergoing a gradual color change. As the once bone white reef remains in contact with the outside air, dust particles are blown onto the reef daily, algae colonies live and die and organic debris flows out from the island proper onto the reef, all of this contributing to the raised reef's gradual discoloration.

North Sentinel Island - EEVS Precision Map (1:62,500)

My post-earthquake map still gives a good picture of this small uplifted island. I'm glad it remains isolated and it's inhabitants have yet to encounter the world of modern man.

Enjoy!

Thoughts - They Aren't as Good as EVS Precision and That's the Fact , Jack!

Olimarao Atoll Locator Map

You all remember my last post, Olimarao Atoll? I spent a few days prior to posting it doing research into available online mapping. I checked out the standard mapping packages for Olimarao Atoll vicinity maps. Check out my results below...

Olimarao Atoll - Vicinity Map from Google Maps - Some land polygons, no labels.

Olimarao Atoll - Vicinity Map from Yahoo Local Maps - Nothing here.

Olimarao Atoll - Vicinity Map from Bing Maps - And nothing here.

Olimarao Atoll - Vicinity Map from OpenStreetMap - Land polygons and labels.

Google, Yahoo and Bing Maps rely on satellite imagery. The underlying maps of these oceanic island areas are largely neglected in map coverage. Google Maps provides land polygons from a mapping file similar to WVS 1:250,000. OpenStreetMap uses NGA PGS polygons along with NGA Country name files. Clearly the superior map product for oceanic islands is found on OpenStreetMap. But wait! What about a vicinity map using what I call EVS rough precision digitizing. Using Landsat ETM+ imagery, I could quickly digitize island polygons and reefs giving a much clearer map of the island.

Elato, Lomolior and Olimarao Atolls - Landsat N55-05_2000 Coverage

Landsat N55-05_2000 is the imagery I initially tried to work with. As you can see, The vicinity is not covered. It is a blank. So I did what any good mapper would do, improvised. Using Google Earth, I found the blank area and DigitalGlobe had hi-res imagery of the islands located within the blank area.

Elato and Lomolior Atolls - DG Preview Image from GE

Elato and Lomolior Atolls - DG Preview Image from GE Cropped

I decided to use the DG Image Preview from GE. I copied it, cropped it and georectified it. From there, I was able to complete the digitizing within a few minutes. I did this for all islands within the Landsat blank area. Atolls should have reefs digitized as they make up a critically important aspect of this feature. My finished map uses five layers - 1) land polygon 2) reef shallow 3) reef deep 4) ocean and 5) name labels. My island name layer is an extract from NGA's country files.

Olimarao Atoll - Vicinity Map from EVS Rough Precision (1-500,000)

This was all done using Global Mapper. The scale for the above map is 1:500,000. Now that is what I call a real oceanic island vicinity map.

Enjoy!

Olimarao Atoll FM - A Northern Pacific Island Jewel and Uninhabited Too

Olimarao Atoll - DG Island Image from GE (=~1:25,000)

Olimarao Atoll - EEVS Precision Map (1:25,000)

After almost five years of EVS precision island mapping projects, countless comments from the curious and, most often, complimentary guests and thousands of hours of work aimed at making this website better...

1) I have struck a deal with a corporate "sugar daddy" that will pay me to make EVS and EEVS precision island maps as I see fit.

or

2) My wife finally put her foot down and instructed me to "shut it down"! I told her to back off and she left me for a younger, computer illiterate man.

or

3) I'm still making island maps, with my wife's blessing, and am still without a corporate "sugar daddy".

Okay, I'm at Option 3) and enjoying it. However, sometimes our complicated lives cause us to wish for profound simplicity. A place where one can get away from the pressures of "big city" living and spend a day making a single decision, that being to make no decisions.

By far, my most popular posts over the past few months have been about the challenge of locating and living on uninhabited islands. It started with my post "Thoughts - An Uninhabited Island and What You'll Need to Inhabit it 'Robinson Crusoe' Style" and continued with my post "Thoughts - How Many Uninhabited Islands in the World?". These two posts alone have generated over 1,000 page views. As the world's economies continue to struggle and the economically downtrodden victims hunt for ways out, a Google search of "uninhabited islands" will lead the desperate to my aforementioned posts.

Olimarao Atoll could be their Eden. The atoll is small, but affords one fairly secure anchorage near the large motu. The large amount of vegetation suggests an adequate supply of water, most probably in the form of a fresh water lens. The small size of the island might lead one to "island claustrophobia", manifest by a longing for continental security. However, according to the occasional yachtsperson stopping for a short stay, the island is beautiful beyond imagination. Could Olimarao Atoll be your Eden? More to follow...

Enjoy!

Thoughts - Strange Maps: An Atlas of Cartographic Curiosities

Strange Maps: An Atlas of Cartographic Curiosities

When I first exchanged emails with Frank Jacobs, it was shortly after my "Titan's Unnamed Methane Sea" had hit the internet. The subject of the map hit a hot button that translated into 1,000s of visits to this web site. Frank introduced himself and asked if I had visited his blog, Strange Maps. I had and shared that I thought it was a "kick". He revealed that he, likewise, was a follower of my mapping efforts. He most especially liked my Titan map and wondered if he might use it in a book he was going to have published. He quickly added, that he had no money to pay for the use of the map, but would make sure I got a copy of his completed book. "Of course!" I said, "You are welcome to use my map. Just give me proper credit." Deal done!

Now let me tell you what I really thought. Oh, sure. This guy is going to publish a book about strange maps. I'll probably get a pdf copy or a link to his self-published effort. Unfortunately, I do have a healthy streak of skepticisim. After our exchanges I forgot about Frank and his book.

Silly me! I will never doubt Frank Jacobs again. True to his word, last week Fedex delivered a package from the UK. Inside was a slick copy of Strange Maps, Frank's book. I quickly leafed through it and there was my Titan map on pages 206-207. A nice writeup is included speculating on a name for this methane sea. And, sure enough, a paragraph about the author of the map, me.

Buy the book! Amazon.com lists it at $19.80. Support a fellow map lover!

Titan's Unnamed Methane Sea with Lat-Lon Grid (1-750,000)

And, once again, this is my map of Titan's Unnamed Methane Sea. It is still an interesting effort and now my first published map.

Enjoy!

Motu Iti FP - Smaller is Quicker

View Motu Iti FP in a larger map

Motu Iti FP - DigitalGlobe Image from Google Earth (1:10,000)

Motu Iti FP - EEVS Precision Map (1:10,000)

According to widely accepted geographical feature identification practices Motu Iti and the rocky islets to the east are classified as islets (> 1 sq km). They are still defined as islands for the purposes of claiming Exclusive Economic Zones (EEZs), sea level to seafloor ownership encompassing a radius of 200 nm or 370 km from this island's shoreline. Interesting as this might be, it is not the reason I mapped these islets. Yesterday, I needed a break from the Komodo Islands project and these islets looked like a good option. I like the Marquesas and these are a part of the Marquesas.

There was nothing especially challenging in the shoreline mapping of these islets. The DigitalGlobe imagery is exceptional. I did preliminary shoreline mapping in Google Earth and finished the project up using Global Mapper. I've spent about 4-hours from start to finish which is par for the course when mapping a simple island shoreline.

Now for my guess work. The main islet, Motu Iti, has scatter vegetation on it. My source, Vegetation of the Tropical Pacific Islands found in Google Books, states that three types of low lying vegetation are found on the islet (Perlman, unpublish notes, 1989). The main islet is said to be 220 meters high. Based on this unsubstantiated elevation, I guesstimated 25-meter contour intervals using visual interpretation of the base imagery. I was unable to use SRTM coverage for these islets as it is of very poor quality. It would be nice to have side views of these islets, but alas, no side views were turned up in my research. Consequently, the elevations are educated WAGs (Wild A...d Guesses).

I'll rest up today and spend time with my wife, doing long overdue honeydos. She will be happy and so will I.

Enjoy!

Thoughts - Working on the Komodo Islands EEVS Precision Island Mapping Project

Komodo Islands, Indonesia

Bima, Indonesia (txu-oclc-21752461-sc50-4) Perry-Castañeda Library
Map Collection

Why Make Another Map of a Previously Mapped Island?

The highly detailed mapping for this group of islands is paper. I create digital maps. The paper map lives in a library map drawer. My digital map will be available for any person wishing to use it. The raster imaged map above is a US 1:250,000 scale topo created from aerial surveys conducted in the 1940s and 50s. The scale my finished map will be useful is between 1:50,000 to 1:125,000. My map will contain additional layers of information detailing types of vegetation and reefs. Plus, I just like to make island maps.

Komodo Islands - EEVS Precision Digitizing using Landsat ETM+ Imagery (1:20,000)

Komodo Islands - EEVS Precision Digitizing using ASTER Imagery (1:20,000) Credit: NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team

Komodo Islands - EEVS Precision Digitizing, Size Modified (1:20,000)

Better is Better and More Accurate is More Accurate

I love the ASTER imagery for this island group. It is extremely detailed and provides a cloud-free look at almost all of the islands within this group. One is able to get an excellent view of different types of vegetation - mangroves, dense forests and scattered brush. Comparing it to the Landsat ETM+ image, the ASTER image provides a greater amount of cloud-free coverage. Combining the two images, ASTER and Landsat, one is able to create a virtually cloud-free image of the Komodo Island group. In the tropics, cloud-free is unique. One challenge was the georectifying of the ASTER image to the Landsat ETM+ image. It took 27 unique ground control points to twist, stretch and tug the ASTER image so that it precisely overlay the base Landsat image. Once that task was accomplished, I got around to digitizing layers of information. My first layer is always the island shoreline. Then comes all of the additional layers. I have completed the beaches and an inland vegetation layer at the northern end of Pulau Komodo and am currently working on the mangrove forest layer.

Pulau Siaba Besar and Kecil Islands - Landsat ETM+ Image (1:20,000)

Pulau Siaba Besar and Kecil Islands - ASTER Image (1:20,000

Pulau Siaba Besar and Kecil Islands - EEVS Precision Map, Preliminary (1:20,000)

Mapping at EEVS using ASTER Imagery

The above map is an example of the level of detail one can extract from the ASTER image. Those dark green areas along the island's shore are mangrove forests. Interestingly, these mangrove forests seem to primarily form along the eastern shores of the islands. This would be where the water is less turbulent.

Komodo Islands - Mangroves

The vegetation layer identified as EVS Vegetation Wetland, mangrove forest, detailed on the Pulau Siaba Besar map above, would look like the above image, dense dark green foliage along the shore. The dense dark green foliage that one sees inland will be classified as EVS Vegetation Forest (Hi). As you can see from the above image, much of the land is sparsely covered with vegetation. I have identified that layer as EVS Vegetation Scattered, which will include low lying grasses and small bushes.

Comparison - Landsat ETM+ to ASTER Images (1:5,000)

Pulau Siaba Kecil Island - DigitalGlobe Image from Google Earth, Size Modified (1:5,000)

Pulau Siaba Kecil Island - EEVS Precision Map, Preliminary, Size Modified (1-5,000)

Mapping at Scales Between 1:1,000 to 1:2,500 Using DigitalGlobe Imagery

In a perfect world, maps created from DigitalGlobe imagery found in Google Earth would be owned by their map maker and that map maker would be free to use that map anywhere and anytime they wished. No restrictions. No ownership delimmas. Just a map one would be free to use as one sees fit. But this world isn't perfect and DigitalGlobe and Google Earth have stern restrictions on how one is allowed to use their imagery. Pulau Siaba Kecil EEVS precision map was constructed off of DigitalGlobe imagery found in Google Earth. I am able to post my map, but there are restrictions on how I might use this map further. With that said, let's move on.

I decided to experiement using DGs hi-res imagery found in GE. I have used their mapping tools before and found them easy to use, intuitive and flexible. There are drawbacks, but one can work around them easily. The DG imagery allowed me to digitize the dense vegetation along the island's western shore. I have mixed feelings working with hi-res imagery. It is the best for extremely accurate work, but sometimes it is too much. If you aren't careful, you can find yourself digitizing the location of individual trees or offshore rocks. That is overkill for my maps.

All other mapping within the Komodo Island group will be taken from ASTER or Landsat ETM+ imagery. A variety of vegetation layers will be used, along with at least two reef layers. All of the islands are outlined and I am currently working on vegetation layers for Pulau Komodo. Wish me luck and...

Enjoy!

Robinson Crusoe Island CL - When This Old World is Getting You Down or Two Other Maps

Robinson Crusoe Island CL

Robinson Crusoe Island - Landsat ETM+ S-17-30_2000 (1:85,000)

Robinson Crusoe Island - DigitalGlobe Image from Google Earth (1:85,000)

Robinson Crusoe Island - EVS Precision Map (1:85,000)

When This Old World is Getting You Down

At times we all wish we could pull a "Robinson Crusoe", find some forgotten spot, seldom visited, yet replete with all the necessities of life - food, water, clothing and shelter. A place without financial pressures, martial woes, busy urban scene and no threat of crime spilling into our fragile lives. I'm not sure that place exists. Alexander Selkirk, the individual Daniel Defoe based his Robinson Crusoe character on, was so lonely by the end of his four year exile, he gladly rejoined the crew of the individuals who had originally abandoned him. His life on previously uninhabited Isla Mas a Tierra was often wretched. His diet was life sustaining, but challenging to gather. His clothing was handmade and unkept. His shelter is reputed to be a cave. He spent many lonely hours at his lookout scanning the horizon for a ship that might rescue him.

With that said, we still wish we could escape to his place. We all know in our heart of hearts we would do better. We would not grow lonely, but using our 21st century knowledge and preplanning, our island life would be a special time to reflect on the world and all of its mysteries and how we fit into them. When we grow tired of our adventure, we would merely dial our satellite phone and be whisked away, back to our previous lives.

Robinson Crusoe Island - Wikimedia Commons

Robinson Crusoe Island - Source Unknown (1:120,000)

Two Other Maps

A map is seldom an entirely unique creation. Robinson Crusoe Island has been mapped many times. Some of these are excellent compositions. I used two other maps to aid in the construction of my map. The first one, found in the Wikipedia article on Robinson Crusoe Island was used to gather feature names. The second map, source unknown, was used to confirm certain feature names and supply any new ones not found on the first "helper" map.

The vector files making up my EVS precision map were created using Landsat ETM+ and DigitalGlobe from Google Earth. The majority of the shoreline was extracted from DigitalGlobe imagery. Where clouds obscured the land, I used Landsat to map the underlying area. The 50-meter contours were derived from SRTM data. There is a problem with the elevations, some of the higher elevations are dramatically different than what they should be. El Yunque Peak is supposed to be 913-meters, but is shown to be approximately 650-meters using SRTM data. I did not correct the erroneous elevations in this version of my map. Perhaps, I'll correct them later.

Robinson Crusoe Island - Chilean Nautical Chart 5410 (1:50,000)

Finally, for all of you sailors that wish to explore Robinson Crusoe Island, the Chilean Hydrographic Office (SHOA) has a nautical chart you might wish to purchase. The above image is a copy of it.

Enjoy!

Thoughts - How Many Uninhabited Islands in the World?

First one must define island. According to the United Nations Convention on the Law of the Sea Part VIII:

1. An island is a naturally formed area of land, surrounded by water, which is above water at high tide.

2. Except as provided for in paragraph 3, the territorial sea, the contiguous zone, the exclusive economic zone and the continental shelf of an island are determined in accordance with the provisions of this Convention applicable to other land territory.

3. Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf.

Now how about nations with lots of islands? Let's list those: Sweden 221,800; Finland 179,584; Canada 53,000; Norway 50,000; Indonesia 17,504; Philippines 7,107; Greece 6,000; Japan 3,000 and Maldives 2,000. In just these nine island rich countries, over 500,000 islands are accounted for. Now for the good news for all of you folks that want to find your own uninhabited island. That place where you can get away from all of the worries of the world - an uninhabited island. Of the 500,000 islands located in these nine countries, only 11, 000 (2%) have a permanent population. That leaves 539,000 (98%) mostly very small islands that have zero population. So take heart all of you Robinson Crusoes, there is an uninhabited island just waiting for you to claim it.

Enjoy!

Wakhjir Valley & Pass AF - Marco Polo Sheep, Silk Road & A Lengthy Mapping Project

Wakhjir Valley & Pass AF

Wakhjir Valley and Pass - EVS Precision Map N-43-35-2000 from Landsat ETM+ N-43-35-2000 (1-100,000)

This map is the culmination of over two weeks of digitizing glaciers, meandering streams, high mountain meadows and many hours of research. During the researching phase I learned about the Great Game, Marco Polo sheep and the Hindu Kush, Pamir, Karakoram mountain ranges. I learned that this valley is an offshoot of the primary valley, the Wakhan that slices between the Pamirs to the north and the Hindu Kush to the south. At the Wakhan's eastern terminus, one could head into the Wakhjir valley and cross over the Wakhjir Pass into China or one could continue east to northeast into Tajikistan and eventually into China. I have always liked the path less traveled, so I elected to study and map the Wakhjir Valley and Pass, a trekkers paradise.

Wakhjir Valley and Pass from Russian Topo J-43-101

First in conducting research, I discovered a site, Poehali!, offering 34,727 free Russian topographic maps (1:100,000). Not only do they offer the topos, but a corresponding MAP file to facilitate georectification. Like a kid in a candy story, I downloaded 11 topos with MAP files. I'm not the greatest at reading cyrillic, but using Google Translate, while comparing the topos to both Landsat ETM+ N-43-35-2000, which covers all of my target area and Google Earth imagery, I was able to make sense of the written data included on the topos.

During my study of the topos, I determined that the Russians had digitized the international borders with a greater accuracy than any of my border sources. Using their topos as base imagery, I digitized new international borders for this area.

The 100-meter contours were generated using void filled SRTM files and Global Mapper. They took about 30-seconds to create once all of the necessary files were loaded. The Russians used 40-meter contours. I think that is overkill. So I elected 100-meter contour intervals.

See all of the glaciers, meadows and streams? That's what took many hours to digitize. All of this data was taken from the Landsat ETM+ N-43-35-2000 imagery. It is virtually cloud free and snow free leading me to believe the imagery was taken during the short summer. It was a matter of how detailed I wanted my map to be. The glaciers were tedious to digitize. I was able to map all glaciers and snow banks that were imaged. The streams were the easiest to map and the least accurate. Landsat, at 14.5 meter resolution, makes that mapping difficult. If the streams/rivers branched, I created a layer called meandering riverbed. My final polygon layer high mountain meadows. The people living in this part of the world are herders. These mountain meadows are critically important as food for their domesticated animals, sheep and goats. These mountain meadows consisted of the lime-green colored vegetation layer located along the valley floors. Needless to say, these three polygon layers were challenging to map and time-consuming to digitize. I wanted to stop and move on to an island, but I counldn't bring myself to do it. Today, I am done! The map can still use work, but I am done.

Wakhjir Pass - Google Earth Pro Image

The above image shows the climb one would need to make in order to get to the pass and cross into China. Apparently, Marco Polo is reputed to have crossed at Wakhjir Pass on his historic trip into China. On the way he recorded a description of the sheep that takes his name, the Marco Polo sheep

Marco Polo Sheep (picture from Snow Leopard Conservancy)

Their numbers are dwindling due to lose of habitat, over hunting and weather extremes. George Schaller has worked tirelessly to save these endangered animals. He would rather not have these majestic animals hunted, but if they must be then the hefty fee of $25,000 per hunt, should be used to benefit the people of the Wakhan. He also is working to establish a 50,000 sq kilometer multinational park that will go far in protecting the Marco Polo sheep and their unique habitat.

Finally, for all of you visiting my site expecting to see my latest island map, I apologize and will endeavor to remedy the situation. For all of you who appreciate a nice map, select the top map image and see the map at full size. Pretty cool, huh?

Enjoy!

Thoughts - DigitalGlobe Imagery in Google Earth and Island Mosaics

Guadalupe Island - DigitalGlobe Mosaic from Google Earth (1:15,000)

I have been gently reminded, agressively scolded and accused of being an image thief. I appreciate the gentle reminders that DigitalGlobe imagery found in Google Earth is still the property of DigitalGlobe, yet is shared with all of us via the Google Earth platform. Let me explain.

A few years back as DigitalGlobe imagery began appearing in Google Earth, I did what many viewer did, I saved copies of high-resolution images of features I found interesting. My dilemma was my interest in islands, which most often require a number of images mosaicked together to create a detailed view of the island that I could then use to create my island maps. After creating my first DigitalGlobe high-resolution mosaic of an island with imagery taken from Google Earth I made my first phone call to Google Earth. I explained how I constructed my high-resolution base image using DigitalGlobe imagery found in Google Earth. I further explained that I used the georeferenced mosaic as my base image from which I would produce an island map for non-commercial purposes. A map that I would post to my website, EVS Islands. In addition, I would also post the mosaic to show readers my base image from which I produced my map. The magic word was "non-commercial". The gentleman I spoke with said that as long as the map was for non-commercial uses, Google Earth had no problem with my efforts, as long as I credited them when appropriate. He added, as far as the DigitalGlobe imagery was concerned, I needed to speak with them. Even though Google Earth hosts the imagery, I needed DigitalGlobe's okay to use their imagery as I was using it. So I called DigitalGlobe.

The individual I spoke with listened to my explanation of how I wanted to use their imagery. The "non-commercial" use of the imagery was again a key element of my intended use. I carefully explained how I took a series of DigitalGlobe images from Google Earth, mosaicked them, georeferenced the finished mosaic, digitized my vector layers of interest and finally posted both my finished map and an image of the DigitalGlobe high-resolution island mosaic to my website. He asked to see my map, the DigitalGlobe mosaic and the image of the mosaic. I emailed them to him. He checked them out and talked with his people. He emailed back that as long as my work derived from their imagery was for non-commercial purposes and I credited them as a source I was good to go.

It has been over two years since that first conversation. I have had a number of subsequent conversations with DigitalGlobe representatives concerning my use of their imagery. They have consistently advised that my use of their product and the crediting I give is acceptable.

Currently, I seldom use DigitalGlobe imagery to construct my island maps. I, almost exclusively use Landsat ETM+ as my base imagery. I hold out hope that somewhere, someone just might want to purchase my enhanced vector shoreline precision maps. So far, it is a "no go", but I hold out hope. In the meantime, I continue to admire the excellent high-resolution imagery made available through the joint efforts of DigitalGlobe and Google Earth. And if and when I need that high-resolution image of a large island, I'll go ahead and construct a DigitalGlobe image mosaic knowing that, so far, both Google Earth and DigitalGlobe representatives have given me the "okay".

Enjoy!

P.S. - Each use of DigitalGlobe's imagery found in Google Earth should be discussed with their representatives. They will determine the actual or potential impact upon their business. Be up front with them, giving a complete description of how you will use their imagery. My experience is that they will support most, not all, non-commercial uses of their imagery copied from Google Earth. The same goes for Google Earth. The problem comes in locating the right person to render a decision concerning your use of their product.

Thoughts - Continuing Yesterday's "Wow"!

Arutua Atoll - Four EVS Precison Layers Loaded into Google Earth

A reader of EVS Islands suggested that I load my island maps into Google Earth. He had taken the Flickr image of Arutua Atoll and created a Google Earth overlay. He did all of this work by manually matching the EVS image to the GE base image. After viewing his work I had another Wow! moment. It turns out Global Mapper creates KML/KMZ files. I have generated GE KML/KMZ overlays previously, but I thought I would try something different. Using the Arutua Atoll vectors, I created a separate overlay for each vector layer using PNG image format's transparency function. I began with my Reef Shallow and the ocean as my first layer without any color transparency.

Arutua Atoll - Base Layer Reef Shallow with Ocean (1:75,000)

The other three layers would rest atop this base layer. The next three layers were EVS Island Polygons, Vegetation and Inland Water. I made the blue ocean the transparent color for these layers. This resulted in overlays consists of 12 georectified tiles per layer neatly positioning an EVS precision island map into GE.

Arutua Atoll - Four Layers Loaded into Google Earth (1:75,000)

Loading these four layers in proper order (Reef Shallow, EVS Island Polygons, Vegetation and Inland Water) one is able to switch layers on and off to view this atoll from a number of unique perspectives. Pretty cool!

Arutua Atoll - Four Layers in KMZ Files

I have posted the four layers and you are welcome to download them and try them out. They are at the following links: Reef Shallow, EVS Island Polygons, Vegetation and Inland Water. Remember to load Reef Shallow first, EVS Island Polygons second, Vegetation third and Inland Water last. The map is at a scale of 1:75,000. That allows you to view the map at the 4.00 kilometer center read using GE's scale bar. If you take the map below that scale it begins to get ugly fast (blurred lines and colors). Hope you find it interesting. Comments are appreciated, especially KML/KMZ types. I am certain there must be a way to load all layers within one KML/KMZ packet and still be able to retain the ability to pile layers on top of each other and exercise control over whether a layer is on or off. Thanks in advance.

Enjoy

Thoughts - Wow! I Didn't Know Global Mapper Could Do That or Discoveries at 4:00AM

Arutua Atoll FP - EVS Precision Map (1:170,000) - Upper Image

Arutua Atoll FP - EVS Precision map (1:75,000) - Lower Image

At first glance, except for a simple coordinate grid, use of a slightly different map scale and the addition of other necessary cartographic trappings, my original image of Arutua Atoll (upper) looks like the Arutua Atoll (lower). Although the images are both sized at 500 x 347 pixels, to fit into this web page, the two images are quite different. The upper image is JPG, whereas the lower image is PNG. I have been using PNG format images for my last few posts. Supposedly, they give one a better, sharper image at a much smaller size compared to JPG. Frankly, for what I am doing (posting an image of a vector map) the JPG format seemed to work fine. That is until I discovered my Global Mapper "Wow!".

I love my finished maps and enjoy sharing them with readers that appreciate my work. I believe most readers are often content to view an island image, read the brief article, ponder it and then go their merry way. As it should be. However, for the intrepid few that really want to check out the island map, that take the time to select the island image and view the original sized image in Flickr, have I got a treat for you!

If you select the lower Arutua Atoll image and follow it to Flickr, you will be able to view my original sized image of Arutua Atoll at a scale of 1:75,000. Global Mapper, my primary mapping software, allows me to capture a screen's contents to an image.

Global Mapper Image Capture

This is not a new discovery, as I have been using this option for years. But this morning I decided to changed the image size from a default of 1264 x 875 pixels to 2578 x 1750 pixels. This change transformed my 1:150,000 scaled island image into a 1:75,000 scaled island image. My original 1:150,000 scaled image will print on a standard 8.5" x 11" sheet of paper. To print my 1:75,000 scaled image would require a 21" x 14" paper. Within Flickr, the reader can view an image that more nearly displays the island at it's EVS precision viewing limits (between 1:75,000 to 1:50,000). Using Global Mapper to create my images, I am able to generate two additional files that allows one to view the island image with appropriate lat/lons (.pngw and .prj files).

My bottom line discovery - by varying Global Mapper's screen image capture size, I am able to quickly generate EVS precision island maps at meaningful viewing scales. And that's my 4:00 AM "Wow!"

Enjoy!