Clipperton Island FR - It Has Been a Long Time Between Maps and Why.

  Clipperton Island - DigitalGlobe Image taken from Google Earth

  Clipperton Island - EEVS Precision Map (1:17030)
Taking advantage of DigitalGlobes hi-res imagery found in Google Earth, I was able to redo my original EVS precision map of Clipperton Island into an EEVS (Extremely Enhanced Vector Shoreline) precision map.  Clipperton remains a popular, but long-distant fishing destination for long range boats from San Diego, my home town.  It is also one of the only French possessions located in the Pacific Ocean.  Besides the fishermen, DX'ers love to transmit and receive QSL's from this remote atoll.

I have been a busy map maker these past four months. My day job, as many of you know, is a middle school teacher. That means that every weekday I attempt to teach meaningful Social Studies lessons to a room full of less-than-eager students. This year I am trying something different, I teach Social Studies lessons using both Google Earth and Quantum GIS mapping software.

For example, my 6th grade students have just begun a unit on China.  As an entertaining but hopefully, useful exercise, I listed 15 cities, tourist locations, landmarks, etc., found in China.  The students had to locate them in Google Earth, take a screen shot, id the image, place it in a folder on their virtual desktop, and when complete submit the folder to me using Shared Documents.  My objectives - students get an introduction to the geography of China, they use Google Earth as a learning tool, they enhanced their image handling skills, and they have fun with geography while learning.

We will work with QGIS (Quantum GIS) during this unit.  I always like the students to create a vector layer of information on top of a georectified image.  This sort of project requires a great deal of patience and usage of a teaching method I call the "Louder Method".  If they don't get it the first time, just say it louder the next few times.  I'm just kidding.  Really.  REALLY!!

Enjoy!

How To Digitize Vegetation and Land Layers using Landsat Imagery at 1:12,500 Scale

Faaite Atoll FP - Comparison - Landsat Image, EVS Precision Map, DigitalGlobe Image (1:12,500)

I keep telling all of you that I typically digitize off of Landsat imagery at approximately 1:12,500 scale. Checking out the above montage you will see a Landsat image of a portion of Faaite Atoll FP. Beneath it are two layers of information I digitized using Landsat as base imagery, vegetation and land. The final DigitalGlobe image from Google Earth is of the same stretch of atoll. The Landsat image has a green hue over all of the land and vegetation features. However, having digitized so many islands the sand or low vegetation, which I classify as land is identifiable. My Landsat derived vegetation layer is a decent approximation based on the vegetation shown on both Landsat and DigitalGlobe's hires imagery. The digitized land layer, I believe, is a strong match.

Why should one care at what scale one is able to digitize using Landsat as base imagery? Ask any photogrammetrist and they will tell you Landsat is reliable between 1:125,000 to 1:62,500. Each pixel covers a ground area of 14.5 meters by 14.5 meters. However, working at 1:12,500 does not render an image useless, but allows one to discern details in a rough but usable fashion. I can't make out individual trees, but I can identify stands of vegetation and most often the density of that vegetation. The most difficult feature on an atoll to reliably digitize is that portion of the reef which is awash depending on the time of day (high tide or low tide) and the amount of vegetation found growing on the reef. It is often difficult to determine whether the feature is above water land or below water shallow reef. Typically, if I'm uncertain I classify the feature as above water land.

Who knows, one day you might want to try your hand at island map making and you will want advise as to what scale you might expect to work at using Landsat as your base imagery. Digitizing at 1:12,500 should work just fine. Give it a try.

Tepoto Nord FP - A Redo of a Redo of a Small Coral Island

Tepoto Nord FP - Landsat Image from S-07-10_2000 (1:20,000)

Tepoto Nord FP - ISS002-E-8862 Image

Tepoto Nord FP - EVS Precision Map (1:20,000)

My first map of Tepoto Nord was completed on March 31, 2006. I used Landsat as my base imagery. Most of my finish work was done using Marplot, a fine poor-man's GIS program. In December 2006 , I came upon the ISS image of Tepoto Nord. I decided to redo my original work using the ISS imagery to digitize from.

I look at my completed Tepoto Nord mapping project today and contemplate how far my map making skills have progressed. My digitizing of shorelines, vegetation and reefs remains fairly consistent. I routinely work at between 1:12,000 to 1:8,000, depending on my base imagery and the ultimate objective for my map. I am content to map four to five layers of information taking what Landsat is able to provide. The first time I mapped this island, I remember being frustrated by the Landsat imagery. The odd colors and blurred appearance of the island made digitizing problematic. Eventually, I came upon the ISS image and was able to redo my mapping of this small island in a more satisfactory manner. I reposted the map and base imagery in December 2006 and gave this small island no more thought.

That is until I received a question from an EVS Islands reader. He wanted to know everything he could about this small island. I answered that he should contact Alex W du Prel, publisher of Tahiti-Pacifique magazine. If anyone could give information about this small island, Alex is the man. After answering the reader's question, I checked out my map of the island. Unsatisfactory! The map presentation choices I make today are far superior to those I made in 2006. I decided to redo my redo of this small coral island.

Tepoto Nord FP - DigitalGlobe Image from Google Earth (1:12,000)

Tepoto Nord FP - EEVS Precision Map (1:12,000)

I checked out Google Earth, as almost all of the islands within the Tuamotus are covered by DigitalGlobe's hires imagery. Sure enough, Tepoto Nord has excellent, cloud-free imagery from which I could redigitize various layers of information with a high degree of confidence. Seven layers of information later my redo of the redo is done. Since I have no designs to offer the map for commercial purposes, I decided to use DigitalGlobe imagery as my base imagery. I have worked on this redo of a redo for about two weeks. Not because it was particularly difficult, but I've been busy with school. Finally, I have a Saturday with no pressing projects. Only this, to finish my Tepoto Nord FP map. Pretty nice, huh?

Enjoy!

Marutea Atoll Nord FP - An Uninhabited Atoll...Kind Of

Marutea Atoll Nord FP

Marutea Atoll Nord FP - Landsat ETM S-07-15_2000 Image (1:150,000)

A portion of the Landsat ETM+ image looks great, the other portion is cloud covered. If I had only used the Landsat image to create my EVS precision map, it would have been an incomplete effort. Fortunately, ISS imagery helped to fill in the gap.

Marutea Atoll Nord FP - ISS006E37438 Image Modified (1:150,000)

First I had to rotate the ISS image and georectify it to my Landsat base image. I was able to do it after much tweaking of the ISS image it was positioned properly for my mapping purposes. Many of the coral heads, which I classify as shallow reef, were derived from the ISS image.

Marutea Atoll Nord FP - EVs Precision Map (1-150,000)

And here is the finished map! If one requires hi-res imagery, it can be found in Google Earth. Located at the channel leading into the lagoon are a few houses. I suspect they are used by coconut or black pearl harvesters. Although the island is uninhabited, people frequent the atoll doing the things that people do, harvesting resources.

Looking at the DigitalGlobe imagery found in Google Earth, large stretches of the island appear to be without a sand covering. It looks as if the island was washed over by a typhoon or a storm surge. Perhaps someone with first hand knowledge might share more about this uninhabited atoll...kind of.

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 - 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 - Just Do It!

Just Thinking About It

Back in 1964, I was checking out reference books at a library. I happened upon a Geographical Dictionary. Leafing through that dictionary, I came upon an entry describing a small obscure island, Eiao. The entry stated that this island was 8 miles by 4 miles with elevations of 3,000 feet in the island's central plateau. At one time the island was inhabited. During the later part of the 19th century, the French used the island as a prison. Now the island was overrun by feral animals which were decimating what little native vegetation remained.

From that single incident came my fascination with islands. Like many people with a keen interest in islands, my reasons are many and most of these reasons having nothing to do with geography (stress, explorer, master-of-my-domain, etc.). What I discovered early on was the absence of readily-available maps. There were a few WW-II maps in out-of-print books, but no available collection of island maps.

Scripps Institute of Oceanography and Maps

That led to Scripps Institute of Oceanography and their excellent map collection. SIO does ocean-oriented research throughout the world. Consequently, they have a paper map collection of the world oceans and islands that rivals the best in the world. During the early 1980s, I spent many weekend hours pouring over this collection of maps and charts. The map librarian and I became acquainted and he allowed me access to their entire map and chart collection. It was both a joy and a curse, a sensory overload. I had access to every island paper map in the SIO collection and all I could think was, "So many islands, so little time."

My first idea was to amass my own collection of paper maps. This was the pre-digital and pre-affordable computer age. I would need to copy thousands of maps. No way! At 15 cents a copy, it just wasn't practical or affordable. I thought I could trace the shorelines of islands. Too many islands, too complicated, too time-consuming. Again, No way! So I stopped. That's right, stopped any island map aquisitions activities and went about my non-island map life.

Affordable Computers...

Which takes us to the late 1990s, the time of affordable computers, mega-storage, www and information everywhere. This was a time of digitizing paper map collections and one of the first was the Perry-Castenada Map Collection at the University of Texas. I'm not sure of the precise date that their collection went on-line, but many paper maps were freely available as raster images. Anyone could download them and amass their own digital map collection. During this time, I downloaded 100s of island maps. It was great fun, but I knew there was more. Raster maps were okay, but what about vector maps. They were considerably smaller in size and offered greater flexibility. In 2001, I went the way of the vectors.

The Way of The Vector

Not having money to spend on software, I became the master of the freeware and shareware world. I finally settled on Marplot for my mapping software and World Vector Shorelines from the NGDC Coastline Extractor. I remember downloading 100s of vector tiles onto 1.4MB floppies, taking them to my computer where I uploaded them into Marplot. It took about a month and I managed to load all of the world shorelines at 1:250,000 scale, 20,000+ placenames of major cities, 86,000+ placenames of islands and various other opportunistic layers of information.

Free Landsat ETM+. Global mapper and Google Earth

It was about three years ago that I discovered free Landsat ETM+. Turns out Bill Clinton, at the urging of Al Gore and others, made Landsat ETM+ georectified photo mosaics available for free. I spent that summer downloading all of the Landsat ETM+ images that covered oceanic islands of the world. It was at this time that I actually spent hard currency on my mapping passion and purchased Global Mapper. This software can load Landsat ETM+ in MrSid format effortlessly and has an above average digitizing toolkit. The final piece to my mapping project puzzle was Google Earth with DigitalGlobe imagery. As more and more hi-res imagery comes online, the quality of my work will be greatly enhanced.

What Now? Just Do It!

Since 2004, I have been making island maps. Since 2005, I have been posting my island maps on to my blogsite. Since 2007, I have been producing high-quality vector maps of islands. To date I have produced close to 200 maps covering easily 1,000+ individual islands. People ask why I give these maps away. They suggest that I need to charge for my work. I say to them, "We'll see." What I mean to say is, "No, I will not charge for my raster images of maps." If you want them, you can download them and use them. Just give credit where credit is due.

Today and In To The Future

I would love to guide an international team of neo-cartographers to complete a world shoreline map, including islands, using Landsat ETM+ imagery. Yes, I know all about the NGA Prototype Global Shoreline. Trust me, my world shoreline will be more accurate. I would love to guide that same team of international neo-cartographers in fashioning the next-generation Digtal Chart of the World. I would love to make all of this information available for free. In the spirit of Google, free.

So that is what I do. I continue to make high quality island maps and post them to my website. I continue to actively solicit serious offers toward sponsoring a world shoreline mapping project using an international team of neo-cartographers. This passion is what drives me forward and forward is always the best direction to be moving.

Enjoy!

Vatican City - A Sovereign State and an Urban Island

Vatican City - DigitalGlobe Image Mosaic from Google Earth (1-580000)

My evening began innocently enough. A friend wanted to know something about an island in the Northern Mariana Islands. My first search involved Google Earth. After a few hours devoted to looking at islands scattered about the Pacific Ocean , I began to wander, you know "Google Earth wandering". Before long I was following the southern coast of France and Italy. And before I knew it, I was looking at Vatican City. Follow the preceding link and you can read an article about Vatican City. What I want to discuss is inspiration and hi-res imagery in Google Earth.

As I viewed Vatican City it appeared as a small island (44 hectares). The borders used in GE poorly track the city boundaries. I knew I could do better. First I needed to construct a DigitalGlobe image mosaic from which I could digitize a new border, a more accurate one. I could have drawn the polyline in GE, but what fun is that when you can spend a few hours constructing your very own image mosaic. I took a total of 30 screen shots at a scale of 1:250 from GE. Using ImageForge software I created a canvas 6000 x 4000 pixels to accommodate my finished mosaic. Using Irfanview software from which to select portions of images, I worked through 30 cut and pastes, ending up with the above image. My final image is 12.5 MBs and is 4980 x 3560 pixels in size. After georectifying, I zoomed about Vatican City to my heart's content. Maybe I'll try my own map of Vatican City later and maybe not.

It is just fun to construct one of these DigitalGlobe image mosaics using their hi-res imagery found in Google Earth. Take care and...

Enjoy!

Eiao Island FP - Still Revising My Maps

Eiao Island - Google Earth Image (1-60,000) as of March 2007

Eiao Island - Digital Globe Mosaic (1-60,000)

Google Earth and all of us end users have sure benefited from their relationship with DigitalGlobe. From the first blurry image in GE to the exquisite DG mosaic, Eiao Island has never looked better.

Eiao - Map (1:60,000) as of May 2006

Eiao Island - EEVS Precision Map (1-65,000)

My first map of Eiao Island constructed from WVS vector files. In May 2006, I had yet to discover the full extent of resources available to all of us neo-cartographers. I routinely use Global Mapper as my mapping platform. My imagery comes from my Landsat ETM+ library of all the world's shorelines or from DigitalGlobe imagery found in Google Earth. My final island map products are getting better and better. And that's good.

Enjoy!

Coronado Islands MX - For The Birds and Fishermen

View Larger Map

Coronado Islands - Spot Image from Google Earth (1-35,000)

Coronado Islands - Other Precision Map Using Spot Image From Google Earth (1:35,000)

Located about 25 kilometers south of the entrance to San Diego bay, these Mexican islands are often mistaken as US possessions. Most San Diegans know of these islands and a few of the stories associated with them. For instance, we know that there was a gambling establishment on South Island that was a going concern well into the Depression. We know that the islands were used as a haven for Prohibition smugglers. Today there is a small Mexican military detachment stationed on South Island to keep an eye out for human smugglers and fishing poachers. The islands are visited daily by fishermen, divers and numerous sea birds, especially brown pelicans.

I first saw the islands as a young boy back in 1954. From that perspective they appeared to be two buffaloes. To others they look like coffins. To me they are always a welcome site.

The map was constructed from an image mosaic I created using the Spot image found in Google Earth. From this georeferenced mosaic I was able to work at a scale of 1:5,000. As a result, the shoreline details are excellent. I tried using SRTM 30-meter to generate contours and the results were not satisfactory. I knew of a series of geologic maps of the islands containing 20-meter contours on a San Diego Geology website. I georeferenced the contour containing images and copied the 20-meter contour intervals. When necessary, the contours were adjusted to align with the underlying Spot image.

Because my digitizing work was done at a scale of 1:5,000, the zoom factor for these islands gives one excellent details. I would suggest using Google Earth imagery to take a detailed tour of the islands. To enjoy an excellent map of the islands, this is the place.

Enjoy!

Isla la Plata - Ecuador's Bird Island

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Isla la Plata - Landsat Image S-17-00_2000 (1:20,000)

Isla la Plata - DigitalGlobe Island Mosaic from Google Earth (1:20,000)

A group that removes feral animals from islands asked if I could help them with a map of Isla la Plata located off the coast of Ecuador. I said sure and began to search for a map or image of the island. The only map was something that was painted on a sign posted on this island. Not very accurate, but colorful. I tried the Landsat ETM+ image and found it to be obscured by clouds at a number of points on the island. I finally looked into Google Earth and found the DigitalGlobe image that covers the island. Except for clouds over the northern tip of the island, the image is exquisite. To create the above mosaic which is 12.4MBs and 4500 x 4120 lines, I copied 24 images (1280 x 911) and pieced them together. This image was georectified using Global Mapper, Landsat ETM+ and Google Earth coordinates.

Isla la Plata - Other Precision Map (1-20,000)

This is the resulting map. The parties wanting to use the map did not require a vegetation layer so all that I had to map was the island shoreline. That took about 4-hours to map, not just the shoreline, but all of the offshore rocks as well. Finally, using SRTM 90-meter and 30-meter data, I generated 10-meter contour intervals. As so often happens, the 10-meter to 30-meter contours ended up in the ocean. I spent another 4-hours adjusting contours so that they resided on the island and not in the deep blue sea.

This map is done. I hope the party using it will find it helpful. I reminded them that they could not publish this map without permission from DigitalGlobe. It is my experience that DigitalGlobe is very open to allowing maps derived from their data to be used for educational research and perhaps for the removal of feral animals from fragile islands.

Enjoy!