How To Quickly, Accurately and Easily Overlay a Georectified Image into Google Earth Using Global Mapper v9.0

Very Large Kingman Reef - Vector Shoreline View from Google Earth

This is the map that got me started on the mysterious very large Kingman Reef. The sides of the reef are depicted as 140-kms in length. Whereas Kingman Reef is actually a 1/10th of that size. Somebody misdigitized the reef, most probably in the early days of government produced vector maps. Oh, well, that's another story for another time. Meanwhile, let's talk about creating a nifty georectified image overlay and placing it into Google Earth (GE).

Using Global Mapper v9.0 (GM), the process to take an image, georectify it, export it as a KML/KMZ formated file and finally load it into GE is, as my title promises, quick, accurate and easy. How quick - about 2 to 5 minutes, depending on the complexity of the georectifying needed. How accurate - as accurate as you are able to georectify your image against known coordinates. How easy - even a caveman could do it. (I really do dislike that commercial, but it works here.)

Georectify Image

Step 1 - Georectifying an image using GM's process, lets you compare known coordinates (my previously constructed vector files of Kingman Reef) to my image (DigitalGlobe preview image composite of Kingman Reef). I typically create 3+ Ground Control Points (Affine). The GM windows allow for zooming to enable extremely precise georectifying of an image.

Georectified Image

Step 2 - Admire your work! If the image is whacked, you can go back into the georectifying process and fix it. I am an old pro at this, so my images typically line up just fine with my original vector files.

Export Georectified Image as KML/KMZ File

Step 3 - Select File option and Export Raster and Elevation Data. You are given a list of export options. Select Export KML/KMZ.

Format Your Image KML/KMZ File

Step 4 - My georectified image of Kingman Reef is small and is the only image loaded into my work area, so when it comes to KML/KMZ formatting options, I stick with default choices. If this were a very large image (many MBs), I would be able to grid it into manageable file sizes and load each one into GE. I use the KMZ file format. The zipped image and geocoding data take up much less space and load fast into GE.

Name and Save Your KML/KMZ File

Step 5 - Name your file and save it.

Kingman Reef - Landsat ETM+ Image from Google Earth

Double Click File and Enjoy Your Georectified Image in Google Earth

Step 6 - Now for the fun part. (Make sure you have GE loaded into your computer.) Double click your newly created Kingman Reef KMZ file, pause and then admire your work in GE. If you want to share your image overlay with the world, sign into GE and share away. If you just want to admire your handiwork, admire away!

Like I promised - using Global Mapper v9.0, the process to georectify, export and load an image into GE is quick, accurate and easy. Give it a try.

Enjoy!

Thoughts - DigitalGlobe, NGS & Kingman Reef

Kingman Reef - Landsat Image N-03-15_2000 (1-75,000)

Things can heat up at EVS Islands pretty fast, especially when National Geographic requests information about one of my mapping projects. Respected group that they are, they constantly research many areas prior to selecting a few primary areas for more thorough studies. One such area they are studying in depth is Kingman Reef. Since I have done mapping of the reef, one of their mapping team members contacted me and asked about my map of the reef. Needless to say, I was quite excited, yet apprehensive. I knew that the Landsat ETM+ imagery for this reef was not the most revealing. I remembered that in order to construct my EVS precision map I had to "trick" the image.

Kingman Reef - "Tricked" Landsat Image Over EVS Precision Marplot Map (1-75,000)

Using a Blend mode in Global Mapper that made the black colored sea transparent, the reef appeared as a murky yellow smudge. Using this yellow smudge to define the limits of the reef, I mapped it. Comparing my map to a nautical chart of the area, it turns out my EVS precision map of Kingman Reef is a solid effort. After numerous emails back and forth, I sent NGS my Kingman Reef vector files and various images to help them in their study of this reef.

Kingman Reef 10007409B01

Kingman Reef 10007409B01

Kingman Reef - Combined Image (10007318D01 and 10007409B01)

Let's talk about a "perfect world" where we all have access to the best imagery. I should have used DigitalGlobe's exquisite imagery of Kingman Reef to construct my map. A quick scan of DigitalGlobe's available imagery covering Kingman Reef reveals two nearly cloud-free views of the reef. An equally quick "cut and paste" gives me a revealing view of the reef. I could have made the ultimate map for this reef using these two images.

Let's do a "what if". What if my original Kingman Reef project had been constructed from these two DigitalGlobe images? What if I could have told the NGS rep that they were getting the best map availabe for this particular reef, because it was constructed from the best available imagery? What if I could have emailed them a copy of DigitalGlobe's imagery and my vector files for Kingman Reef? What if they would use and credit DigitalGlobe's imagery and my map of Kingman Reef in a future article? I think that is called "win-win".

And let's end this post with a proposition - DigitalGlobe, what would it take for you to make EVS Islands your island imagery charity case? Do you need me to be a non-profit? That is what I intend to do with EVS Islands. If you give me access to your island image archives, I promise I will make the best island maps possible. Using your imagery, I will teach young people the fine art of map making. I promise not to get in the way of your ongoing operations. I will quietly access island images from your archive, construct island mosaics and continue to make the best island maps possible.

Come on, DigitalGlobe, let's make a deal!

Titan's Unnamed Methane Sea

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

Titan's Unnamed Methane Sea without Lat-Lon Grid (1-750,000)

My Titan Island Post generated lots of interest. To finish it off, I went ahead and digitized the shoreline of the unnamed methane sea my previous post's islands are located in. It is one of the largest bodies of liquid known to exist on this moon of Saturn. This body of liquid methane, ethane and nitrogen is about the size of Lake Superior.

Titan Unnamed Methane Sea Base Image PIA10008

Now for my question - Where is 0° longitude on this base image? Are my coordinates correct? I took the original image and georectified it by designating the longitude at the lower center as 0°. I moved clockwise identifying 90°W, 180°W and 90°E. The first latitude below 90°N, I identified as 80°N. Is this sequence correct? If anyone actually knows the proper orientation of the base image, let me know so I can properly georectify my map? Until I find out differently, the above coordinates associated with my map will have to do.

Enjoy!

P.S. - The following is my Titan's Unnamed Methane Sea map with corrected longitudes, thanks to Jason Perry, a Titan mapper.

Titan's Unnamed Methane Sea With Corrected Longitudes

Titan's Islands - Extraterrestrial Islands in a Methane Sea

Cassini Image PIA10008 of Northern Polar Region of Titan

For the past week, I have been patiently digitized vegetation layers of Rapa Island and I needed a break. So I cruised some of my favorite websites, this being one of them, JPL's Photojournal with loads of interesting imagery. The Cassini images of Titan are always a favorite with me. The latest news article states that Titan has 100 of times more hydrocarbons then all of the known Earth's supply. This moon of Saturn is extremely cold (-279 degrees fahrenheit). It is enshrouded in clouds and these clouds are full of methane that rains down onto the surface creating methane and ethane lakes and rivers. Oh, yes, with islands!

Beginning with the above image which is a north polar region view with strips of imaged surface laid onto a lat/lon grid. I geocoded the image, using Global Mapper. I then zoomed in on an island rich portion of a very large methane lake and began digitizing island shorelines.

Titan Sea Compared to Lake Superior - Cassini Image PIA09184

Titan is the second largest moon in the solar system. It has a thick atmosphere made up of hydrocarbons. It's size relative to earth is less than 1/2 the size (1000-meters on Earth = 404-meters on Titan).

Titan Island Group - Cassini Image PIA 100008 (1:1,000,000)

This is the area I selected. It has a number of islands just off shore. The scale I worked at was 1:250,000. These are relatively large islands, The larger islands are 49 kilometers in length. They are big islands.

Titan Island Group - Global Mapper Map (1:1,000,000)

And this is the finished map. Simple, yet other worldly. And, now, this is me saying goodnight. It is after midnight and I have a full day with many eager and rambunctious middle school students. I hope you enjoy this unique map of extraterrestrial islands floating in a methane sea.

Enjoy!

Guadalupe Island MX - A Cloud-Free Image

6 x 16 Grid

Using DigitalGlobe imagery from Google Earth, I selected 96 carefully sequenced screenshots, each at a scale of 1:15,000. From these screenshots I was able to create this complete 4.56MB standalone cloud-free image of Guadalupe Island MX. The 6 x 16 grid shows how the screenshots were arranged to complete the mosaiced image.

A Cloud-Free Image of Guadalupe Island, MX (1:15,000)

The experienced reader knows all one really needs to do is log into Google Earth, center on Guadalupe Island and zoom onto and about the island. So, it is fair to ponder, "So what!"

My image is portable. I load my DigitalGlobe imagery taken from Google Earth, into my mapping software, Global Mapper, and explore the island at my leisure. I made sure to credit both sources, using their standard image trademarks (see very bottom of image).

Guadalupe Island - Cypress Groves (1-25,000)

Now, I can zoom above the cypress groves located in the upper portions of the island...

Guadalupe Island - Southern Portion (1-12,500)

Or head south to view the area of one of two semi-permanent villages located on the island.

Enjoy!

Isla Alboran SP - Isolated Mediterranean Island

I love an island that is located right where an island shouldn't be. That is the case with Isla Alboran. Currently owned by Spain, it is located midway between southern Spain and northern Morocco, right where an island shouldn't be.

Isla Alboran - Multimap Location

I've known about this very small island for some time, but have not been able to find a decent mappable aerial image, let alone, a nautical chart. Finally, I've located a fair aerial image and an excellent image of a NGA NOAA nautical chart of the island. Using these two sources, I created an EEVS precision map of the island at a scale of 1:5,000, to share with EVS Island readers. The source images and EEVS precision map follows.

Isla Alboran - NGA NOAA Nautical Chart (Chart Number Unknown)

Isla Alboran - Untitled and Undated Aerial Photograph

Isla Alboran - EEVS Precision Map from NGA NOAA Nautical Chart (1:5,000)

Isla Alboran has a long history of short visits by Phonecian, Greek, Arab, Venitian, British, pirates and Spanish sailors. They all have made use of this island. Some established navigation warning devices. Others used the island as a base of operation to attack passing ships, as this area is at the center of a rather busy shipping lane. The latest owners, Spain, maintain a functioning lighthouse on the western end of the island.

The interesting information about this island comes from an individual who visited the 36N 3W confluence back in 2003. He gathered a great deal of information about the island and posted it on his confluence report.

The map was very easy to construct. Once the NGA NOAA nautical chart image was georeferenced, I digitized shorelines and reefs using Global Mapper and completed the map using Marplot. It took a total of 3-hours from start to finish. Not necessarily a difficult effort, but thanks to Captian Peter and E. Beniga and their wonderful images, I was able to produce a useful vector map of this isolated Mediterranean island.

Enjoy!

Thoughts - Max and EVS Precision Island Maps

I haven't seen Max for three weeks. Max is undergoing chemotherapy for an especially agressive malignant cancer. When we did talk, he was subdued and distant. His mortality is at the forefront of his thoughts. He is facing the end of his life. Before this awesome and sobering experience, Max loved to visit with any and everyone. He likes to keep an eye on our block. He loves to enjoy the company of his children and grandchildren. He loves to share a beer with Spider and Skip, two long time friends and neighbors. Now Max stays inside of his house deep in thought.

Don't put off your passion. That is the lesson Max is teaching me. We all will leave this interesting world, typically, not alive. So, if you have something you want to do, do it. If you have a product idea that you want to pursue, go for it. If you wish to sail away, get a boat and go. My goal, in life, is to leave with as few regrets as possible.

I will continue making EVS precision island maps. I will continue floating my "poor man's" hi-res island image idea by DigitalGlobe. Their imagery is exquisite and they are open to different ideas concerning their imagery. I have other passions outside of the realm of mapping that I will continue enjoying - the company of my wife, grandkids, children, golf with friends, learning, remaining vibrant amd purposeful.

I wish Max the best and Bon Voyage! I pray that his adventures contine.

Enjoy! and Peace!

Thoughts - DigitalGlobe, Thanks For The Answer. Not The One I Wanted To Hear, But Thanks Anyway.

Starbuck Island - DigitalGlobe Image from Google Earth

If you follow my posts, you know that I proposed a product idea to DigitalGlobe - a "poor man's" hi-res imagery of islands throughout the world. Instead of gigabytes of data and big bucks, these scaled images would consist of a few megabytes of digital data for most islands. I figured a price point of between $25 to $50 per image, with very large islands costing more. Delivery would have been via internet. No one would get rich, but DigitalGlobe's products would have been introduced into markets they currently under serve or do not serve at all. And I would be able to do what I enjoy doing and make a few bucks in the process.

Having many years of experience designing products, developing new markets and determining profitable prices, I knew my product idea faced an uphill, very steep uphill battle. First, who am I and why should DigitalGlobe take my idea seriously. I am a one man shop with the necessary equipment, business experience and passion to handle what I am proposing . Second, who would buy a "poor man's" hi-res image of an island? Many of you would and lots of others, once they learned about it. Just look at all of the interest DigitalGlobe's imagery generates in Google Earth. I am confident that "nickle and dime" Google Earth user would spend $25 to $50 for hi-res island imagery. They will not buy DigitalGlobe's standard products. They are too pricey for their meager budgets. Also, based on the interest in my island projects, my readers - government, business, oil & gas, education, real estate, travel agents, GIS professionals on a tight budget, island businesses, sailors, etc - would buy this scaled hi-res island image product. It would take marketing (which I would do), dependable product delivery (which I would do) and prompt customer service (which I would do).

In addition, I would produce the product. No skin off of DigitalGlobe's business nose. Their resellers won't mind, I'm not taking any of their business away. This product would work for entirely new markets, not ones currently being serviced by DigitalGlobes current product mix.

I have made at least 25 of these scaled hi-res images of islands. They take about an hour to two hours to create. Easy to do. Again, not a problem for DigitalGlobe or their resellers. I would do all of the work.

But, alas, no go! DigitalGlobe's representative said "Great idea!, but....". Don't you just hate that "but". Am I discouraged, not at all. When you have a great product idea, you must hang in there for the long haul. One day, a "poor man's" hi-res imagery of islands will be a reality. Hopefully, mine and DigitalGlobe's shared and mutually beneficial reality.

Thanks DigitalGlobe, for your considerations and, we will be in touch.

Enjoy!

Bikini Atoll RM - Great Dive Destination If You Don't Mind The Glow

Bikini Atoll - LIIM N-58-10 (1:200,000)

I decided to digitize this atoll because the Landsat Island Image Mosaic is cloud-free and it has a certain amount of notiriety connected with nuclear weapons testing and population displacement. As a youngster, I watched rebroadcasts of one of the blasts on TV. It was probably the Bravo blast, the one that left the big hole in the northwest portion of the reef.

The islanders are still displaced. It seems they tried to reestablish themselves back in the 70's. After awhile they were beginning to glow (figuratively speaking). They were taken off of their home and scattered onto other islands. Now, tourists are allowed to visit, along with divers and fishermen. The island and it's waters have been deemed safe for short stays. Just don't drink the groundwater, eat the coconuts, land crabs or fish. One advantage if you stay for a long time - you won't need a lantern at night, your radioactive glow will provide sufficient illumination. Just a joke. I know that folks earning their livelihood from tourists, divers and fishermen will resent my "glow" remarks. I apologize to them. But, the U.S. military screwed up when they blasted holes in this atoll. 60-years later, I still say, "Shame on you."

Bikini Atoll - EVS Precision Map (1:200,000)

Enough about my personal gripes. The EVS precision map of Bikini Atoll was a fairly fast project to complete. The digitizing took 8-hours over a period of 2 days. The map assembly and posting has taken another 2-hours. 10-hours from start to finish for an island of this size is good. The reef, thank goodness, was relatively simple to digitize. Some reefs are quite complex and require many layers of information. This reef consists primarily of three layers - EVS Reef Shallow, EVS Reef Middle and EVS Reef Deep. They are distinguished by their respective shades of blue. The majority of the lagoon is classified as EVS Reef Deep. I used only a single vegetation layer, EVS Vegetation Mixed (Hi-Lo). I use this classification on most Landsat imaged islands with a mixture of palms and other trees along with shrubs and low-lying plants. When I am able to study a DigitalGlobe hi-res image along with the Landsat, I am able to make better vegetation layer classifications.

I still have work remaining on this project - EVS Reef Awash where visible waves appear along the outer reef and confirmation of individual motu names When I am satisfied with the outcome, I will repost the map. Until then...

Enjoy!

Nukutavake Island FP - Third Time Posting is the Charm

Nukutavake Island - Landsat Image S-07-15_2000 (1:25,000)

Nukutavake Island - Marplot Map (1:25,000)

Nukutavake Atoll - EVS Precision Map (1:25,000)

The second map is the new and improved version of my EVS Precision island maps. Not only have I made better use of the text fonts found in Marplot, but I've added a North Arrow. Also, and most important, I've adjusted the colors. I promise that any of you creating a large body of original maps will find yourselves constantly tweeking the colors. This particular color pallet is probably version 101. Seriously, colors are the ultimate subjective layer of information one places on a map. Quite often they reflect your moods. If you are having a bad day, wierd colors result and a good day leads to peaceful earth-tone pastels.

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Nukutavake Island (Noukoutawake) is a small island, of coral formation, located about 8 miles NW of Pinaki. It is about 3 miles long in an E-W direction, and is wooded except at its E end. There is a radio station on the island.In May, June, and July the population of this atoll moves to Vairaatea, and in August, to Pinaki to harvest copra.

(SD Pub-126)

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Group: Centre East Group
Archipelago: Tuamotu Archipelago
Country: France - French Polynesia - Tuamotu Is.
Region: Oceania 18
Lat: 19.28º S Long : 138.78º W
Area: 4.5 sq. km
Altitude: ? m
Depth to nearest land: 3000 m
Nearest island: 14.5 km @ 143° (Atoll Pinaki)
Group: 980 km
Nearest continent: South America
Distance: 5400 km Isolation Index: 108

ISLAND TYPE: low coral Natural Protection Indicator: 2
CLIMATE: tropical
CATASTROPHIC THREATS: cyclones Threat Indicator: 1
ECOSYSTEMS: Coconuts; fringing reef Number of Ecosystems - Terrestrial: 1 Marine: 1
Percent shoreline: Coral Reef: 99% Mangrove: 0%

HUMAN OCCUPATION: Uninhabited, ?
Population: 0 Density: 0.0 persons/sq. km
Major Human Activities: coconut plantations
Percent population in agr/mining/fishing: 17% Human Threat Indicator: 1
Gross Domestic Product: $ 7236 per capita Economic Pressure Indicator: 4

DATA RELIABILITY: Data Rel. Indicator: 1

HUMAN IMPACT INDEX HI: 5
CONSERVATION IMPORTANCE INDEX CI-Terrestrial: 5 Low
CI-Marine: 4 Low

Last updated: 27/02/89

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Nukutavake (aka Queen Charlotte Island) is an atoll located in the eastern part of the Tuamotu Archipelago at 138°48’ west longitude by 19°17’ south latitude. It is 1,125 kilometers (699 miles) from Papeete. British Captain Samuel Wallis was the first European to discover this atoll in 1767. This is a unique atoll because although it is flat and of coral formation, it has no lagoon. While some accounts claim there are no signs of there ever having been a lagoon, other accounts claim that what was once a lagoon has been entirely filled in by sand and limestone particles from the external coral reef. Part of the atoll is covered by dense vegetation, while the rest has a coconut tree plantation covering some 800 hectares (1,977 acres). Nukutavake is 5.2 kilometers (3.2 miles) long. Its width ranges from 450 meters (1,476 ft.) to 1.3 kilometers (0.81 miles) in the director of the village. The atoll covers an area of 360 hectares (890 acres).

The village, located in the northeastern part of the atoll, has some streets and a main road from the coast and the coconut plantation. There is an aerodrome 800 meters (2,625 ft.) south of the village, linking the atoll to the outside world. There is a whaleboat dock opposite the village that allows for transferring people and cargo from and to cargo ships that anchor offshore. The 1996 census recorded a population of 196 persons. The atoll is the administrative center for a district made up of the associated districts of Vahitahi and Vairaatea.

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This island was mapped quickly. Not carelessly, but quickly. It took about 1-hour to digitize and create the map. Another 30-minutes to post and comment.

Also, the discovery of the additional island information from the web site of the President of French Polynesia (what a job!) will enhance the information associated with this island. I did send him an email to present my website. However, no reply as yet.

Enjoy!