EVS-Islands

Titan's Methane Seas - Radar Swaths PIA 10008 Modified

Reviewing my RSS science links, I came across an article describing Titan's liquid methane seas that were imaged by the Cassini spacecraft. The article contained a link to the base image of these seas, PIA10008. Studying these seas, I noticed what looked like islands. There they were swimming in a methane sea. Not one or two, but an entire archipelago of islands scatter about the sea. I figured I would construct a map of the islands. To begin my extraterrestrial island mapping project, I downloaded the base image, PIA10008. I was able to determine the appropriate lat/lon grid and this allowed me to georectify the base image. Using Global Mapper v9.01 software, my favorite digitizing software, I created vector shorelines for the islands within the methane sea. A few days later, I went ahead and digitized the entire shoreline of this unnamed methane sea.

Titan's Unnamed Methane Sea

I selected a funky mustard color for the land and pretty blue for the sea and rivers. The resulting map was posted and then the world came to view my creation. I have made so many maps of islands that I failed to appreciate just what I had fashioned - a first map of an extraterrestrial sea and islands. I feel I've made more satisfying maps of islands, but this other worldly depiction is still widely viewed, vigorously discussed and enjoyed by thousands of readers.

Life is swell when you are able to create something appreciated by an audience of first time visitors to your website. I am pleased that my efforts have fired the imagination of island lovers throughout the world.

Enjoy!

Labels: Cassini, Global Mapper, NASA, Titan

Posted by Mr Minton at 4/18/2008 06:50:00 PM | Permalink | Comments | links to this post

View Larger Map

Gough Island - Landsat S-29-40_2000 (1:65,000)

Gough Island - EVS Precision Map with 50 Meter Contours (1:65,000)

Gough Island, a dependency of Saint Helena Island, is located in the distant south Atlantic. Today, South Africa maintains a weather station on the southeastern tip of the island. This is a blustery portion of the Atlantic and the island is subject to weather extremes. For more detailed information follow this link.

I actually digitized the island shoreline last summer. I wanted to fancy the map up, but had other chores to do. Now that I fancy my maps with Marplot, I finished this map tonite, April 15th - Tax Day. Taxes are a drag, but my map is nice.

Enjoy!

Labels: Atlantic, EVS Precision, Global Mapper, Landsat ETM+, Marplot

Posted by Mr Minton at 4/16/2008 12:34:00 AM | Permalink | Comments | links to this post

Lukuga River - Entire River Overview Landsat S-35-05_2000 (1:1,000,000)

I am done! To manually digitize a river is a challenge. Lots and lots of twists and turns make up the river's shoreline, as well as water-inundated areas. One frequently must decide where the river shore ends and the river begins. After one completes the river shore, then comes the islands. The Lukuga River has almost 1,000 island polygons. The majority of this polygons are very small, but the conscientious map maker digitizes every visible feature that might possible belong to a certain layer. Let's take a look at what I was able to accomplish.

Lukuga River - Entire River Overview EVS Precision Map with 100-Meter Contours (1:1,000,000)

At this scale the effort might not look very impressive. However, having digitized this east-west flowing African river and it's many islands, it is an impressive effort. I've added SRTM generated 100-meter contours. Lake Tanganyika makes up the eastern edge and the Lualaba River is the western edge. Now for a few close-ups.

Lualaba and Lukuga Confluence - Landsat S-35-05_2000 (1:50,000)

Lualaba and Lukuga Confluence - 3D View Landsat S-35-05_2000 (1:50,000)

Lualaba and Lukuga Confluence - EVS Precision Map (1:50,000)

This series of images show the confluence of these two rivers. The Lukuga has meandered over relatively flat westward sloping terrain for about 200 kilometers before joining the Lualaba. The large island at the western end of the Lukuga is a water inundated feature that was a challenge to digitize. Water and land quite often blend making digitizing difficult.

Lake Tanganyika and Lukuga Confluence - 3D View Landsat S-35-05_2000 (1:250,000)

Lake Tanganyika and Lukuga Confluence - EVS Precision Map with100-Meter Contours (1:250,000)

These images show the Lukuga flowing from Lake Tanganyika through the town of Kemba. The Landsat image shows agricultural lands throughout this area. The river then courses through a cleft between the hills to the west.

I'm going to go ahead and post this. I have one more series of images to include, but I'll add them when I return after a date with my wife. I hope you all find this effort interesting. I, myself, find it extremely satisfying. This river is mapped at EVS precision, manual digitizing from Landsat ETM+ 14.5-meter resolution base imagery.

Enjoy!

Labels: EVS Precision, Global Mapper, Landsat ETM+, Lualaba River, Lukuga River, riverine islands

Posted by Mr Minton at 4/13/2008 12:12:00 PM | Permalink | Comments | links to this post

Locations of 506 Crude Oil Refineries

First, I'd like to credit RoadRunner for his original Google Earth (GE) post titled "The World's Crude Oil Refineries". This data was compiled and posted to GE in October 2005. In his post he references a list of Oil Refineries in Wikipedia as his source. Whatever his source, I wanted the locations of these refineries and bpd production figures so that I could map them in Marplot.

I took his data, which was in the form of a KMZ file. Then I loaded it into Global Mapper and exported the data into a SHP file format. I took the resulting DBF file and modified the data so that my Marplot record would read - refinery name and 2005 production in bpd. I connected this with the refineries lat/lon. I created a layer within Marplot called Refineries, imported my modified file and now have the locations of 506 Crude Oil Refineries in my EVS Projects map file. Oh yes, I do have the original data in SHP and KMZ/KML formats. If you want to see RoadRunner's original data, follow the above link. If you want to see my data, look at the map. If you want a copy of the file from which to create your own layer of information, drop me a line and tell me your desired file format and I'll see what I can do.

The original file is the work of RoadRunner. He gets all of the credit or non-credit. The production figures for many of these refineries have changed. I don't have the new figures, that is for you to gather. Some of the refineries within the list are not refineries at all, but something else. However, if you are an energy industry person, this is a great starter list.

Enjoy!

Labels: Global Mapper, Google Earth, Marplot, oil refineries

Posted by Mr Minton at 4/09/2008 06:25:00 AM | Permalink | Comments | links to this post

Lindisfarne island -InfoTerra Ltd and Bluesky Image from Google Earth

Lindisfarne Island - EEVS Precision Map (1-20,000)

As a college freshman, many years ago, I studied the impact of this island on Western Christendom. Sts Aidan and Cuthbert's early efforts at sustaining the Christian missionary efforts into England were important players toward it's eventually widespread acceptance. Some of us celebrate their efforts, others curse them. So goes the world. If you want more information on Lindisfarne Island follow this link . Let me talk about the base image and map.

The base image is a mosaic extracted from Google Earth using Infoterra and Bluesky imagery. It gives one a cloud-free view of the island. Maybe, too clear an image. I realize that this area is subject to major tidal flows. At times the island is an isolated island with both the causeway and surrounding sands under water. Other times the island is an extension of the shore. I believe the imagery captures the land-linked island.

I intend to make a couple of corrections and at least one addition to the map. Where the causeway links to the island is a stretch of shore that contains EVS Sparse Vegetation (Low). In this version of the map it shows up as EVS Land Bare. Also, I want to add an EVS Feature identification for Lindisfarne Island castle. I believe the map is initially a good effort and because it is vector based, one is able to zoom and modify to their heart's content.

It is nice to complete an island map. After all, that is what this site should be all about.

Enjoy!

Labels: Bluesky, EEVS Precision, Global Mapper, Infoterra, Lindisfarne, UK

Posted by Mr Minton at 3/22/2008 10:36:00 AM | Permalink | Comments | links to this post

Marplot Mapping Software

Marplot Mapping - Census Tiger Data for Prince William County VA

Mr MInton's World Shoreline Marplot Map

This post is a discussion of some of the things that one can do with Marplot, and they are many. This is not a discussion of how seamlessly Marplot works with the Census TIGER files. It is a discussion of Marplot's ability to hold a large number of vector and raster layers of information within a user defined map. My map is called World Shoreline and it currently contains 200-plus unique layers of information. Marplot allows me to switch layers on and off as I need them. I control the layer's range, color, line width, fill, and symbol. I can override my choices at any time and modify layer appearance. Marplot let's me take polylines and create polygons. In addition, it easily allows for the creation of islands of information within larger islands. Oh, by the way, it's free.

Marplot can import BMP, PNG, JPG and a few other raster image formats. However, direct import file options are limited to DAT file format (ARC Ungenerate), TXT file and MIE format (Marplot's own format). One can import SHP files using a freely available piece of conversion software called shp2mie. Marplot's digitizing features are functional, but limited.

I began using Marplot over 5-years ago. It was free and seemed to offer some useful possibilities. As I gained more and more experience working with it, I've come to appreciate the breadth of options available in it. It is a "poor man's" GIS package. I am aware of extremely robust Open-Source GIS packages. I have tried them and for my work they are too complex. Marplot is the ticket for me.

However, if I had to depend solely on Marplot as my digitizing software, I am quick to acknowledge that the quantity of my EVS Island maps would be a fraction of what I am able to currently produce due to the serious limitations of Marplot as a digitizing platform. My digitizing and raster image manipulating software of choice is Global Mapper. Global Mapper allows me to load a number of Landsat ETM+ images quickly and easily. Within seconds, I am digitizing shorelines. It has many additional features and is used by GIS professionals to accomplish quite demanding and complex mapping tasks.

I have tried other mapping packages, but I keep coming back to Marplot. Oh, well, as they say, "dance with the one who brought you." and Marplot maps are an integral part of every one of my EVS-Islands projects.

Enjoy!

Labels: Census Data, Global Mapper, Landsat, Marplot

Posted by Mr Minton at 3/03/2008 06:40:00 AM | Permalink | Comments | links to this post

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!

Labels: DigitalGlobe, georectify, Global Mapper, Google Earth, Kingman Reef, KML, KMZ

Posted by Mr Minton at 2/28/2008 06:20:00 AM | Permalink | Comments | links to this post

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

Labels: extraterrestrial island, Global Mapper, Marplot, methane sea, Saturn, Titan

Posted by Mr Minton at 2/24/2008 01:26:00 AM | Permalink | Comments | links to this post

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!

Labels: extraterrestrial island, Global Mapper, Saturn, Titan

Posted by Mr Minton at 2/21/2008 11:28:00 PM | Permalink | Comments | links to this post

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!

Labels: DigitalGlobe, Global Mapper, Google Earth, Guadalupe Island

Posted by Mr Minton at 2/14/2008 04:48:00 AM | Permalink | Comments | links to this post

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!

Labels: EEVS Precision, Global Mapper, Marplot

Posted by Mr Minton at 2/11/2008 10:08:00 PM | Permalink | Comments | links to this post

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!

Labels: DigitalGlobe, EVS Precision, Global Mapper, Landsat ETM+, LIIM

Posted by Mr Minton at 2/05/2008 04:26:00 PM | Permalink | Comments | links to this post

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!

Labels: atoll, EVS, Global Mapper, island, Landsat, map, Marplot, Pacific, Polynesia, Tuamotus

Posted by Mr Minton at 2/03/2008 09:45:00 AM | Permalink | Comments | links to this post

The Effect of Blends and Backgrounds on LIIMs

I most often digitize from LIIMs using Global Mappers's Blend Mode called No Blend (Slide 1). No Blend shows the various land and water features as Landsat ETM+ mosaics intended them to look - somewhat natural. For most projects, this image works fine. However, atolls present some unique challenges - What is above water and what is below? What is shore vegetation and what is bare earth that looks like shore vegetation? Where does the land end and the reef begin? Like I said, unique challenges.

When I encounter these challenges, I use a couple of different options - 1) changing the background color to either Yellow (R-157,G-191,B-202), Pink (R-255,G-128,B-192), Light Pink (R-255,G-193,B-224) and Blue (R-157,G-191,B-202) and using two new Blend Modes - Difference and Color Burn. Let's talk about Difference first.

Tauere Atoll - Blend Mode Difference and Blue Background

Difference creates a soft looking false color image that makes certain atoll features stand out, for example the sand. It is also a great way to distinguish underwater features. I always switch between No Blend and Difference to visually confirm my work.

Tauere Atoll - Blend Mode Color Burn and Blue Background

Color Burn creates a sharp separation using false colors. The blue background and Color Burn allows for some potentially very precise digitizing of various island features. Using the other background colors, other than blue, gives a washed out effect. Not very handy for digitizing work.

My biggest challenge when working on an island mapping project is determining the shoreline - where the water meets the mostly dry land. Using the Global Mapper's Blend Mode and changing background colors is a great way to meet this challenge.

Enjoy!

Labels: Blend Option, Color Burn, Difference, digitizing, Global Mapper, Landsat ETM+

Posted by Mr Minton at 1/25/2008 03:50:00 PM | Permalink | Comments | links to this post

Nisos Skiathos - LIIM with a Black Sea (1:90,000)

Let's begin with the LIIM of Nisos Skiathos. There are times I would like to switch off a range of colors or, for that matter, switch off any colors I wish to. I asked Mike at Global Mapper if a modification like this would be possible. He said that it seemed to be a fairly simple process and he would modify Global Mapper v9.0 to allow this color by color control.

<

How To Create Transparent Seas

The process to switch a color or multiple colors off is simple. The image I used is a GeoTIFF 8-bit. Within the Overlay Control Center select the image and open it with Options. Select the Transparent feature and you will be given a palette of colors. This image contains 255 colors using the GeoTIFF 8-bit image option. Either use the shift-key to select a range of colors or the control-key and pick and choose any colors you want. I selected all of the colors that defined the black sea. Switching them off gave me the image below.

Nisos Skiathos GeoTIFF 8-Bit Transparent Sea (1:90,000)

Pretty slick, huh? The process to switch off the black sea and make it transparent took about 30-minutes to complete. I really like this feature. It allows for some pretty creative imagery analysis. For example, the burned area on Nisos Skiathos could be easy to isolate and study in greater detail.

Global Mapper's way of doing business - 1) Ask for a feature. 2) If it can be done, Mike will add the feature. If not, Mike will tell you straight up. 3) And the cost for the feature update - $0.

Enjoy!

Labels: GeoTIFF, Global Mapper, LIIM, Transparency Tool

Posted by Mr Minton at 1/18/2008 11:34:00 PM | Permalink | Comments | links to this post

Nisos Skiathos - LIIM from N-34-35_2000 (1:70,000)

Nisos Skiathos is the westernmost island of the Sporades. It is reported to be heavily forested with pine trees. However the ugly red splotch in the center of the LIIM is a burn signature. When a forest fire occurs on a small island, it puts all of the inhabitants at risk. This fire was restricted to the mountainous interior. It would have occured over 7+ years ago and I am confident organic ground cover has returned to the area. According to a Nisos Skiathos web site, the island is heavily populated with tourists during the summer months. They visit the old fortress at Kastro (NE), long stretches of sandy beaches and enjoy a festive nightlife in Skiathos town.

My perfect visit to this island would be off-season. I would spend my time exploring and visiting with the local folks. In the evening I would walk in the town looking at the shops and selecting a taverna to dine in. Then I would retire to my room overlooking the sea. I would relax on my balcony with a good book, a glass of 20-year old port wine, a Cuban cigar and soft music in the background. I would fall asleep at 1:00 AM, wake up at 5:30 AM and start all over again. Wow! Now that is living on the edge.

Nisos Skiathos - EVS Precision Marplot Map (1:70,000)

The map was created in approximately 4-hours. It was a fairly straight forward island mapping project. Nothing out of the ordinary. I am working on color schemes for my various map layers. The colors are still being explored. I have been using Marplot's text feature. One has the option of using five different fonts. You control the size of the text by selecting and dragging it until you are satisfied with the size. I have used Time New Roman font for this island mapping project.

Enjoy!

Labels: EVS Precision, Global Mapper, Greece, Landsat ETM+, LIIM, Marplot

Posted by Mr Minton at 1/16/2008 05:54:00 AM | Permalink | Comments | links to this post

Nisos Skopelos - LIIM From N-34-35_2000 (1:100,000)

Nisos Skopelos is a fertile and densely-wooded island. Adjacent to the town of Skopelos is a harbor that handles the ferry boat traffic - tourists and goods from the mainland. There are a few smaller harbors that provide safe haven for the sailing crowd, especially the harbor at Ormos Glossa.

Nisos Skopelos - EVS Precision Map with Roads (1:100,000)

This island project took about 6-hours to complete. The shoreline was completed quickly. The feature that took the greatest amount of time was the island's intricate road network. I used a map found on Skopelos Web Site. I georeferenced the map and placed it on top of my base image. I then carefully digitized the road network, paying special attention to the size classification of the roads. I imported the completed files into Marplot where I finished this map. The names and locations of various island features were taken from Sailing Directions Pub 132, Section 16-10.

I have secured approval to use the road network on this map from the copyright owner, Yiannis Chatzitrakosas. Landsat ETM+ does a poor job of showing roads and trails, where as Yiannis' map shows all class of roads on the island..

Enjoy!

Labels: EVS Precision, Global Mapper, Greece, Landsat ETM+, Marplot, Sailing Directions, Sporades

Posted by Mr Minton at 1/15/2008 08:20:00 PM | Permalink | Comments | links to this post

Drag, Drop and Load Nisos Pelagos LIIM in 5-Seconds

To continue my discussion of yesterday concerning my choice to use Global Mapper as my digitizing platform. $299 is what Global Mapper costs today. That allows you to download and activate your software. The key you get needs to be saved as you will use it again when you purchase the updated packages. I have gone through 3 updates. Some users are still using early versions of the software. It depends on what features you require. The major updates happen typically on an annual basis.

My first purchase was GM v6.00. It cost me $199. I had purchased Manifold mapping software for $199, previously. The learning curve for Manifold was too steep for me. I am not bad-mouthing Manifold. It just didn't work for me. The same goes for Quantum GIS and Open Jump. Tried them, but they didn't do what I wanted to do. I even had an educator's copy of ARC GIS, but, again, the learning curve was too steep for me. Again, I'm not anti any of these mapping packages, just they didn't work for me.

The first time I used Global Mapper v6.0, I was sold on it. I had been viewing Landsat ETM+ mosaics in MrSID format using my browser and Lizard Tech software. I knew that I wanted to use Landsat ETM+ images to make maps with but I work with an extremely limited budget. I came across Global Mapper, downloaded their demo version, opened it and from the file menu I selected a 250MB Landsat ETM+ image of the African Sahara. Within 5-seconds it was loaded. I zoomed in until I viewed distinct features at a scale of 1:62,500. I was able to move about the image effortlessly. I noticed the "pencil" on the menu bar and selected it. Within a few seconds I was digitizing a feature. All of this withou reading any instructions! Needless to say, I was hooked.

That was 3-years ago and I continue using Global Mapper with no regrets. I am able to easily construct my maps using only this software. If I have a question or a problem, I merely email Mike. Global Mapper has unparelled customer support. Mike is an email away. He responds promptly to your questions and recommendations. If he is able to easily add a feature or tool, he does it and makes the updated copy available for all users FREE.

The $199 + $99 + $99 is the best mapping investment I have ever made. If you want to make maps like I do using Landsat ETM+ or DigitalGlobe he-res imagery, Global Mapper is your ticket.

Enjoy!

Labels: Global Mapper

Posted by Mr Minton at 1/08/2008 06:14:00 AM | Permalink | Comments | links to this post

Step 1 - Drag, Drop and Load LIIM (5-Seconds)

Let's keep this simple. First I locate the georectified island image I want to work with. This is Nisos Pelageos LIIM. I merely drag the icon, drop it onto Global Mapper (GM) and it loads. The entire step took 5-seconds.

Step 2 - Before Applying Anti-Alias (8-Seconds)

Step 2 can happen when the image is at full view. I zoomed in to show you why I use the Anti-Alias effect (smooths pixels). The above image shows the square pixels. In my opinion they are clumsy to work with. I will smooth them out with the Anti-Alias effect. I select the image through a menu item.

Step 3 - After Applying Anti-Alias (2-Seconds)

Once the image is selected and the Anti-Alias effect is switched on, I end up with smoothed pixels. They are much easier to work with for the purposes of my maps. Steps 2 and 3 took 10-seconds.

Step 4 - Zoom to 1:12,500 to Begin Digitizing (10-Seconds)

I like to work at 1:12,500 scale when I digitize from LIIMs. Depending on my expectations, the clarity of the image and other factors, I will sometimes work at larger scales to obtain my EVS precision mapping. Zooming takes 10-seconds. Most of that time is spend zooming in on the correct portion of the image.

Step 5 - Select Create New Line (5-Seconds)

In Step 5 I select the digitizing option and right click to select the specific function. I work primarily with polylines, so I select Create New Line. That takes 5-seconds.

Step 6 - Digitized Line (Polyline)

Now comes the fun part, digitizing the shoreline or whatever layer of information you wish to work on. Digitizing with GM is tracing a consistently defined shoreline. That's the tricky part. That part takes lots of practice. But from load to digitizing - that only takes 30-seconds with GM and that really makes me happy.

Enjoy!

Labels: digitizing, Global Mapper, LIIM, polyline

Posted by Mr Minton at 1/07/2008 07:02:00 AM | Permalink | Comments | links to this post

59 Greek and Turkish Island LIIMs

Like I said in my previous post, I wanted to complete the primary Landsat Island Image Mosaics (LIIM) for the Greek and Turkish islands located in the Aegean Sea before I returned to school. Well, I'm done. The largest LIIM, at 100MBs, is the 3-sections (West, Central and East) covering Crete. All of the large Greek and Turkish islands located in the Aegean Sea are now covered by a LIIM. What does this mean to you?

Not much, if you have your own collection of Landsat ETM+ mosaics. Or, you are a user of Google Earth or World Wind and you say, "I have all of the imagery. What do I need with LIIMs?

I make maps using Landsat ETM+ imagery as my base image. Using Global Mapper's digitizing tools, I am able to create complex vector layers of information. I've used the digitizing tools found in Google Earth. They are good, but not great. And if you make a series of polygons, you must create a unique record for each polygon. Not practical when you create hundreds of polygons on a single map.

I need some of you to try the LIIMs out. Give me the name of a Greek or Turkish island and I'll send you a copy of the appropriate LIIM. Let me know what you think? Is it useful?

Enjoy!

Labels: Global Mapper, Greece, Landsat ETM+, LIIM, Turkey

Posted by Mr Minton at 12/29/2007 08:55:00 PM | Permalink | Comments | links to this post