EVS-Islands

Cook Islands - Landsat ETM+ Coverage

I have been very busy digitizing islands. In fact, I have just completed digitizing over 3,000 large and small islands making up the western portion of the Solomon Islands. I'm currently digitizing island shorelines in Papua New Guinea. All of this work is being done at EVS precision - using Landsat ETM+ base imagery and digitizing shorelines at a scale between 1:25,000 up to 1:50,000. Some of you have reminded me that because Landsat ETM+ is typically 14.5-meter resolution that digitizing at the scale I work at is overkill. After spending close to 3-years working with 14.5-meter resolution imagery, the maps I am able to produce work quite well. I wouldn't want to sail into a lagoon using only ETM+ imagery, but I could do excellent advance planning and rough navigation using maps derived from this imagery. I know my maps are often far superior in shoreline validity when compared to some of the very old nautical charts still in use today.

Anyway, this is supposed to be about green dots on a deep black sea. In between work on the Solomons and Papua New Guinea, I completed EVS precision mapping of the Cook Islands. The first image in this post struck me. It took seven Landsat ETM+ mosaics to cover the Cook Islands. If you study the above image at full size, almost all of these very small islands are impossible to see. Yet, they enable countries, like New Zealand, to claims (EEZ) enormous chunks of liquid real estate. These very small islands play a significant role in the distribution of world resources. Interesting.

Cook Islands - Marplot Map with 25-km Ocean Masks

The Marplot map of the Cook Islands shows their distribution more clearly. They are scattered about within a peculiarly shaped border, that is if one finds rectangles peculiar. Actually, their EEZs would spill outside of their international border. I'm not sure if the border serves to limit their 200-NM EEZs. If that is the case, too bad for New Zealand and the Cook islanders.

Penrhyn Atoll CW - Landsat S-04-05_2000 Image (1:125,000)

Just to confirm that there are islands located in this broad expanse of black ocean, here is one of them, Penrhyn Atoll. It has a classic atoll shape with a lagoon full of near surface coral heads. I have not researched Penrhyn as I was in a digitizing mode when I worked on it, not in an investigative one.

Penrhyn Atoll CW - EVS Precison Island Polygon Map (1:125,000)

This is my EVS precision map of Penrhyn Atoll. It is a solid shoreline depiction. My customary mapping effort of an atoll would include a number of additional layers of information - reefs, beaches, vegetation. As my client requires only shorelines, I digitizied and mapped the island's above-water shoreline and portion of it's awash reef. Again, it is a solid shoreline mapping effort and one that I will revisit to complete the other layers of information I would typically map.

I am still here, just not able to post as often as I would like. When I finish my paying mapping project (Whoopee!), I will share many, many, many more islands. Until then...

Enjoy!

Labels: Cook Islands, digitize, EVS Precision, Landsat ETM+, Papua New Guinea, Solomon Islands

Posted by Mr Minton at 4/30/2008 08:22:00 AM | Permalink | Comments | links to this post

View Larger Map

Banaba Island

Set These People Free! They got shoved off of their island back around the turn of last century, because they wanted the British, New Zealand and Australian interests to stop extracting phosphate, derived from bird guano, from their island. They got the old colonial wham-doozie! A contract that they didn't understand, a deal that gave away their island resource for next to nothing, a forced evacuation and after their island had been brutally plundered and not repaired, they were allowed to return. Just recently the courts awarded them $10 million for the past injustices - a mere pitance for all that they have been subjected to. There are a couple of web sites that tell their story: Abara Banaba, Wikipedia article and streaming video of a fly over of the island by Greenpeace.

The map was digitized within Google Earth using DigitalGlobe imagery and ultimately constructed in Marplot. I spent the last six to eight hours working on this relatively small island, but I learned alot while working on it. It is my first island I attempted to digitize all visible buildings. I think I did an excellent job.

What got me started on this particular island was the British Hydrographic Office Catalog of Nautical Charts. They publish a 1:50,000 scale chart (HO 979) of the island proper. This seems to me to be too large scaled to be of real use. In addition, they have a chart showing harbor details at 1:12,000 scale. I personally like my 1:3,125 view of the harbor. Also their chart was originally constructed in 1884 and updated in 1964. My data is from DigitalGlobe imagery gathered in the last couple of years. However, their charts are designed to be used by boaters, mine are not. I make maps, very nice maps, but just maps.

I couldn't leave well enough alone. I added a fourth image, a Marplot map at 1:20,000. The colors have been changed, a text box with appropriate credits is added, a nifty North Arrow and contours at 5-m intervals. I like the new look. One can soften colors too much. The colors used on this map are a bit bolder to draw attention to the features they depict.

Enjoy!

Labels: British Hydrographic Office, DigitalGlobe, digitize, Google Earth, nautical charts

Posted by Mr Minton at 3/27/2008 02:40:00 PM | Permalink | Comments | links to this post

Easter Island - EEVS Map (1:100,000)

This is a continuation of my previous post. EEVS quality mapping requires lots of vectors. As the title states, at this preliminary stage, 12,615 vectors were digitized by me to create this shoreline. I worked in Google Earth using the path tool. The first pass was relatively fast taking about 6-hours. The final pass, the fine tune, took another 3-hours. I will have to work on this shoreline in Global Mapper to finish it. Two parts of the island, the north and western edges will be digitized using Landsat as they are not included in the Google Earth map. I have loads of work to do on this map digitizing layers of information.

My point is that DG imagery is great, but to execute a quality shoreline, one must do lots of digitizing.

Enjoy!

Labels: DigitalGlobe, digitize, EEVS, Landsat, vectors

Posted by Mr Minton at 8/03/2007 08:16:00 PM | Permalink | Comments | links to this post

I receive numerous requests for special project maps. Most of them I do, a very few I don't. Lately, representatives from non-profit groups have solicited my map-making talents to construct maps and secure imagery for their special projects. Their budgets are $0.00 for mapping. If the group's work furthers the quality of life of both human and non-human (flora and fauna) inhabitants of these fragile places, I try to help. They begin by asking if I use ArcGIS. I tell them I too operate on a $0.00 budget and it is too expensive. They then ask "how I do what I do when I do what I do" in making my maps. So I explain my map making processes.

When I first began making maps, I used Landsat ETM+ mosaics exclusively. They enabled me to create detailed shorelines, where none had existed before. I made lots of maps using this database of imagery. Then came Google Earth and then came DigitalGlobe hi-res imagery. Many of my current projects use this imagery for a base. It is how I use it that this post deals with.

(The following is the essence of an e-mail I sent to one of my non-profit contacts. It explains "how I do what I do when I do what I do" in making maps using DigitalGlobe hi-res imagery in Google Earth.)

Iwo To - DigitalGlobe Image From Google Earth Detail Suribachiyama (1-12,500)

Capturing and georeferencing DG imagery can be done. Depending on the level of detail required, the number of images captured and georeferenced can be extensive. For example, a relatively small island I recently digitized required over 30 DG images taken from GE. One must be patient and practiced at creating mosaics from these separate images. I ensure all images are at the same scale on GE, systematically select and save them to my desktop,

Creating a Photo Mosaic From Shuttle Images using ImageForge

and then create a mosaic of images in a draw program (ImageForge).

DG Image Georeferencing in Global Mapper

I take these mosaics and georeference them using my preliminary mapping program (Global Mapper), where I do the bulk of my digitizing.

Digitizing from Landsat ETM+ Image using Global Mapper

As I complete digitizing areas of interest from these base images, I import the vector files into my primary mapping program (Marplot),

Making Maps using Marplot

where I create my maps.

******************************

Another process, much simpler, but still challenging,

Digitizing using Google Earth tools

is to digitize island shorelines and information layers using GE's path and polygon capabilities. Both of these digitizing tools are extremely powerful and flexible for the type of mapping I require. After digitizing a number of layers of information, I process the KML file into a simple ASCII vector file and import them into my preliminary and primary mapping programs where I create maps from these GE-derived vectors.

******************************

Both methods have taken me over two years to master, but the end-product is cool!

Banaba Island - Marplot Map with Contours (1-20,000)

I am an accomplished map-maker when it comes to using DG/GE imagery. I currently work with two university-affiliated non-profit organizations supplying maps and images for their island projects. My maps have been viewed by over 25,000 visitors this year alone. Most are arm-chair travelers. However, a substantial group represents a "Who's Who" of the GIS community and the business community using GIS in their work.

My map-making processes can be taught to the right students. Given time (months), genuine enthusiasm (you have to love the map-making process and the final product), an aptitude for monotonous work (digitizing and tweaking the project) and the ability to constantly improve your map-making skills, I could teach someone, with these attributes, how to make maps of islands. Or, I could make your island maps myself. Whatever.

(And that is what I said about me and my maps. Interesting, huh?)

Enjoy!

Labels: DigitalGlobe, digitize, Global Mapper, ImageForge, Landsat, Marplot, vectors

Posted by Mr Minton at 6/30/2007 10:24:00 AM | Permalink | Comments | links to this post

Loading Landsat Into Global Mapper

Yes, I am cheap. If I can get something for free, that is my best price. It pains me to spend money, yet, I spent over $300 on my versions of Global Mapper. Now why would a tightwad like me spend money on something he could get free. (I am assuming that some of the open-source GIS packages could accomodate Landsat imagery and digitizing.) Many months ago, I downloaded the free trial version of Global Mapper and figured I give it a try. I was skeptical. I had my Landsat (MrSid format) and within seconds I had a 250MB file loaded and viewing it. It was cool! I was so impressed, I immediately got myself a working copy of the software and have been extemely pleased ever since.

The above slideshow details how one would load six Landsat images (about 1GB) in seconds. Within in one minute, you could be digitizing a shoreline of a target island. Global Mapper loads Landsat lightening fast. I know there are other packages that claim to be fast, but when I can load the image and begin digitizing within a minute, I'll spend my money with that company.

The pictures walk you through the steps to follow in order to load Landsat into Global Mapper. I was a bit careless when I first amassed my original collection of Landsat images and deleted all of the supporting files that allow for auto-georectifying. My extra steps involve, selecting the appropriate projection (UTM zone 28 for these images) and Datum (WGS-84 for Landsat ETM+).

Another plus is the excellent support a licensed user receives from Mike. Mike is Global Mapper and he personally makes sure everything works the way it is supposed to. Great service. Slick product, worth every cent!

Enjoy!

Labels: digitize, Global Mapper, Landsat

Posted by Mr Minton at 6/15/2007 03:11:00 PM | Permalink | Comments | links to this post

Dar es Salaam - Left Panel (1:12,500) / Right Panel (1:6,250)

I create Enhanced Vector Shorelines (EVS) from images at scales between 1:12,500 to 1:6,250. A solid representation of the shoreline can be determined. There are features that one cannot distinguish, but the shoreline is not one of those. However, if one wanted to digitize a shoreline with a very high degree of confidence, hi-res imagery is needed.

Dar es Salaam - Digital Globe Image From Google Earth (1:12,500)

Using the above imagery, shoreline questions are quickly resolved. Where Landsat ETM+ (first image) is free for the downloading, Digital Globe Hi-Res imagery is partially free. If you want to make maps with their Google sponsered images, you can as long as your work is not-for-profit. If you want to earn a buck, you will need to make arrangements with DG. If you require unique imagery, the cost is between $400 up to $1,500. Them is some big bucks for us little folks.

I understand their need to control their images. DG had to pay lots of up-front money before they could begin marketing their products. And their traditional customer base of government, military and big businesses, all with deep pockets, find their prices reasonable. But, how about us little folks?

I have found that the folks at DG are gracious and will work hard to find a way to accomodate your request. And their supply of hi-res images to Google Earth is unprecidented. But, again, wouldn't it be nice to make a buck off of a map produced from their Google Earth sponsered images? Yes, it would!

view Dar Es Salaam TZ on Google Maps

Enjoy!

Labels: Digital Globe, digitize, EVS, Landsat, mapping

Posted by Mr Minton at 4/02/2007 06:16:00 AM | Permalink | Comments | links to this post

I am a long time user of both WVS (World Vector Shorelines) and GSHHS (Global Self-consistent, Hierarchical, High-resolution Shoreline) vector map files. They are both drawn at a scale of 1:250,000. Beginning with WVS map files over 4-years ago, I quickly ran into frustrations as I attempted to convert vector lines into vector polygons. WVS has many inherent issues that make this transformation difficult. I learned of GSHHS and set about to replace my WVS map files. However, GSHHS requires a conversion into ARC Ungenerate format (the format I work with) and is Pacific centered. I managed to have the file converted and transformed into Greenwich centered and I started working with GSHHS map files. I appreciated the fact that I had the "best" free complete worldwide vector map coverage. But something was missing. Using Space Shuttle imagery, I found that GSHHS was too coarse and Shuttle imagery had to be georectified.

I then discovered Landsat ETM+2000 mosaics. They were free. One needed sufficient time and modem speed and this excellent base imagery could be yours. I spent one summer two years ago and I now have all of the coverage for world shorelines. I produced my first vector map from Landsat ETM+ and compared it to the WVS/GSHHS shorelines. The difference is dramatic!

After that mapping experience, I now use GSHHS produced maps only for broad area coverage (1:500,000 and above). I've seen the promised land and I can't settle for anything less!

My quest is to produce an Enhanced Vector Shoreline (EVS) World Map using a collaborative approach consisting of a trained team of 100+ map makers. They will be trained to digitize

shorelines following a rigorous protocol, to include all features unique to this highly dynamic environment. Each individual will be responsible for either a portion, single or multiple ETM+ mosaic(s). They will digitize all assigned shorelines found on their Landsat mosaic, using a carefully developed criteria and procedure. Their finished vector map files will be evaluated and corrected by a quality assurance team of professional geographers (volunteers). Finally, the finished product (1:100,00 scale and better) will be compiled and made available to all potential users at no cost.

The construction of the EVS Worldwide map will be done as a non-profit project. The cost of development, implementation and final product support will be covered by donations of cash, software and computer hardware from both public and private organizations and/or grants that will enable this team to: 1) Introduce the EVS Worldwide Mapping Project to the target group of potential participants - highly motivated high school and college students from the America's, Africa, Asia, Europe, Australia/Oceania. 2) Select and train the team of digitizers/mapmakers. 3) Implement the communication system to move Landsat mosaic images, transfer digitized pre-processed vector map files, provide for daily contact and easily facilitate the processing of a completed Enhanced Vector Shoreline map file. 4) Take all of the processed vector map files and combine them into a single world map product.

Ideally, this project will have worldwide participation. It will be a mapping effort by a worldwide community of dedicated mappers. Each participant, upon completion of their assigned portion of the project, will receive a laptop computer loaded with GIS software as tangible compensation for their efforts. The same one they used in compiling their respective portion of the project. More importantly, they will have received consistent, quality training and practical experience in the "gentle" art of map making. From this group will come the next generation of map makers, trained and experienced.

This project will take from one to two years to complete the world shoreline at EVS precision. As the completed EVS World Map is broadly disseminated, new layers of information will be required. This is where the project is transformed into a for-profit enterprise, as these desired layers will be completed at a fair-market value. And what team better to accomplish this next phase than the original members of the EVS mapping team (highly motivated, trained and experienced map makers). The creation and integration of additional layers of useful information will engage this team in a highly profitable enterprise for years to come.

EVS World Map will become the default worldwide map for years to come.

Mine is the vision. Now, I need the team and the funding. Any takers?

P.S. - Hi-Res Imagery provides shoreline coverage for much of the world. If this imagery were made available, the digitized shoreline precision could be tremendously enhanced. Would a company such as Digital Globe make their imagery available for a worldwide shoreline mapping project? Perhaps. To be the company that helps to fund and sponser this effort is a public relations coup.

Labels: Digital Globe, digitize, EVS, GSHHS, Landsat, WVS

Posted by Mr Minton at 3/29/2007 06:50:00 AM | Permalink

Pulau Romang Island Group

I've been working on this group of islands for the past few weeks. All of the layers of information are digitized. This week I will bring the digitized files into Marplot and construct my map. After the map is complete, I will create contours. Finally, I will publish the completed images.

Improved Rapa Island Shoreline and Contours

This project is also in the final stages. I discovered Digital Globe hi-res imagery on Google Earth covering most of the island. The improved shoreline is complete. I will create as many additional layers of information as the imagery will allow. The western portion of the island is cloud covered. DG does have a cloud-free image. Maybe they will let me use it? Unfortunately the SRTM data covering the island has large voids that I will have to extrapelate the course of the contours. I will need to find a reasonable topo of the island (fat chance!) or do my best guess-timation of the missing contours. It should be a challenge.

Cabrits NP Dominica Island

This is part of a viewer's senior project. You all know that I do work for free. If it is non-commercial, within my abilities and the time-frame is mutually agreeable, I'll create an EVS precision project for you to use. It turned out this area has Digital Globe imagery to work from. Consequently, the land use layers were detailed and complex. The SRTM data had a void that I had to guess-timate the contours. For the purposes of this student's project. the time constraints and the fact that I was working in uncharted areas of expertise, the guess-timate method was sufficent. I worked on this project off and on for over two weeks and am pleased with my efforts.

Other projects being worked on are Lindesfarne Island, UK and The Three Maria's located off the western coast of Mexico.

So many projects and not enough time.

Enjoy!

Labels: Digital Globe, digitize, EVS, Global Mapper, Google Earth, map, Marplot, SRTM

Posted by Mr Minton at 3/19/2007 06:06:00 AM | Permalink | Comments | links to this post

Making a Map in Google Earth

This is a very popular series of images taken from an earlier post. Making a map from Google Earth imagery, more precisely, from Digital Globe (DG) imagery found in Google Earth is detailed in the above image collection. If you are fortunate enough to have your specific area of interest covered in DG's hi-res imagery, you can construct an exquisite vector map using it while in Google Earth Plus. GE Plus is the $20 per year version of Google's popular earth-viewing software. Within the software is the capability to construct rudimentary maps. I use GE Plus to construct highly detailed shorelines and land use areas of some of my project islands. I call these shorelines HRVS or Hi-Res Vector Shorelines.

The "How To Digitize" is displayed in the set of images that accompany this post. The process is simple and the vectors constructed can be directly imported into most popular mapping packages. Using a free translater tool, GE Path, KML files can be imported into MS Exel where one can easily create ARC Ungenerate format vector mapping files. These vector files can be imported into many other less well-known mapping packages, including my personal favorite, Marplot.

Enjoy!

Labels: Digital Globe, digitize, GE Path, Google Earth Plus, hi-res imagery, HRVS, Marplot, vectors

Posted by Mr Minton at 3/14/2007 06:17:00 AM | Permalink | Comments | links to this post

Comparison of Four Different World Vector Shorelines

If you look at most commercial digital atlases, their data is based on Operational Navigation Chart (ONC) data, which was originally compiled and maintained so that pilots could use these maps as reference tools when viewing features from 20,000 feet. They worked well for their intended purpose and were reasonably maintained. They were largely fashioned from pre-satellite data, much of it derived from aerial photography dating from WW-II through pre-Vietnam. Any cartographer worth their mapping "salt" will tell you that much of the data is, at best, only moderately accurate. ONC shorelines are close to actual shorelines, but not very close. The ONC shorelines were never intended to mirror the actual shoreline. I mean the scale is 16-miles to the inch!

So from this data source a product called Digital Chart of the World (DCW) was produced. Every atlas company producing small scale mapping uses some or all of the DCW data. Since my area of focus is global shorelines, I can state with certainty that if DCW shorelines are used in a map product, those shorelines are only moderately accurate. But for many map users, moderately accurate works. My Michelin maps got me from city to city and allowed me to navigate with a solid degree of certainty.

World Vector Shorelines, at a scale of 1:250,000 (4-miles to the inch), were fashioned from Tactical Pilotage Charts and other similar sources. Their shorelines are more accurate than DCW/ONC shorelines. However, they also more often miss the shoreline than track it.

Landsat ETM+ 2000 Coverage

Now we get into the realm of space-based mapping. With a virtually cloud-free image of earth, Landsat gives us a georectified imagery base from which extremely precise shorelines can be extracted. And it was done! The Prototype Global Shoreline, using a carefully researched, crafted and tested digitizing algorithm created a global shoreline that can be used at between 1:125,000 to 1:62,500 scales. If DCW/ONC shorelines are moderately accurate and World Vector Shorelines are extremely accurate, Prototype Global Shorelines track the shoreline with a high degree of reliability. That is until one zooms in and studies the PGS vectors as they relate to the Landsat image from which they were derived.

EVS and PGS Vectors

Upon closer inspection, they do not track the shoreline very often. They are typically anywhere from 15-meters to 200-meters off-center. Their vectors have a habit of "stuttering" unneccessarily as can be seen in the above image. They also do not account for large sections of shoreline that is water innundated, per NIMA's request.

EVS Would Digitize the Water Inundated Areas

EVS vs PGS Precision

Finally I get to my product, Enhanced Vector Shorelines (EVS). All of my shorelines are done by hand. The vector plotting errors inherent with this methodology are minimal compared to PGS errors. EVS provides the most accuracte shorelines extracted from Landsat ETM+ 2000 mosaics. Unfortunately, that only includes the coast of Morocco, Taiwain, Madagascar, Baja California, Caspian Sea and many islands scattered throughout the world.

Now to repeat the question I posed at the beginning of this post, "Who cares?" Should the world shorelines be mapped at EVS precision? Is the PGS, which is pretty good, sufficient for most projects? Is pretty good, good enough?

I think that a world shoreline at EVS precision would be extremely useful. I believe, that properly constructed, it would become the base mapping data for military, government and private sector projects for years to come.

I know I have a large number of GIS savy readers. What do you think? Should the world be mapped at EVS precision? And if so, why? Feedback would be appreciated.

Enjoy!

Labels: DCW, digitize, EVS, Global Shorelines, Landsat, ONC, PGS, SRTM, WVS

Posted by Mr Minton at 3/11/2007 04:50:00 PM | Permalink | Comments | links to this post