Showing posts with label EVS Precision. Show all posts
Showing posts with label EVS Precision. Show all posts

Saturday, February 23, 2013

Samana Cay BF - Columbus' First New World Landfall?

  Samana Cay - Landsat ETM+ Image N-18-20_2000 (1-85,000) 
Samana Cay - Landsat ETM+ Image N-18-20_2000(1:85,000)
 
Samana Cay - EVS Precision Map (1-85,000) 
Samana Cay - EVS Precision Map (1-85,000)
 
My interest in Samana Cay was the result of a serendipitous moment.  A few evenings ago while editing my Islands of the World point file, I became curious about the Turks and Caicos Islands.  Using my GSHHS World Shoreline map, I located the Turks and Caicos Islands.  Not an area I have done much mapping in, but interesting.  To the northwest was a small island off by itself, Samana Cay.  Nothing particularly outstanding, just a nice little island facing the Atlantic Ocean.  Curious soul that I am, I checked out the Wikipedia article and Wow!  Some scholars think this might be the site of Christopher Columbus' first landfall in the New World.  Pretty cool.

I identified the Landsat ETM+ mosaic, loaded it into Global Mapper and began mapping.  The completed map is nice.  The Landsat image is pretty cloudy.  More research and my next Wow!  Samana Cay is the largest uninhabited island in the Bahamas.  An uninhabited island close to home (USA).  How cool.

All of you Florida readers hunting for your Crusoe Getaway, Samana Cay could be your island.  People from Acklins Island visit periodically to collect cascarilla bark.  Other than the occasional Acklins Island visitors, you could be all alone contemplating whatever it is you want to contemplate.

Enjoy!

Monday, January 17, 2011

Marmara Island TR - Modifying SRTM v4 TIF with EVS Precision Coastal Vector File

Turkey - SRTM Vector Modified

Turkey - SRTM with EVS Vector Modifications

The map of Turkey on the left is a portion of a 600-MB World Map created by Tom Patterson. His excellent and informative website, Shaded Relief, contains a wide variety of shaded relief maps. He explains how you could create your own shaded relief maps. I have been content to download his finished maps and use them in my classroom. The students love working with them.

I have been a long time user of SRTM data. Using tools within Global Mapper, I was able to generate interesting 3D views of islands. Last week I came across SRTM v4 data at CGIAR Consortium for Spatial Information (CGIAR-CSI), which I call Cigar (See-gar) for short. I downloaded a number of SRTM TIF images covering Turkey, where I am plotting Roman era towns and cities. Using the Shaded Relief Natural Earth 1 world map I was able to plot at scales of 1:1500000 to 1:1000000. When I attempted to work closer the map became a screen full of pixels. What to do?


Marmara Island - SRTM EVS Modifications Before and After (1-25,000)

Marmara Island - SRTM EVS Modifications Before and After (1:25,000)

The SRTM v4 data offered me some intriguing possibilities. First, I was able to zoom into areas at scales between 1:500,000 down to 1:50,000. At 1:50,000 I had to contend with pixels. The vertical side of a pixel in the part of the world I am working in is 90 meters, the horizontal side is 70 meters. Clunky looking when working at 1:50,000. It was then that I had my "ah-ha" moment. I loaded Landsat imagery on top of the SRTM imagery. I then digitized shorelines using the Landsat imagery (section 1). I switched off the Landsat imagery and my EVS precision shoreline cut through SRTM v4 pixels (section 2) and allowed me to determine the shoreline on the SRTM image. The SRTM modified shoreline is now useful to scales as fine as 1:25,000 (section 4).

I know! A 14.5 meter pixel defining a 90-meter pixels leads to potential problems. However, for my purposes, plotting Roman era towns and cities, these SRTMs modified with EVS precision shorelines work just fine.


Marmara Island Vicinity - SRTM with EVS Modifications Before and After (1-250,000)

Marmara Island Vicinity - SRTM with EVS Modifications Before and After (1-250,000)

And at 1:250,000, they look great!

A word about my custom hypsometric tints. The colors I initially took from the Shaded Relief website. But I have since tweaked them a number of times. The current version, certainly not my last, looks great for this part of the world.

I am slowly, but surely working my way around the shoreline of the Sea of Marmara, a place I spent time as a young man. I do hope this was both informative and interesting.

Enjoy!

Wednesday, March 17, 2010

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

King George Islands FP - Locator Map Wagner IV World

Marutea Atoll Nord FP


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

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 Modified Image (1-150,000)

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)

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!

Sunday, February 28, 2010

Thoughts - Which Color Scheme Works Best for EVS Maps?

King George Islands FP - Locator Map Wagner IV World

King George Islands FP


King George Islands FP - Landsat ETM Image S-06-10 (1-175,000)

King George Islands FP - Landsat ETM S-06-10_2000 Image (1:175,000)


King George Islands FP - EVS Precision Map (1-175000)

King George Islands FP - EVS Precision Map (1:175000)


Takapoto Atoll FP - EVS Precision Map (1-80,000)

Takapoto Atoll FP - EVS Precision Map (1:80,000)

I spent today digitizing the King George Islands located in the Tuamotu Islands FP. The top atoll, Takapoto, was just completed using my new NIMA color scheme. Not only am I limiting layers to EVS island projects to island polygon, reef shallow, lagoon and island water feature, but I've changed my color scheme to match NIMA's nautical charts. My current color scheme is as follows:

island polygon is R-245 G-245 B245

reef shallow polygon is R-205 G-225 B-235

lagoon is R-225 G-250 B-255.


Takaroa Atoll FP - EVS Precision Map (1-80,000)

Takaroa Atoll FP - EVS Precision Map (1:80,000)

Takaroa Atoll, completed a few months ago, contains my old color scheme:

island polygon is R-240 G-232 B-217

reef awash is R-208 G-234 B-224

reef shallow is R-153 G-214 B-236

lagoon is R-090 G-169 B-211

In both projects the vegetation layer R-157 G-179 B-151 and the deep ocean layer R-165 G-207 B-231 are unchanged.

For visual appeal, I like the old style. The NIMA nautical chart style gives a cleaner, crisper look. What do you think?

Enjoy!

Friday, November 27, 2009

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

Olimarao Atoll - Locator Map

Olimarao Atoll Locator Map

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


Olimarao Atoll - Vicinity Map from Google Maps

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


Olimarao Atoll - Vicinity Map from Yahoo Local Maps

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


Olimarao Atoll - Vicinity Map from Bing Maps

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


Olimarao Atoll - Vicinity Map from OpenStreetMap

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

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


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

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

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


Elato and Lomolior Atolls - DG Preview Image from GE

Elato and Lomolior Atolls - DG Preview Image from GE


Elato and Lomolior Atolls - DG Preview Image from GE Cropped

Elato and Lomolior Atolls - DG Preview Image from GE Cropped

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


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

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

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

Enjoy!

Sunday, July 19, 2009

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


Motu Iti FP - EEVS Precision Map (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!

Tuesday, June 30, 2009

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

Robinson Crusoe Island - Wagner IV World

Robinson Crusoe Island CL


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

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


Robinson Crusoe Island - DigitalGlobe Image from Google Earth

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


Robinson Crusoe Island - EVS Precision Map (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.


Rob-cru

Robinson Crusoe Island - Wikimedia Commons


Mapa

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.


5410

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!

Thursday, May 21, 2009

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

Arutua Atoll FP - EVS Precision Map From Landsat S-06-15_2000 (1-170,000)

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


Atoll (1-75,000)

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

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

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

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


GM Image Capture

Global Mapper Image Capture

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

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

Enjoy!

Sunday, May 10, 2009

Thoughts - Bennet Island and Mi Vida Loca

Bennet Island - Landsat Image N-54-75_2000 - A Partial View (1-44260)

Bennet Island - Landsat Image N-54-75_2000 - A Partial View (1:44,260)


Bennet Island - EVS Precision Map - A Partial View (1-44260)

Bennet Island - EVS Precision Map - A Partial View (1:44,260)

It has been one very busy school year. As most of your know, I am a middle school teacher. Unless you are a teacher, you probably don't know how wild and crazy that life can be depending on the students, parents and staff. Well, this has been one of those crazy years. Not crazy bad, just crazy busy.

Computers in the Classroom

I am in the process of installing 30 Dell computers in my classroom. The goal is to have a computer with appropriate and consistent software for each student. The software the students will ultimately master consists of Open Office Writer and Impress. They will frequently use MS Paint, ImageForge, Inkscape, Google Earth, Marplot and QGIS or a similar mapping package. Each computer has a high-speed Internet connection, allowing the students opportunities to research projects using on-line resources. Using the suite of software I've installed, the students are able to accomplish almost all classroom tasks, submit completed assignments and receive graded assignments all without resorting to paper copy. My ultimate aim is to ensure each student masters word-processing and presentation software. I want them to prepare high school and college assignments and submit them with confidence derived from extensive experience.

Back to Bennet Island

I like what I've done with this ice covered island so far. At first I traced a shoreline that was an educated guess. The more I've mapped this island, the more I've decided that an ice covered island with rock outcroppings is best mapped as shown above. Map the land that is visible and leave the ice as ice. My busy life, mi vida loca, makes the completion of this map a distant dream. But, finish it I will. Yes, just as soon as I finish teaching my students, installing a room full of computers, cleaning my weed chocked backyard, paying my bills, etcetera, etcetera, etceteera...

Enjoy!

Sunday, April 19, 2009

Comparison - NGA PGS to EVS Precision Vectors

Comparison - NGA PGS to EVS Precision Vectors (1-6,250)

Comparison - NGA PGS to EVS Precision Vectors (1:6,250)

I know a good deal about global shoreline vector files. Specifically, global shoreline vector files that are free, available to the public and relatively easy to load and work with. This post's focus is a comparison of NGA's Prototype Global Shoreline (PGS) to Enhanced Vector Shoreline (EVS) Precision shorelines. This is not my first comparison of these two shorelines and it probably won't be my last, but here it goes.

NGA PGS vectors too often wobble off of the imaged coastline unnecessarily. The NGA PGS vectors were derived from Landsat ETM+ imagery, the same imagery I use to create EVS Precision shorelines. The above image is a small portion of Somalia's shoreline. The Landsat image is cloud free and the shoreline is easily distinguishable. NGA PGS used a complicated formula to determine the shoreline, but I don't see why their vectors misplot by as much as 41 meters from the imaged shoreline. No, this doesn't happen all of the time, but it happens enough, that if I am working at very large scales (1:50,000 to 1:12,500), I must redo the shoreline. Their shoreline is too far from image shoreline true.

I've been doing EVS Precision mapping for over 9 going on 10 years and my opinion concerning NGA PGS has not changed. Don't get me wrong, NGA PGS is the most detailed global shoreline available, one that I recommend heartily. However, for my work, creating detailed island maps, it isn't good enough.

Enjoy!

Saturday, April 18, 2009

Jasiira Mayhd SO - A Home for Pirates or A Home for the Birds?


View EVS Islands Projects in a larger map


Jasira Maydh - Landsat ETM+ Image N-38-10_2000 (1-25,000)

Jasira Maydh - Landsat ETM+ Image N-38-10_2000 (1:25,000)


Jasira Maydh - EVS Precision Map (1-25,000)

Jasira Maydh - EVS Precision Map (1:25,000)


SO002 JASIIRA MAYDH

Country/Territory

Somalia


Administrative region(s)

Sanaag


Central coordinates

47o 15' East 11o 14' North Map


Area

45 ha


Altitude

0 - 124m


Criteria

A4i, A4iii

Site description Jasiira Maydh or Mait island is located in the Gulf of Aden c.13 km offshore, to the north of the town of Maydh and hence adjacent to Daalo (site SO003). It is a little over 1.5 km in length with a maximum width of 300 m and an average height of 100 m. The long axis of the island is oriented from east-north-east to west-south-west. The island is steep-sided, rising abruptly out of the sea, and along the southern face rocky buttresses alternate with scree-filled gullies while the northern face is an unbroken precipice. The rock is granitic gneiss which is covered with guano deposits, and the surface is split in places by great fissures. The island is completely lacking in vegetation and there is no fresh water except after rain, of which there is only c.50 mm per year. The island lies within an area of seasonal coastal upwelling.

Land-use and percentage cover

other

-


Birds See Box for key species. In addition, Phalacrocorax nigrogularis has been recorded while other breeding species include Phaethon aethereus, Sula dactylatra, Sterna fuscata and S. anaethetus (the latter two in 'large numbers'). In the 1940s, the numbers of breeding birds present was estimated at c.100,000, but were reported then to be declining. The breeding season is June-September, after which nearly all birds leave.

Species

Season

Year

Min

Max

Quality

Criteria

Brown Noddy (Anous stolidus)breeding19792000020000-A4i
A4iii (Species group - waterbirds)breeding000unknownA4iii

Conservation issues The island has been proposed as a marine protected area. Guano is collected from the island, but traditionally only from October to April, i.e. when the birds are absent. During the breeding season the seas are generally too rough to permit boats to land, which prevents disturbance. Rats and snakes are present on the island.

Citation BirdLife International 2008 BirdLife's online World Bird Database: the site for bird conservation. Version 2.1. Cambridge, UK: BirdLife International. Available: http://www.birdlife.org (accessed 19/4/2009)

__________________________________________________________________

Yes, I nabbed the above information from Birdlife International. It makes sense that an island would figure in as a safe habitat in the world of birds. Islands are typically safe havens for many of our feathered friends.

Mayhd town, located about 10 kms to the south of Mayhd Island is reputed to be one of many pirate strongholds along this coast of Somaliland. I suspect that if pirates use this island it would be as a shield prior to attacks on ships. May the pirates disappear and the birds remain forever.

Enjoy!

Friday, April 17, 2009

How To Make A Really Big Map

New Britain Island - Landsat ETM+ S-56-00_2000 Image Resized (1-375,000) Northwestern End

New Britain Island - Landsat ETM+ S-56-00_2000 Image (1-375,000) Northwestern End


New Britain Island - EVS Precision Map (1-75,000) Northwestern End

New Britain Island - EVS Precision Map (1:75,000) Northwestern End (Select image to see full-size)

I'm such a pushover when it comes to reader-requested mapping projects. Some of the projects are relatively simple (a single island with a couple of layers of information), others more complex (a single island with many layers of information) and finally the very complex or lengthy mapping project consisting of many layers of information or covering a large area with a variety of detail. My last mapping project, the northwestern end of New Britain Island, covered a large area and the reader was keenly interested in the offshore reefs.

Back in January 2009 the reader's initial query was deceptively simple, "Have you done any reefs in New Britain, Papua New Guinea?" During the summer of 2008, I had mapped all of the islands located between and including Papua New Guinea to the Cook Islands which consisted of over 10,000 island polygons using Landsat ETM+ as my base imagery. One of those islands was New Britain. I figured the project would be a snap. The reader was only interested in the northwestern end of New Britain. I would ensure my original island polygon was sufficiently accurate and then I would digitize and classify all reefs into a single vector layer called Reef Shallow. No problem!

Along with trying to be an attentive husband, loving father, generous grandfather, concerned and effective teacher and all-around good guy, my life got very busy. So busy that the New Britain Reef project got pushed behind my busy life. I informed the reader that I would have to table his project for the time being and since the project was "gratis", he waited. And so the New Britain Reef project resided in my computer waiting for my return. All of the shoreline was finished along with a portion of the reefs. My initial work had taken about 20-hours to complete. The week before last, the patient reader asked if I would have an opportunity to complete the project. Frankly, I had forgotten about it. Feeling guilty for not completing it way back when and knowing that I had a week's vacation coming, I promised to finish the project. And I did! It took about 10 more hours, but I finished it!

I studied my completed work and realized that this mapped area was really large. Since this reader did not require my vector files, I would have normally sent the reader a screenshot (raster image) the size of an 8.5 X 11 page of their project and that would be the end of it. However, this reader would be unable to appreciate the detailed reef information at that scale (1:350,000). I decided to construct a large format map at a scale of 1:75,000 giving the reader sufficient detail for his ultimate purpose, finding new fishing locations.


New Britain Island - EVS Precision Map (1-75,000) Northwestern End with Grids and Labels

New Britain Island - EVS Precision Map (1-75,000) Northwestern End with Map Tile Labels


W3

1 of 15 EVS Precision Map Tiles (W3)

I have constructed numerous image mosaics, but never a map mosaic. Using images from Global Mapper and mosaicking them into a single image using Image Forge software and finally constructing lat/lon grid lines in MS Draw, I created "a really big map" (thus the title of this post). All of you mapping professionals, calm down. I know mapping software exists that will make "a really big map" in a single step. Typically, it costs money and that's something I don't have much of. Anyway, back to my mosaicked map. "The really big map" consists of 15 tiles , each tile similar to the one displayed in the above image. My final map is 3050 X 4220 pixels in size or about 65 x 89 cms (25.5" x 35").

My final thought, I've got to start charging for my work! I spent 30+ hours on this project. At a modest fee of $20 per hour, I should have made $600 for this project. Instead, New Britain Island's northwestern end is mapped in great detail and I'm none the richer for it.

Enjoy!

Wednesday, April 15, 2009

Musandam Peninsula OM - A Revisit of a Previous Post


View EVS Islands Projects in a larger map


Oman - Landsat ETM+ N-40-25_2000 (1-175,000)

Oman - Landsat ETM+ N-40-25_2000 (1:175,000)


Oman - EVS Precision Map (1-175,000)

Musandam Peninsula - EVS Precision Map (1-175,000)


Musandam Peninsula - EVS Precision Map with 50-Meter Contour Intervals (1-175,000)

Musandam Peninsula - EVS Precision Map with 50-Meter Contour Intervals (1:175,000)

The above EVS Precision map project of the Musandam Peninsula was completed around the first week in September 2008. It was my last mapping "hurrah" before the start of this school year. I remember loving the look of this unusual piece of land calling it a "peninsula of peninulas.


Musandam Peninsula Oman from EO (musandam_AST_2004067_lrg) Resized

Musandam Peninsula, Oman from Earth Observatory (EO)

It seems that the folks at EO dusted off a 2004 ASTER image of the Musandam Peninsula and posted it to their site today. The peninsula is still lovely to look at!

Enjoy!

Tuesday, March 24, 2009

Manihi Atoll FP - First Landfall in the Tuamotus


Manihi Atoll Locator Map


Manihi Atoll - Landsat ETM+ Image S-06-10_2000 (1-110,000)

Manihi Atoll - Landsat ETM+ Image S-06-10_2000 (1:110,000)


Manihi Atoll - EVS Precision Map (1-110,000)

Manihi Atoll - EVS Precision Map (1-110,000)

Manihi Atoll is one of French Polynesia's premier destinations for the tourist wishing to view pearl farming first hand. According to the Tahiti Tourism North America, Manihi Atoll has over 60 working pearl farms. While one is looking for those perfect pearls, the Manihi Pearl Beach Lodge beckons. This atoll is one of the first landfalls for the visiting yatchsmen traveling from the Marquesas to Tahiti.


Manihi map-big (500)

Manihi Atoll - Pacific-Image Map

In doing research for Manihi Atoll I came across the Pacific-Image map. As to names of the various motus, it is complete. As to cartographic quality, it looks like a map, it seems like a map, and it is a map, one designed for the tourist. If you are into high quality tourist maps of Pacific Islands, specifically the islands of French Polynesia, for only $237.60 you can purchase a CD loaded with 72 of these very attractive maps.


Detail Manihi Map Image-Pacific

Manihi Atoll - Detail from Image Pacific Map


Manihi Atoll - EVS Precision Map - Detail Tairapa Pass and Paeua (1-30,000)

Manihi Atoll - EVS Precision Map - Detail Tairapa Pass and Paeua (1:30,000)

Although the Tahiti Pacific-Image maps are excellent for their purpose, I like mine better. Compared to the Tahiti Pacific-Image map, my EVS precision map of Manihi Atoll takes into account a wider variety of layers of information. In addition, my maps are vectors, whereas Tahiti Pacific-Image's maps are raster images.

As to the production of this map, it was not particularly difficult to digitize and ultimately create the island map. However, my very busy life caught up with me and what should have been a 10-hour project, took two weeks to complete. I have other island projects in the works, but they will be completed and posted at this much slower pace. Until then...

Enjoy!