Marokau and Ravahere Atolls - EVS Precision Map, Google Map, Yahoo! Map, MS Live Search Map, and MS MapPoint Map

Marokau and Ravahere Atolls - EVS Precision Map (1:250,000)

I am mapping my way through the Tuamotus, with a goal of having EVS Precision maps for all islands located in the South Pacific. I finished mapping shorelines and reefs for Marokau and Ravahere Atolls. The atolls have a reported population of 50 plus. The folks make a living off of copra, fishing and pearling. The eastern edge of Marokau's long motu has a number of pools, most probably saltwater created from heavy surf during a storm. It sure does make one ponder the tenuous life lived on a 1 to 2 meter high atoll.

Interesting, but not the complete reason for sharing this post. Let's take a look at how the big three internet map moguls handled these tiny jewels.

Marokau and Ravahere Atolls - Google Map (1:800,000)

Google Maps - Their shorelines are DCW (Digital Chart of the World). 1:1,000,000 is as good as it gets with Google Maps. Actually, the above map is at a scale of approximately 1:800,000. That was the closest I could zoom. I've had people tell me these maps are intended for routing and coarse direction finding. I think that is all one could hope for. DCW was a heck of a map during the infancy of the Internet. Now it is a mapping dinosaur, depicting shorelines with a very crude degree of detail.

Marokau and Ravahere Atolls - Yahoo! Map (1:300,000)

At least Yahoo! lets us zoom in to approximately 1:300,000 scale. Their map also includes the atoll names. Nice touch, but still DCW shorelines.

Almost ditto with Yahoo!'s map. MS Virtual Earth included the names of two villages found on these atolls. They neglected to include the names of the atolls, but we do have the villages named.

Marokau and Ravahere Atolls - MS MapPoint Map (1:400,000)

MS MapPoint can be found at a number of sites. It is an MS product that sells for between $250 to $70. At first glance, it looks to be a significant improvement over the DCW derived maps. However, it isn't. It is still a DCW derived map. The motus have a nifty blue ring around them and a reef feature ringing the atoll is identified. The reef feature is standard with any DCW country download. However the nifty blue rings around the motus looks to be a motu enhancer. The names are from NGA Country Files and the bathymetry is DCW standard issue.

This is the data world in action - take free government data, package it and sell it again and again! I acknowledge that TeleAtlas and Navteq should focus their mapping efforts on streets and roads within major cities. That is their cash cow. But to still be using DCW shorelines in many places throughout the world is silly. I'm sure that money dictates their every mapping decision. In this case, map quality should be the overwhelming determinant.

When my maps are consistently of far greater quality than Google, Yahoo! or MicroSoft or of their map providers, Teleatlas and Navteq, something is out of wack . . . and it isn't me and my maps. TeleAtlas and Navteq needs to spend a few bucks to upgrade their shorelines. WVS would be a significant upgrade over their current shorelines. For island shorelines, EVS precision vectors are the only way to go.

Enjoy!

Comparison - DCW, VMAP0 Shorelines and GYM's Mapping Opportunity

Shoreline Map Comparison - Yahoo, Google, MS and EVS Precison

Shoreline Map Comparison - DCW and VMAP0

This post shows that Google Maps, Yahoo Maps and MS Live Search Maps use DCW/VMAP0 global shorelines for their mapping, at least in the area of Rabul. That is 1:1,000,000 scale global map coverage. James Fee, a well-respected GIS professional, commented, "When it comes to precision, I think the efforts for GYM (Google, Yahoo, Microsoft) should be on the navigation/geocoding/routing and not shorelines." First, one must agree with James' statement that GYM's maps are intended primarily for navigation/geocoding/routing. I believe that their customers, global in reach, would subject GYM's maps to many other GIS uses beyond navigation/geocoding/routing. I know that there is an agressive effort within the GIS community to provide a richer, more powerful set of tools, allowing any of us the opportunity to explore more complex spatial issues using Google Maps and Google Earth as platforms of choice. Ultimately, the end user, faced with a spatial problem requiring small scale maps would either have to make their own map, pay to have a map made, use a substandard map in place or not use a map at all.

In addition, James seems to suggest that 1:1,000,000 scale is satisfactory for GYMs primary efforts of navigation/geocoding/routing. I understand his reasoning, but I disagree. Before teaching, I did extensive geocoding of environmental risks. Locational precision was critically important. 1:1,000,000 was an unworkable geocoding scale. To follow the flight path of an enemy aircraft using 1:1,000,000 is doable. However, to locate enironmental risks at that large of a scale is asking for problems. A misplotted environmental risk could well result in a lawsuit. Business locations was another area I worked in and locational precision determined an exclusive market and was a contractual promise to the franchisee.

James goes on to say, "For me the shorelines are somewhat irrelevant to the routing provided. If I do need good shorelines, I'll probably just be using the aerial imagery in the first place." Again, his reasoning seems to make sense, but I disagree. First, shorelines are not somewhat irrelevant, they are a dynamic boundary between man and water. A raster image of a shoreline is practical for some applications, but a vector defined shoreline offer one a wide range of mapping possibilities. If I am GYM's map guru, I want my customers to have the greatest mapping precision possible. I don't want to impose precision limitations when there is no need. EVS precision shorelines, on a global scale, requires money to fund the mapping effort and time to complete the project. It will be money well spent. The resulting shorelines and other feature/land use layers will allow the "G", the "Y" or the "M" to be the number one mapping destination for all users and that could generate lots of ad dollars.

Finally, vector maps allow for infinite zooming with no lose of detail. If the initial vectors are created from quality base imagery (i.e., Landsat ETM+) and the map customers are able to easily access these detailed vector maps, they can tackle complex spatial issues using GYM's hi-precision mapping. Thus a marketing boon to the company savy enough to provide the product.

Enjoy!

P.S. - After yesterday's post, I received a query from an individual about EVS precision mapping for a section of Canadian shoreline. He had used WVS/GHHS vectors and they were unsatisfactory for his project. I sent him NGA PGS vectors covering his target area. They looked okay at 1:250,000 scale. He loaded them and acknowledged they were a significant improvement over the WVS/GHHS vectors, but were angular and did not track a cloud-free shoreline as one would expect. I created EVS precision vectors for him. He compared them to NGA PGS vectors and immediately acknowledged their higher quality. He asked if I would go ahead and create EVS precision vectors for his entire study area. I will, but wouldn't it have been cool for him to go to one of the big three mapping portals and find this mapping not only available, but downloadable? I think so.

Comparison - Google Maps, Yahoo Maps, MS Live Search Maps and EVS Precision Maps

Shoreline Map Comparison - Yahoo, Google, MS and EVS Precison

Whose shoreline maps are currently the most accurate? Is it Google Maps? They have loads of bucks and a keen desire to put the best product into their sites. They must have the most accurate shorelines. Right? Nope, not them. Yahoo! Maps, the current darling of the stock market and Google "wannabe", has the same clunky shoreline used by Google. MS Live Search Maps has the prettiest maps. Lots of shaded hills and valleys, but clunky shorelines. For sure, MicroSoft must have the most accurate shorelines. For sure, not.

Would you believe, EVS Precision Maps has the most accurate shorelines compared to the big three map moguls. EVS precision mapping is derived from Landsat ETM+. Typically, it provides accurate shoreline depiction at scales between 1:100,000 to 1:50,000.

Rabul - MS Live Search Map

All map maker struggle with PPL (populated place) placement. The PPL data is available through NGA. I'm reasonably certain most of their data and locational information was derived from ONC (1:1,000,000) charts. Looking at the PPLs on the MS Live Search Map of the Rabul area, we see towns lined up in a grid. In the real world, this only happens in the midwest, not on New Britain Island in Papua New Guinea. One should replot these PPLs using Landsat ETM+ or hi-res imagery. The only thing certain about the above plots, is their locational uncertainty. But, back to shorelines.

Rabul - EVS Precision Maps

EVS Precision Maps provide the most accurate shoreline maps of the four being compared. The big three use, what appears to be DCW's 1:1,000,000 shorelines. 1:1,000,000 has it's uses, but when one zooms to 1:63,500 (1" to 1-mi), a shoreline that approximates reality is expected. EVS Precision Maps show that expected shoreline. Google Maps, MS Live Search Maps and Yahoo Maps do not.

Enjoy!

P.S. - I am aware of NGA PGS vector files, 24 tiles covering much of the world. They were derived from Landsat ETM+. EVS Precision Maps and NGA PGS should parallel each other. They do not. NGA PGS vectors used a digitizing algorithm to automate their work. Peculiar stutters, uncalled for strings of vectors and angular shorelines are often the norm. Also, NGA requested that water inundated areas (swamps, marshes, tidal flats) be excluded. This caused a great many problems in shoreline mapping. Also, the slightest cloud cover often thwarted their automated digitizing efforts. EVS Precision Maps consistently improve upon NGA PGS.