Spatial Accuracy of Online Mapping Systems

Just as a quick test. How spatially accurate are the online map systems?

Reference

Google Maps 164.592m - Accurate ✓

Google Earth 163.99m - Accurate ✓

ESRI ArcGIS Online 164.7m - Accurate ✓

Bing Maps Unknown Distance (Map Distance App is no longer available).

From this view, it would appear that geo-registration and referencing of the imagery on the WGS84 datum is pretty accurate from the standpoint of Google and ESRI.  Both  ESRI and Bing are using the same imagery for this location in the world, but whether or not the Bing map is registered correctly to reflect the standard given in the first figure, remains to be seen. 

A interesting journal article recently published in Cartographica 49:3, 2014, pp. 164–174, by Andrea Favretto, entitled Coordinate Questions in the Web Environment inspired this blog entry. In the article, Faveretto examines different projections and representations of earth in the digital mapping environments. He demonstrates some inconsistencies.

Here is one of his main figures (page 117) replicated for educational information here:

It would appear that in his examples there are problems with the distances and the registration. However, he does not give the statistical accuracy related to the reliability of the horizontal accuracy of the GPS unit that was used to create the points on image d in Figure 1. directly above.

Spatial Perspective

I love the ocean.

When I see the immensity of the water with the boundless distance of blue I am reminded at how frail, small, and utterly dependent I am.

I love that.

My shoulders relax, my mind wanders, my breath slows, my joy grows.

The ocean gives me renewed spatial perspective. I realize my world actually is quite small compared with the rest of the world. My complaints seem irrelevant - does it really matter that there are a few too many cars in front of me slowing me down to my destination? No, not really.

Understanding my place and space and the positive affect I hope to have means so much more than my complaints, which usually are fruitless. Sure, I want to be justified in my complaint, but perhaps I should leave that justification more to the Creator. My shoulders might relax in my humility, just like at the ocean, when instead of complaining, I take joy in the joy I have: my wife, my children, my friends and relationships that do matter. That would be nice.

This map shows the size of Grand Rapids compared to the sprawl of Houston, Texas. So often I am ignorant of others; of their needs, of their place, of their world I know not. Millions live within those polygons represented here. Each has a hurt, a joy, a secret, a love. Today, take the opportunity to tell those you love, that you do indeed love them & smile at strangers too. Limit your complaints and increase your joy.

Go visit the nearest ocean for a while too. 

Whither Cartography?

In past decades, several journal articles have surfaced related to the question of whither.

Not to be confused with wither, whither is a term that means 'to which place' or 'where'.  Articles like:

1. Whither Political Geography? - Jackson 1958  Annals of the Association of American Geographers, 178-183, Volume 48, Issue 2,
2. Whither Geography? - Van Cleef 1971 The Professional Geographer, 344-346, Volume 23, Issue 4,
3. Whither Electral Geography? - Rumley 1975 Annals of the Association of American Geographers, 342-343, Volume 65, Issue 2,
4. Whither Spatial Statistics? - Gaile 1990 The Professional Geographer, 95-100, Volume 42, Issue 1,
5. Whither Geography? - Harman 2003 The Professional Geographer, 415-421, Volume 55, Issue 4,
6. Whiter Parity? The Need for a Comprehensive Curriculum in Human-Environment Geography Yarnal & Neff 2004 The Professional Geographer, 28-56, Volume 56, Issue 1,
7. Whither Physical Geography? - Rhoads 2004 Annals of the Association of American Geographers, 748-755, Volume 94, Issue 4,
8."Whither Geography?" Concluded: Is Geography Graduate Education Mission One of Its Targets? - Harmon 2005, The Professional Geographer, 130-139, Volume 57, Issue 1,
9.  Whither Critical Inquiry - Pendras 2006 The Professional Geographer, 99-103, Volume 58, Issue 1

So I ask Whither Cartography?

The relevance of cartography seems to be at all-time high. Everyone is a cartographer.  Online maps and mapping make it possible for all people to make maps. Just check out Google Maps and you can make a directional map for walking between points A & B.

But is everyone really a cartographer? This answer is no. Cartography is much more than just making an online map. It about directed communication. Applications like http://mapapps.esri.com/create-map/index.html , help us distinguish between the mundane general reference and the thematic.

The future certainly is in the creation of online thematic application maps. KML is a whole new world for creativity and the best of the Look of Maps. So go and be creative and communicate your message and apply the art and science of cartography.

Map courtesy of one of my excellent students, Seth K.

Food Islands?

Presently, food deserts are all the rage. But as one of my teaching assistants just pointed out, what about food islands? What about those places where food is plentiful in the urban environment - how well are they actually doing to serve the public a healthy choice for a fair value?

Not necessarily an easy question to answer, but I would point out that that more we focus on our attention on healthier choice from the supermarket, the healthier we will be. Are the days of globalized food ending? Probably not, but surely local supermarkets supported by local farmers must increase if we are ever to see our food islands truly affect change in our food deserts.

Map courtesy of one of my excellent students - Owen S.

The Power of Local

Now that gas prices have increased dramatically and “Price Creep” is raising the cost of goods from diapers to food stuffs, now is the time to invest in local markets.

Shopping in local oriented markets curbs the price creep phenomena in many ways because of distance. If you are getting your milk from a local dairy farm or a farmer’s market, chances are you probably will see very little if any increase in cost – the distance for the farmer is short and gas is hardly a factor. If you are now paying more for milk, why not seek out your local options and get healthier food for the same cost?
Buy local – support local. The power of local can change us all.

Bin Laden

Spatial analysis and fighting terrorism go together. My dissertation explores the intersections.

Colleagues at UCLA found this to be true too as they worked to combine island biogeography theory with terrorism to build on age-old spatial statistics of probabilities of where Osama Bin Laden might be located. Their paper demonstrates the power of the First Law of Geography: “Everything is related to everything else, but near things are more related than distant things.” (Tobler 1970).

Tobler W., (1970) “A computer movie simulating urban growth in the Detroit region”. Economic Geography, 46(2): 234-240.