Same same, but different

Nice mapserver, enabling vector display as well. Based on GeoExt.

If you need to calculate the area of a polygon layer in ArcGIS, you can do so in ArcMap.

Use ArcGIS Desktop Help (available from the ArcMap interface) to get basic directions – under the Index, search for “area” – you should then see “Calculating for Polygons”

These directions have been tested and they work well. However, before you do this, there are some things you need to check.

A note about coordinate systems and area calculations
First, make sure that your data layer is in a defined projected coordinate system, like State Plane or UTM. You need to know what the map units of the data layer are (usually feet or meters), because once you calculate area, the area calculation will be in those map units.

If your data is not projected (e.g., it is in a Geographic Coordinate System, meaning decimal degrees) it would be wise to project it first. In the Data Frame Properties, change the coordinate system to a projected coordinate system (e.g., State Plane NAD83 (feet) Texas Central. Then right click on the data layer and choose Export Data. In the dialog box that follows, choose to create the new data set in the Data Frame’s coordiante system (now set to a projected system). This will create a new projected data layer, that you can then add to the Data Frame. From that point, you can follow the directions in ArcGIS Desktop Help for calculating area. If the data frame units were in feet, the area calculation will be square feet.

To convert square feet into square miles or acres or hectares, you need to add a new field to the attribute table (e.g., sq_mile), then use the Calculate Values tool to have that field = the area field x the conversion factor. To get the conversion factor, see Peter Wallin’s the Conversion Table for changing measurement units.

Creating an “area” field in your attribute table if you don’t already have one
If your attribute table does not already have an “area” field, you need to create one before doing the area calculations. You can create the new field in ArcCatalog or ArcMap. Note you can add an acres field using these same directions.

To create a new attribute field for “area” in ArcMap, follow these directions – note you cannot be in an editing session to do this (don’t ask me why):

• Open the layer’s attribute table in ArcMap
• Click on the Options tab
• Choose Add Field
• Name it Area
• For Type, choose Double
• Don’t put anything under Precision or Scale.
• Click OK

Calculating area for polygons (from ArcGIS Desktop Help)

• Open the attribute table of the layer you want to edit.
• Right-click the field heading for area (if there is no field for area values, you can add a new field for area by clicking the Options button and selecting the new field option).
• Click Calculate Values.
• Checkmark the Advanced box (this is important – dont’ forget this!)
• Type the following VBA statement in the first text box (you should be able to copy and paste):
  Dim dblArea as double
  Dim pArea as IArea
  Set pArea = [shape]
  dblArea = pArea.area
• Type the variable dblArea in the second text box (near the bottom of the dialog box) directly under the area field name.
• Click OK.

Source

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Datamob highlights the connection between public data sources and the interfaces people are building for them.

Testing WMS Feature of the GEO Data Portal.

Very nice slides!

“Too much and too long, we seem to have surrendered community excellence and community values in the mere accumulation of material things. Our gross national product … if we should judge America by that – counts air pollution and cigarette advertising, and ambulances to clear our highways of carnage. It counts special locks for our doors and the jails for those who break them. It counts the destruction of our redwoods and the loss of our natural wonder in chaotic sprawl. It counts napalm and the cost of a nuclear warhead, and armored cars for police who fight riots in our streets. It counts Whitman’s rifle and Speck’s knife, and the television programs which glorify violence in order to sell toys to our children.

Yet the gross national product does not allow for the health of our children, the quality of their education, or the joy of their play. It does not include the beauty of our poetry or the strength of our marriages; the intelligence of our public debate or the integrity of our public officials. It measures neither our wit nor our courage; neither our wisdom nor our learning; neither our compassion nor our devotion to our country; it measures everything, in short, except that which makes life worthwhile. And it tells us everything about America except why we are proud that we are Americans.”

Robert F. Kennedy

Adobe® kuler is an online community where you can explore, create, and share color themes. The color themes in kuler are contributed by its users, many of them designers or in the creative business. You can share with the community your own chromatic ingenuity, too.

Lithoglyph’s Mondrianum enables Mac applications to leverage the resources of the kuler community. Once installed, Mondrianum acts like a built-in, system-wide color picker, available in any Mac application that supports this feature of Mac OS X. Apple’s own iWork™ and iLife® suites, Google Sketchup™, Adobe® Photoshop®, and renowned applications like Coda, CSSEdit, and many more, all work well with Mondrianum.

It seems like 99 percent of the mail we send is electronic these days. The other 1 percent is letters and postcards that we want to postmark with our (usually enviable) location for the recipient. That’s why we dig these uber-accurate Google Maps envelopes.
Source

Natural Earth is a public domain map dataset available at 1:10m, 1:50m, and 1:110m scales. Featuring tightly integrated vector and raster data, with Natural Earth you can make a variety of visually pleasing, well-crafted maps with cartography or GIS software. Natural Earth Browser here.

Mousepointer movements and clicks after one hour of working, browsing etc. Nice app from here (Mac) and here (Windows).

BookBook is a one-of-a-kind, hardback leather case designed exclusively for MacBook and MacBook Pro. Available in Classic Black or Vibrant Red, BookBook brings three levels of security to your prized Mac. First, the hardback cover and spine provide solid protection from the rigors of the road. Second, the vintage book design disguises MacBook for superior security. And third, the stylish case protects you from being like everyone else because BookBook is totally original, just like you.

Between science and art: Commercial shipping activity can lead to ship strikes of large animals, noise pollution, and a risk of ship groundings or sinkings. Ships from many countries voluntarily participate in collecting meteorological data globally, and therefore also 7 report the location of the ship. We used data collected from 12 months beginning October 2004 (collected as part of the World Meteorological Organization Voluntary Observing Ships Scheme; http://www.vos.noaa.gov/vos_scheme.shtml) as this year had the most ships with vetted protocols and so provides the most representative estimate of global ship locations. The data include unique identifier codes for ships (mobile or a single datum) and stationary buoys and oil platforms (multiple data at a fixed location); we removed all stationary and single point ship data, leaving 1,189,127 mobile ship data points from a total of 3,374 commercial and research vessels, representing roughly 11% of the 30,851 merchant ships >1000 gross tonnage at sea in 2005 (S14). We then connected all mobile ship data to create ship tracks, under the assumption that ships travel in straight lines (a reasonable assumption since ships minimize travel distance in an effort to minimize fuel costs). Finally, we removed any tracks that crossed land (e.g. a single ship that records its location in the Atlantic and the Pacific would have a track connected across North America), buffered the remaining 799,853 line segments to be 1 km wide to account for the width of shipping lanes, summed all buffered line segments to account for overlapping ship tracks, and converted summed ship tracks to raster data. This produced 1 km2 raster cells with values ranging from 0 to 1,158, the maximum number of ship tracks recorded in a single 1 km2 cell.
Because the VOS program is voluntary, much commercial shipping traffic is not captured by these data. Therefore our estimates of the impact of shipping are biased (in an unknown way) to locations and types of ships engaged in the program. In particular, high traffic locations may be strongly underestimated, although the relative impact on these areas versus low-traffic areas appears to be well-captured by the available data (Fig. S2), and areas identified as without shipping may actually have low levels of ship traffic. Furthermore, because ships report their location with varying distance between signals, ship tracks are estimates of the actual shipping route taken.
What happens in the vast stretches of the world’s oceans – both wondrous and worrisome – has too often been out of sight, out of mind. The sea represents the last major scientific frontier on planet earth – a place where expeditions continue to discover not only new species, but even new phyla. The role of these species in the ecosystem, where they sit in the tree of life, and how they respond to environmental changes really do constitute mysteries of the deep. Despite technological advances that now allow people to access, exploit or affect nearly all parts of the ocean, we still understand very little of the ocean’s biodiversity and how it is changing under our influence. The goal of the research presented here is to estimate and visualize, for the first time, the global impact humans are having on the ocean’s ecosystems. Our analysis, published in Science February 15, 2008, shows that over 40% of the world’s oceans are heavily affected by human activities and few if any areas remain untouched.