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NEWSCIENCENEWSCIENCENEWSCIENCE in the form of Google Earth Another disadvantage of mile spacing is used to show the screenshots, as long as you gave it precalculated maps is that they may major lines of the system, even proper credit and didn't charge not be at a resolution that you want though, theoretically, the World Grid people for viewing them. to use. is infinite. It has to be infinite in The Google Earth team provided Initially, Bruce learned that the order to create the reality of the something else which made a world World Grid system was laid out on a__ planet on which we live. of difference to researchers like us: system of grid lines 30 minutes (30') We found over time that they published their file specification and encouraged people to use it to create Google Earth-compatible files. That's what we decided to do, and that's why Gridpoint Atlas does not display Google Earth researchers who purchased our software wanted different resolutions from the 30' and 7.5’ divisions which we provided. We then included a facility where a person could enter their own grid resolution, as long as it was an harmonic of 360 imagery and why it is a degrees. separate product. For our examination of the When you plot the World Argonne National Grid® in Gridpoint Atlas, a Google Earth- compatible file is also created, and in turn the file is displayed in Google Earth. From a Laboratory, we will use a grid resolution of 7.5 minutes of arc. To begin our study of this locale, we will oad Google Earth and zoom user's perspective, it is like in on the Argonne National you are moving from one Laboratory. Figure 6 isa piece of software to Figure 6: Argonne National Laboratory screenshot from Google another—except for the (screenshot source: Google Earth) Earth of the area. fact that when you plot the We want to pick a centre grid in Gridpoint Atlas, the point in the area and take file is loaded into Google hat coordinate back to Earth automatically. An Gridpoint Atlas. We wil example will illustrate this. choose 41.703877° There are many atitude and 87.984228° W interesting sites around the ongitude. world that deserve our In Gridpoint Atlas, we wil attention. Let's start with oad the States layer of the he Argonne National United States map library. Laboratory in Argonne, Although you can load llinois, USA. We'll begin other map layers, such as our investigation of this cities, towns, rivers and ocation in Gridpoint Atlas major roads, we only need by understanding the to use one layer as a base philosophy of the Map layer for reference. window in the software. - After loading the States The software does not Figure 7: Map of the Argonne National Laboratory layer, we will place a marker ave precalculated World area with 75' grid overlay at the coordinate we chose Grid maps of the entire world. That in Google Earth. This marker will be is not really practical, as there would or 30 nautical miles apart. He also used to tell Google Earth what the be trillions and trillions of points in learned that the grid could be further centre of our area is. hose maps and when you loaded _ subdivided into a system of lines 7.5 Finally, we will plot the World Grid such a map into memory it would minutes (7.5') or 7.5 nautical miles by overlaying a 7.5' grid onto the bog down any computer system. apart. To this day, the 7.5-nautical- area, and we will indicate that we Another disadvantage of precalculated maps is that they may not be at a resolution that you want of to use. Initially, Bruce learned that the World Grid system was laid out on a system of grid lines 30 minutes (30') Figure 6: Argonne National Laboratory (screenshot source: Google Earth) or 30 nautical miles apart. He also learned that the grid could be further subdivided into a system of lines 7.5 minutes (7.5') or 7.5 nautical miles apart. To this day, the 7.5-nautical- 52 * NEXUS FEBRUARY - MARCH 2011 www.nexusmagazine.com