You can easily calculated geometry in ArcMap with a few simple steps. Calculating geometry in ArcGIS allows you to find the area and perimeter of your polygons. Here are the step for calculating the area of a polygon using ArcGIS. These steps can also be replicated for calculating the perimeter of a polygon or the length of a line file. You can use these steps to find out the acreage of a polygon by loading in a GIS dataset that uses a map projection that uses US customary units (e.g. is in feet). First, open up an ArcGIS session and load in the polygon data you want to calculate the area on. Make sure your data is in a projection system. Next, select the polygon file that you want to calculate area on and right click. This will open up a menu of options for that layer. Select the “Open Attribute Table” to open up the associate attribute data for your polygon layer. In the upper left hand corner of the attribute table window, click on the Table Options icon to open up the menu options. Select the “add field” option. When the “add field” dialogue box appears, type in the name of the field that will store the area values (e.g. name it “area”). Select “double” as the field type. Next, set your precision and scale values. Precision is the total number of digits that can be stored in the field, counting on both sides of the decimal place. A precision of 3 means that there can be at maximum number of digits can be 3. Scale for floating and double fields is the number of digits to the right of the decimal place. It is always better to overestimate the fields to avoid truncation of your values. Enter your values and hit the “OK” button to add the new field. Right click on the new field and select the “calculate geometry” option on the menu. Click “Yes” to move past the editing session warning that pops up. If you are working in a geographic coordinate system, you will not be able to calculate geometry. The calculate area and perimeter options will be disabled. ArcGIS uses planimetric algorithms to calculate geometry such as area and perimeter. To be able to calculate area, you will need to work with projected GIS data. There are two ways to do this: either load in projected data or load the data into a data frame that has a projected coordinate system (PCS) assigned to it. To set a PCS on a data frame, right click on the layer icon and select “properties” from the drop down menu. Then select the “coordinate system” tab and select a coordinate system from the options. This video demonstrates how to calculate the area of a polygon using ArcGIS 9.3. The video has no sound so make sure you select the “full screen” option in the lower righthand corner to see the steps taken to calculate geometry. City Maps: A coloring book for adults is a 94-page book containing 44 maps covering cities from around the world by Gretchen Peterson Sangeeta Deogawanka discusses what it takes to develop a career in Geointelligence whether it be in security, intelligence, policy analysis, first response, technology, software development or consulting. The American Association for the Advancement of Science (AAAS) has produced a manual entitled “Introduction to Remote Sensing of Cross Border Conflicts: A Guide for Analysts” as part of a project by its Geospatial Technology Project staff to understand the use of satellite imagery as a tool for “understanding border conflicts and possible conflict prevention.” Isodistance measures routes of equal time and isochrone measures routes of equal travel times although both are typically represented as bands of polygons. Got MS Excel? Need a simple map? A little known tool in older versions of Microsoft’s Excel is the ability to create simple maps from tabular data. You can create simple chloropeth, chart and dot density maps using data organized by country, state or region. An open source application by definition is software that you can freely access and modify the source code for. Open source projects typically are worked on by a community of volunteer programmers. Open source GIS programs are based on different base programming languages. Three main groups of open source GIS […] GIS is a technological field that incorporates geographical features with tabular data in order to map, analyze, and assess real-world problems. The key word to this technology is Geography – this means that some portion of the data is spatial. In other words, data that is in some way referenced to locations on the earth Source.