The first object created when ArcMap starts running is the "Map Document" (MXD file). This document serves as the primary container for managing the map layout, layers, data sources, and other project elements within ArcMap. The MXD file allows users to save their work and settings for future use.
data frame properties
data frame properties
Right click the field heading for your area field in the attribute table and click calculate geometry. Choose sq\km from the dropdown. Click OK
For example, there are few string values of "1-5", ">5", "0-0.9", and "<0" from one field in attribute table. Then I need to sort both "1-5" and ">5" to a new field. How do I make the field calculator for this? Thank you!
Open the attribute table of the polygon shapefile you want to calculate. Add a field called Area, double type. Right click on the field heading in the attribute table and choose calculate geometry. Area should be the default, you will have to choose sq\km from the dropdown. Click OK. The double type will give you plenty of accuracy (decimal places).
GIS is Geographic Information Systems. Simply put,it is software used for mapping. It can ingest myriad types of data, satellite data being just one kind. GIS software like ArcMap does not NEED satellite data. So I suppose your answer is from zero to an infinite number.
There are alternatives to Google Earth such as NASA World Wind from a desktop application perspective.Google Earth is available as a free and paid Pro version (no source code is available). NASA World Wind is open source project and source code is available. World Winddiffers from Google Earth in that there is no one and 'official' World Wind application, instead there are many demos and programs with different functionalities created both by NASA and users from around the world.For high-end GIS users ESRI sells a suite of 2-D and 3-D Map-related products (ArcGis, ArcMap, etc.)From a web browser context there is Google Maps, which is integrated with Google Earth and shows some of the same map data. No download or installation is required.There is also Microsoft's Bing Maps, formerly known as Virtual Earth, with their impressive "bird's eye" aerial photos.Other mapping web sites with satellite imagery are also available. See related questions and related links for more details.