Lining Up Data in ArcGIS: A Guide to Map Projections is an easy-to-navigate troubleshooting reference for any GIS user with the common problem of data misalignment. There are numerous scholarly volumes that delve into the mathematics of map projections… Data misalignment is one of the biggest issues faced by GIS users. As a member of the ESRI support services team, author Margaret Maher has handled more than 12,000 incidents relating to projections and data conversion. 'Lining Up Data in ArcGIS' is a practical guide to solving these problems, based on Maher's decade of experience helping GIS users. This book presents techniques to identify data projections and create custom projections to align data. Formatted for practical use, each chapter can stand alone, addressing specific issues related to working with coordinate systems. 'Lining Up Data in ArcGIS: A Guide to Map Projections' is a handbook that will benefit new and skilled GIS users alike. Example in which data with the unknown coordinate system is in a GCS, and reference data is in a projected coordinate system Source.