Tip: Once you've created a farm project, you can return to the farm in the clipper Web app using MMP Tools | Clipper Web App | Go to Current Project's Farm. This can be useful if you need a larger clipped area or want to update your project with the latest base layers.
A "layer" is either a shapefile or an image (photo) file. "Base layers" are layers that are provided for you by the clipper Web app or other data source. Examples of base layers include the photo, topo and soils layers -- you don't create these layers yourself.
A "shapefile" is a file of points, lines or polygons with an .shp extension (there will also be an .shx file and a .dbf file and usually a .prj file). A shapefile is often referred to as a "vector" layer.
An "image" file contains a photo in a commonly used format like JPEG, GeoTiff, or MrSid. An image file will have a .jpg, .tif or .sid extension. These image files will also have a "world" file with a .jgw, .tfw or .sdw extension that tells the GIS where the image is located in the world. An image file is often referred to as a "raster" layer.
If you use the clipper Web app, it creates a .jpg file and a .jgw file with "doqq" in the files' name to indicate that the aerial photo is part of a "digital orthophoto quarter quadrangle". The clipper Web app also creates a .jpg file and a .jgw file containing the USGS topographic map and includes "drg" in the files' name to indicate that the scanned topo image is a "digital raster graphic". In addition, the clipper Web app creates an .asc grid file with "dem" in the file's name to indicate that it contains "digital elevation model" data and a shapefile with "wbd" in the files' names to indicate the shapefile contains "watershed boundary dataset" data. When you create a farm project from a clipper .zip download, MMP Tools renames these files to the more readable "photo", "topo", "dem" and "watershed", respectively.
If you have an unclipped county-wide soil survey shapefile that you downloaded from the Soil Data Mart, you can clip a portion of it to use with your project:
Tips:
In many states you'll be able to clip recent, high-resolution, color images. Here are some brief instructions on how to clip a photo on the USGS site:
Tip: If you create multiple MapWindow farm projects for a single operation, you can still export the fields from all projects to a single MMP plan. Use MMP Tools | Export | Create MMP Plan with the first project to add its fields to a new plan. With the other projects, use MMP Tools | Export | Update MMP Plan, selecting the MMP plan file created for the first project, to add their fields to the same plan. Just be sure that the fields are uniquely named across all of the operation's farm projects.
Last updated: July 20, 2015
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