Welcome to GIS Ag Maps. The main purpose is to show and provide information in order that GIS and remote sensing can be applied for different purposes (there is a focus on crop agriculture). An emphasis is on applying Landsat imagery, yield maps, LiDAR-based elevation data and derived layers, as well as free GIS software.
Information for above graphic from left to right (references): 1) Landsat 8 rendition; 2) Yield monitor in combine; 3) Airplane-based LiDAR acquisition depiction; 4) Unmanned Aerial Vehicle (UAV) with camera.
Free custom GIS data downloads are designed to be viewed in free Quantum GIS but files will open in other GIS software, such as ArcGIS. The downloads (and Quantum GIS) can be accessed to the left and are a way to learn about and work with Landsat imagery as well as LiDAR-based elevation data and derived layers.
Landsat has nearly global coverage and, depending on the application, may or may not need to have values converted from digital numbers (DNs) to reflectance. Landsat 7, 5, and 4 surface reflectance can be acquired for free from USGS EarthExplorer. The free tutorial at the top of the page shows how to covert Landsat 8 to surface reflectance. In regards to crop information on the website, Landsat is mainly applied to corn and soybeans but uses shown can apply to other crops. Different Landsat applications are described at left.
Landsat Color Composite, NIR, and Visible Bands
(Images are from Corn Belt, USA)
Yield monitor data contain important information but also have inherent errors that should be removed; data can be processed into maps that can be usefully analyzed and applied.
LiDAR elevation data are available from different sources. The USGS has acquired LiDAR for areas in the USA and made the data available for free on The National Map Viewer as 1/9 arc-second (approximately 3-meter resolution) raster products. When applying elevation data for any purpose it is important to realize there is error associated with elevation values and derived layers, such as slope angle. Details about accuracy are included in the GIS Slope Angle & Accuracy folder.
For questions or comments, please access Contact page.