New layer information found here.
RGB stands for "Red / Green / Blue". This is a true-color representation of your field area, derived from the red, green, and blue layers of your 5-band Geotiff.
NRG, also referred to as CIR (color infrared), stands for "Near Infrared / Red / Green." This layer helps you to visualize the amount of infrared light reflected. Vegetation reflects a significant amount of near infrared light, making NRG very helpful. Red in the NRG layer represents the amount of near infrared reflection, green in the NRG layer represents the amount of red reflection, and blue in the NRG layer represents the amount of green reflection.
NDVI stands for "Normalized Difference Vegetation Index". NDVI is an index for visualizing vegetation health. Areas with NDVI values greater than 0.5 are colored using a red/yellow/green color scale. In general, most vegetation is found at NDVI values greater than 0.5. Thus, for ease of visualization, this layer does not show any areas with NDVI values that are less than 0.5. This means that areas within your fields that are less that have an NDVI value less than 0.5 will not be shown in this layer.
If you wish to visualize all NDVI values within your field, use the NDVI2 layer.
NDVI2 is calculated the same way as the NDVI layer (using the formula seen above). NDVI2 is differs from the NDVI layer in that a new color scale is applied, in which values below 0.5 are not hidden. This allows you to visualize all NDVI values within your field.
NDRE stands for "Normalized Difference Red Edge". This is calculated similar to NDVI, but this formula uses the RedEdge band instead of the Red band in the above formula. As plants mature, NDVI can plateau and may be less useful for measuring vegetation health. NDRE can be a more valuable index when collecting data and monitoring stress/health over mature plants.
DSM stands for "Digital Surface Model". It is generated as part of the photogrammetry process, and can be used to visualize changes in topography, or even measure the height of a plant or tree above the surrounding terrain. For more information on DSM accuracy, please see "How Accurate Is The Digital Surface Model Presented In ATLAS?"
Want to create your own indices or look at your data in another way? Check out our other help articles, "How Do I Work With MicaSense GeoTiff's In QGIS And Create A PDF Report?" or "How Do I Create An NDVI Or NDRE Using My MicaSense Multi-Layer GeoTiff In ArcMap?", about how to look at and work with downloaded GeoTiffs.