SlantRange terms and definitions

See this page for questions on specific terms and definitions.

A few notes: words shown in bold are references to on-screen options in SlantView and file explorer windows, and words shown in italics are common SlantView terms to become familiar with.

A list of common and potentially confusing SlantView Terms, in alphabetical order:

Color Scale

The Color Scale of the Stress Map should be adjusted based on the growth stage of the crops at the time of the flight. A field with a lot of bare soil and little crop content (early stage crops) may initially produce a map that displays a gradient of light red (relatively healthy areas) to dark red (relatively stressed areas). Alternatively, a field with a lot of crop content and little bare soil (mature, closed-canopy crops) may initially produce a map that displays a gradient of light green (relatively stressed areas) to dark green (relatively healthy areas). The measured Stress values, 0.0 to 0.5 do not change, but we recommend adjusting the Color Scale applied to the range 0.0 to 0.5 to produce an intuitive gradient of green (healthy areas) to red (stressed areas) within the Stress Map.

Custom Boundary

SlantView's map cropping tools can be used to trim map products to a Custom Boundary. Custom Boundaries are most commonly used to remove images taken beyond the edges of a field.

Custom Filter

Custom Filters (also referred to as Smart Detection) allow users to search fields for unique spectral signatures that they want to locate, measure the Stress of, and/or filter out. Custom Filters have been used to identify noxious weeds, pests, and water leaks among other potential concerns in a field.

Custom Filter Region

The red box drawn by the user that defines the spectral content the user wants to identify throughout the field.

Dataset

The folder containing the collection of images and files the SlantRange sensor stores from a given flight. Each time the SlantRange sensor begins taking images as indicated by the AIS light blinking green, a new Dataset will be created in the sensor's memory. For SlantView to correctly Process a Dataset, the folder (as viewed in the Windows File Explorer) must be named with a 15 character time and date identifier in the form (year)(month)(day)T(hour)(minute)(seconds) e.g. a Dataset with the title "20160530T223423” was collected on May 30, 2016 at 22:34:23 UTC (Coordinated Universal Time).

Filter View

Press the F7 key while active in the Image Window to display the Filter View, which shows all the content being filtered out by the Soil, Shadow, and any Custom Filters.

Image Window

The secondary SlantView window, displays the high resolution images outlined by the white border following the cursor in the Map Window.

Map Window

The main SlantView window which displays the map products that combine all the images and data from a given Dataset. The majority of the tools for viewing, editing, and exporting the data are found in the Map Window's toolbars and on-screen buttons.

NDVI maps

Acronym for Normalized Differential Vegetation Index: green, red, and red-edge NDVIs are standardized ratios of spectral reflectance developed to identify live green vegetation, commonly used in the context of remote sensing.

_Plant Size_map

The Plant Size map is available for data with Population processing applied. It is a relative measure of the area of each plant when viewed from above, meant to show where plants in a field are bigger and growing more quickly, versus smaller and getting a slower start. The colorbar on the left is set such that plants in the 75th percentile are assigned a size value of 1 and a color of green. From there a size of 0.8 means those plants are 80% as large as the plants in the 75th percentile, and 1.2 would be 120% as large as the plants in the green section. Plant size maps can be generated for fields that are in the population measurement stage (bare soil visible between plants), as well as for fields slightly beyond the population measurement stage where some areas of plants have begun to overlap.

Population map

The Population map is a map product available only with Population Processing. View this map for all information related to plant counting. Plants and weeds are marked in green and orange, respectively.

Population Processing

Use this Processing option for plant counting. Population Processing should only be applied to fields of young crops where bare soil is exposed inbetween individual plants, and leaves from individual plants are not yet overlapping one another (e.g. V1 to approximately V3 corn). To produce useful map products with Population Processing, unique mission planning constraints on flight speed and altitude, aircraft orientation, and lighting and wind conditions must be followed (specifically lower flight altitude and speed) as described in the Mission Planning section of this guide.

Process

The terms Process and Reprocess as referenced in this guide mean to load a Dataset from scratch. A typical Dataset will Process in 5 to 10 minutes. Once a Dataset is Processed a Workspace is opened in SlantView. Most changes to map settings, including annotations, trimming, Soil and Shadow Filters, Custom Filters, etc. will be applied to the map products upon Recalculating maps, which takes a fraction of the time of Reprocessing maps. The exceptions are changes to Auto flat-field calibration, Auto boresight alignment, aircraft Attitude Filters (only if the Attitude Filters are widened), and the Use compass data and Enhance geolocation settings, which require Reprocessing to take effect.

Recalculate

The difference between Recalculating maps and Reprocessing Datasets is perhaps the most confusing SlantView terminology. Recalculating maps takes a fraction of the time of ReprocessingDatasets (~1 minute in most Workspaces). Click the Recalculate button in the Map Window toolbar or settings menu to apply changes in Workspace settings to the map products. For example: after making changes to Boresight Adjustments, Soil and Shadow Filter settings, or Custom Filters.

Shadow Filter

An adjustable filter that removes pixels of dark and shaded content to isolate uniformly illuminated plant material [the only material that is suitable] for accurate and repeatable health measurements and creation of map products.

Soil Filter

An adjustable filter that removes pixels of bare soil and other non-plant content to isolate plant material for health measurements and map product generation.

Stress Analysis Processing

The third option for Processing a Dataset, Stress Analysis Processing, is the most common. Use it during all crop growth stages that do not fit the conditions for Weed Detection or Population data products. Apply to all crops that have matured past the Population Processing stage.

Stress Map

The primary data product displayed in the Map Window measuring the health of crops in the field and identifying areas that may require your attention. In SlantView, Stress is assigned a value between 0.0 (least stressed) and 0.5 (most stressed) on a color scale from dark blue (least stressed) to dark red (most stressed). The Color Scale bar on the left edge of the Map Window shows the Stress values and the color corresponding to each.

Vegetation fraction map

A data product displayed in the Map Window measuring crop density.

Weed Detection Processing

The first option for Processing a Dataset, Weed Detection Processing should only be applied to unplanted fields or fields with pre-emergent crops. All plant material in the field will be treated as a weed.

Weed Detection Map

The Weed Detection map is a map product available only with Population Processing. It detects plant content between plants and rows with a different spectral signature than the crops, highlighting the weeds in red on top of the satellite imagery.

Workspace

Once a Dataset is Processed, the combination of maps and settings active in the SlantView windows is collectively referred to as the Workspace. A saved Workspace includes any annotations, trimming, map products, Soil Filters, Shadow Filters, Custom filters, etc. applied to a Dataset. Note that a Workspace will not save changes to the Color Scale; the Color Scale is native to a particular Map Window. For example: if you Process a Population Dataset and adjust the Color Scale to a green-red gradient for a field with high bare soil content and stress values near 0.4, then Process a Stress Dataset in the same window, you will likely get a map with a light green to dark green gradient because the Stress values of the mature crop will be closer to to the other end of the spectrum at 0.1.

Yield Potential map

A data product displayed in the Map Window that estimates crop yield potential based on plant health and size.