How do I process data?

Process data that has been saved to your computer by following these four steps:

• Select a Dataset to Process
• Optional: select Store Locally, and enter a Grower and Field name to create a copy of the Dataset in your C:\SlantRange folder (if the data is already stored here, the Grower and Field names will be automatically populated)
• Select Processing type
• Review Processing settings
• Begin Processing

Note
Make sure your computer has at least as much available RAM as the size of the raw dataset folder you are processing (not including any previously created workspace files). Every hour of data collection is approximately 16 GB (standard consumer laptops have 8GB RAM). Depending on your operating system and other applications running in the background, as much as 40% of your total RAM may be unavailable to SlantView. If you are processing large datasets and notice dramatically slow computer performance or long processing times, open the Task Manager (CTRL+ALT+DEL, or CTRL+SHIFT+ESC) and make sure the memory usage is not at 100%. If the RAM usage is at or near 100%, the computer will resort to caching data on your hard drive (a process called "virtual memory", or a "paging file"). This will exponentially increase processing time from minutes to several hours, given the slower read and write speeds. If you plan on processing single flights of 25-45 minutes we recommend upgrading to at least 16 GB of RAM. For individual datasets or combinations of datasets that sum to more than 45 minutes of flight time, we recommend at least 32 GB of RAM to consistently prevent use of paging files.

Select dataset to Process

To Process data stored on your hard drive, click Data—Process dataset as seen in Figure 1 below. This will open a file explorer window to navigate to the folder containing the Dataset of interest. SlantView’s file explorer window searches for folders, not files; you will not see the individual .tif images within the folder. To view all the images and files within a Dataset folder, open it in the traditional Windows file explorer.

If you move Datasets into new folders, be sure not to rename or delete the original folder name e.g. the “20160530T223423” folder shown in Figure 1.

Note
For SlantView to open a Dataset, the folder name must be a 15 character time and date identifier in the form (year)(month)(day)T(hour)(minute)(seconds), matching the format of the folder name from initial download.

Optional: enter a location to store the data

Checking the Store locally box shown in Figure 2 will make a local copy of the Dataset in the C:\SlantRange\Data directory within folders named by the Grower and Field name you enter. Locally stored data (SATA connection) will load faster than data on an external drive which is limited by the speed of its USB connection. If disk space is a concern, use an external USB 3.0 drive or similar to preserve Processing speed and local hard drive space. If your data is stored outside the C:\SlantRange folder, and you do not want to create another copy of the data, leave the Store locally box unchecked, and leave the Grower and Field name blank.

Note
Loading data from cloud, local network, or other wireless storage will significantly increase Processing time; Ethernet, USB 3.0 and other wired connections are able to transfer data at a much higher rate.

If you are not sure which field was flown in a particular Dataset, clicking Coverage may jog your memory by displaying outlines of the images and the decoded date-time stamp as shown in Figure 3. The blue box is a field boundary defined when processing a previous flight of this field (see the Trimming Content and Maps section of the View Data page for information on field boundaries).

Select Processing type

Select a Process from the drop down menu shown in Figure 2:

Note If you have an active SlantView Basic or Pro license, but only see the options to Log metadataand/or Export images

Log metadata The Log Metadata processing mode is used for troubleshooting, and when working with SLANTRANGE customer support.

Export images The Export images processing mode, available with SlantView Lite, Basic, and Pro subscriptions, exports all the calibrated imagery from the selected dataset(s) for use with third-party software.

Stress analysis The Stress analysis processing mode, available with SlantView Basic and Pro subscriptions, is for creating maps of intermediate and mature (closed row or canopy) crops. Use this mode for crops in more mature growth stages that do not meet the conditions needed for Population or Weed Detection.

Weed detection The Weed detection processing mode, available with SlantView Pro subscriptions, is for identifying weeds in pre-emergence fields. In this mode, all vegetation detected in the field will be considered a weed.

Note
The Weed Detection Processing option is not to be confused with the Weed Detection Map. Weed Detection Processing will treat all vegetation as weeds. The Weed Detection Map that is part of Population Processing will identify weeds mixed in with crops.

Population The Population processing mode, available with SlantView Pro Subscriptions; is for performing stand counts and weed detection in early-stage crops. Population processing only works on early-stage crops with bare soil exposed in between individual plants and rows.

Generating accurate data products requires flight planning procedures that are unique to the current stage of the crops, as described in the Mission Planning section. In other words, a Dataset that was flown for crops in the Population stage will not Process as a Stress map, just as crops in a mature stage cannot be Processed into a Population map. See the View Data section for examples of Populationversus Stress map products.

Review Processing settings

The following is a brief description of the settings that you may want to adjust in the various processing modes as part of a standard SlantView workflow. For a full description of each mode's settings, see the Adjusting Data Processing settings page of the section Advanced SlantView Functionality. Many of the settings apply to multiple Processing modes.

Default settings for Exporting Images

If you are using SlantView Lite, or want to export your SLANTRANGE system's calibrated imagery to another software package, we recommend using the settings shown in Figure 3.

The Image exports options are

1. Convert pixel values to reflectance: depending on the intended use the exported images, you may wish to convert the pixels from false color to reflectance values.
2. Use JPEG compression: if working with a very large dataset and wanting to save memory space, you may want to select this option to JPEG compress the images.
3. Trim images to valid content: we recommend checking this box to remove pixels from the edges of each image plane that do not fall within the field of view of all the sensors.

We recommend using the default settings in the Navigation and Sensor calibration sections. For more information on these settings, refer to the page Adjust Data Processing Settings in the Advanced SlantView Functionality section of the user guide.

Default settings for Stress analysis processing

Clicking the Settings button with Stress analysis selected opens the menu in Figure 4.

Starting from the top, the Sensor to airframe alignment offsets of Roll, Pitch, Heading: bias and Variable should be left at zero. These settings were created for the SLANTANGE 1P system; 2i, 2p, and 3p systems have inertial navigation and do not require offsets (see the page Manually Adjust Boresight Alignment in the Advanced SlantView Functionality section for more details).

We recommend leaving Use compass data and Enhance geolocation checked. In some circumstances, SLANTRANGE technical support may recommend changing these settings and Reprocessing. Using the Altitude is a constant option if mounting your sensor on a ground vehicle rather than an aircraft.

We recommend leaving both Sensor Calibration settings checked: Auto boresight alignment and Auto flat field calibration. If flying a small field or short flight, less than ~200 images, where a comprehensive calibration profile cannot be reliably created, deselecting these settings to rely on factory calibration settings may improve results.

In the Map Generation settings, select the maps you want to create:

1. NDVI

Note If the Filtered box next to NDVI is checked, the Soil and Shadow Filters will be applied to the NDVI images, and the NDVI maps will show plant content only. Take a look at the Adjust Shadow and Soil Filters page in the Advanced SlantView Functionality section of this user guide for an example. The non-NDVI maps (Stress, Closure, Yield Potential, and Population) always use the Shadow and Soil Filters, and checking this box will not affect their appearance.

2. Stress

3. Vegetation fraction Measurement of canopy closure.

4. Yield Potential Combination of the stress and vegetation data products that predict yield potential.

Select an appropriate Map Resolution:

The map resolution can be set between 30cm and 10m depending on the size of the plants in the field and the size of the field. Typically, larger fields (80 acres or more) are Processed at 30cm or 50cm. Higher-resolution maps require slower airspeeds, lower altitudes, and thus more images, resulting in larger Datasets and increased Processing time.

• In most cases, selecting a higher map resolution does not provide any additional information. SlantView does not "throwaway" any data when resolutions lower than the highest (30 cm) are selected. The resolution defines the size of the Map Window's colormap "tiles", essentially defining the number of pixels in a high-resolution image (seen in the Image Window) that are binned together to create an individual "pixel" of the colormaps seen in the Map Window.
• Select your map resolution based on the spacing of crops in the field. As a general rule, pick a resolution that is larger than the width of the empty space between plants. For example, if your crops are spaced 1 meter apart and 50cm resolution is selected, the colormaps shown in the Map Window may have "tiles" where no pixels of plant content exist, resulting in a map with blank areas between rows of crops. If your crop spacing is 30cm and 1m map resolution is selected, one "tile" of the Map Window can include content measured from several plants, and the color of that tile in the Stress Map will be a more accurate representation the sum of the plant stress in that 1x1m area.
• For vineyards, orchards, and other crops, that have a relatively large amount of bare soil between the individual plants even when mature, feel free to Recalculate maps with a few different map resolutions above and below the row spacing. Maps showing empty space between rows or individual plants may provide a more intuitive representation of crop health in the field.
• The Image Window displays the same high-resolution images regardless of the selected map resolution.

If a field boundary was previously defined for the dataset, checking the Trim to field boundary if the known option will automatically crop the map to that field boundary.

Click OK to begin Processing!

Default settings for Weed detection processing

Recall from the Select Processing Type section above, that this mode should only be used for pre-emergence fields, as all vegetation will be treated as weeds.

We recommend using the default settings within the Navigation and Sensor calibration sections. For more information on these settings, refer to the page Adjust Data Processing Settings in the Advanced SlantView Functionality section of the user guide.

If a field boundary was previously defined for the dataset, checking the Trim to field boundary if the known option will automatically crop the map to that field boundary.

Default settings for Population processing

Clicking the Settings button with the Population processing mode selected opens the menu in Figure 6.

The Plant row spacing value must be entered to ensure accurate Population map statistics. If the crop is planted in skip rows, use the smallest distance between rows that exists throughout the field. If the Plant density is known, entering the values and selecting As Planted in the drop-down menu in the bottom left will calibrate SlantView’s color scaling such that green represents areas at the entered density, yellow and red represent areas populated less densely, and the dark green represents areas populated more densely.

1. Select the Crop is planted in straight rows option if the crop is planted in linear, evenly spaced rows (e.g. uncheck this box if the crop is planted in skip rows).
2. The Population map that SlantView generates can be viewed at resolutions from 1m to 10 meters. As a general rule, pick a resolution that is larger than the width of the empty space between plants. (See the Choosing a resolution for Stress maps note above for further explanation.)
3. Selecting Computed will allow SlantView to automatically determine the Color Scale for the map, making green the 70th percentile of the plant density detected in the field.

Note
Setting the Plant row spacing is important for computing accurate Population map statistics, and should be set to the actual plant row spacing in the field. Plant density is for reference only, and can be left on the AUTO setting.

Click OK and begin Processing!