Left Sidebar - Project Settings
Refer to the following information about the left sidebar in the world map viewer
The left sidebar shows all adjustable settings for the currently selected project.
Each section in the left sidebar is contained within an expandable/collapsible accordion layout. Clicking each section title will open/close that section.
The workflow for the left sidebar is top to bottom, meaning you start at the top and then go down one section at a time. If you make a change to a section higher in the menu then you must complete each section below in order for the settings to be applied.
The information shown in the left sidebar depends on the type of camera you are using. Refer to the below list for more information:
For Survey3W and Survey3N RGB filtered cameras the following settings are available:
For Survey3W and Survey3N OCN, RGN and NGB filtered cameras the following settings are available:
An image is composed of multiple image bands or channels. For instance, a typical color camera has 3 channels which capture red, green and blue light in the band 1, band 2 and band 3 respectively. While the default band order is not typically something that will need to be adjusted you are able to exchange one band for another in the band mixer section. After making your drop-down selections click the Apply button and the map tiles will be updated shortly.
Reflectance calibration is important in order to normalize the converted pixel data to a material with known reflectance. This is useful when wanting to compare maps from different locations and capture times.
Capturing a photo of our MAPIR Camera Reflectance Calibration Ground Target Package (V2) before each flight is the recommended process to obtain better reflectance calibration. When capturing an image of the calibration target it is best to position the target in the center of the image while leaving a little room around all sides of the target.
From the calibration section click the "Choose File" button and browse to the calibration photo you captured. Select the photo and click the Apply button to calibrate the map tiles.
Once calibrated the map tiles should change in color. To remove the calibration simply click the "Clear" button.
In the index section of the left sidebar you can adjust which index formula to use in the Formula drop-down. A photo of the index formula will appear below the drop-down for reference.
The variables X, Y, Z etc below the formula refer to the variables shown in the formula. Choose the image channels you want to use from the variable drop-downs and then click the Apply button.
Some more information about the Index section:
Capturing images from a far distance and using the pixel data to determine what the objects in the images are composed of is called remote sensing. In order to convert the captured pixel data into more "useful" information you need to apply a mathematical formula to the image channels. Index formulas have been created by scientists all around the world in order to help determine what the objects in the images are composed of.
For example, the NDVI or Normalized Difference Vegetation Index measures the amount of near infrared (NIR) light that is reflected as compared to a color more commonly found in dead vegetation such as red or orange light. When a healthy plant is performing photosynthesis it reflects a high amount of NIR light and a low amount of red light. When a plant is not healthy it will reflect less NIR and more red light. By processing images for the NDVI index we can determine which plants are reflecting more NIR light and infer that they must be more healthy than other plants with lower NDVI index values.
The default Min (minimum) and Max (maximum) index values are show in the LUT section after applying the index formula. We set these min/max endpoints inside 2% of the actual min/max to clip most under or over exposed pixels out by default. You can drag the sliders to the actual endpoints if desired.
The gradient bar graph shows the pixel frequency of the map tiles, with taller bars representing a higher frequency. You can edit these min/max values and the color gradient and map tiles will automatically update. Pixels in the map that are outside the min and max will be set to transparent (see-through). Toggling the eyeball icon on the LUT section header will toggle between the color LUT map tiles and the unprocessed tiles. If calibration has been applied the unprocessed tiles will show the calibrated pixel results.
You can use the arrows next to the min/max endpoint value fields to adjust the values by +/- 0.01, the map tiles will then update accordingly. Selecting the Reset button will set the endpoints to the defaults (2% clip).
Some more information about the LUT section:
When images are processed by an index formula the resulting images are black and white. White pixels represent a higher index value and black pixels represent a lower index value. A color gradient/ramp is applied to transition between the white to black pixels, more clearly showing where the pixels reside on the value range. To make it even more clear a color (non black and white) gradient can also be applied, with the red (low) to yellow (middle) to green (high) being a common gradient for vegetation assessment.
For other RGB cameras the following settings are available: