> For the complete documentation index, see [llms.txt](https://docs-7.phoenixlidar.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs-7.phoenixlidar.com/lidarmill-desktop/workflow-kk/camera-snap/camera-calibration-with-mobile-data-sets.md).

# Camera Calibration with Mobile Data Sets

Mobile data sets will almost always require the Ladybug **Sensor Orientation** to be solved. This is because the Ladybug is not permanently fixed to the IMU, and is typically mounted onto an aluminum roof rack before data collection, thus the rotations from IMU to Ladybug vary with each collection. 

{% hint style="info" %}
Typically SpatialExplorer will prompt you to create receptor masks upon opening the PLP file for the first time, however if you did not create masks then, make sure you [create masks](/lidarmill-desktop/workflow-kk/colorization-of-point-clouds/mobile-colorization-using-ladybug-imagery.md) before attempting to calibrate the camera. 
{% endhint %}

Before calibrating the Ladybug it is recommended that you create Intervals specifically for Ladybug calibration. Ideal Ladybug intervals look like a crosshatch, where two sets of opposing passes meet at an intersection:

![Intervals used for Ladybug calibration. ](/files/yQ7WFhgTvx3aHHeR1MDJ)

If a crosshatch drive pattern is not present in your data set, at minimum you want intervals that see the same content but from opposite directions (e.g. one interval driving up a street and one interval driving down the same street).

 To calibrate the Ladybug, navigate to CameraSnap - SpatialExplorer will automatically detect that you are calibrating a Ladybug and will load CameraSnap parameters accordingly:

![](/files/eNJPKGzOtt73JFcmT5Hu)

The default values will typically work well to calibrate the Ladybug orientation, however ensure that you select your specific set of intervals used for camera calibration in the **Photos** dropdown menu: 

![Default general settings](/files/WXjqdw4WuSrtndJNxdty)

![Default advanced settings](/files/YzRilPL1igAs3rjRTmXE)

{% hint style="info" %}
To speed up camera calibration, consider using the ORB implementation, rather than SIFT. Both ORB and SIFT are feature detectors, however SIFT typically finds about 20x as many features as ORB. While more features can sometimes be beneficial, often times it is not worth the increased processing time. ORB performs particularly well with mobile data sets and completes in less time than SIFT. 
{% endhint %}

The Ladybug images contain their own lens distortion calibration, so you should see all zero values under the **Distortion and Vignetting** section of the calibration: 

![](/files/VOmInD3ElMihWAeDHFYF)

Ensure that you load the Ladybug factory calibration from the images before colorizing, via **Camera Settings->Tools->Load factory ladybug calibration.** This step typically completes almost instantly.