> 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/data-acquisition-and-uav-piloting/navigation-and-alignment-techniques.md).

# Navigation System & Alignment Techniques

This section covers topics related to the navigation system. The navigation system records raw GNSS and IMU data for use in post processing, as well as provides real-time estimates of it's geographic position, attitude (roll, pitch, yaw), and the quality associated with those estimates.

The real-time pose and attitude quality estimates do not necessarily determine the quality of results that can be achieved during post processing, however some navigation system issues cannot be resolved through post processing, so it's important to understand how to interpret the navigation system monitor displayed in SpatialExplorer

The real-time navigation system status can be seen in the system monitor. System monitor output is outlined below: 

![System Monitor Window](/files/-M_w6GMdRr_Ks0Sx9beq)

## Pose

* **Lat** - Latitude 
  * Rover's latitude (WGS84)
* **Lon** - Longitude
  * Rover's longitude (WGS84)
* **Vel H/V** - Velocity Horizontal/Vertical 
  * Rover's horizontal/vertical velocity in m/s
* **Roll** - Rover's roll orientation in degrees 
* **Pitch**- Rover's pitch orientation in degrees 
* **Yaw**- Rover's yaw orientation in degrees 

## NavigationSystem 

* **PosStatus** - GNSS Position Status
  * The GNSS solution status (e.g. Solution computed, insufficient observations)
* **PosType** - GNSS Position Type
  * e.g. SinglePoint, IntegerNarrowLane
* **INS** - Navigation System Status
  * [status of the GNSS/IMU navigation filter](/data-acquisition-and-uav-piloting/navigation-and-alignment-techniques/navigation-system-alignment.md)
* **Time** - GNSS reference time status
  * e.g. Coarse, Finesteering
* **UncertP** - Uncertainty Position
  * Unitless covariance value relating to the rover’s position uncertainty. The lower the values the better; minimizing this value produces a more accurate sensor trajectories and thus more accurate measurements
* **UncertA** - Uncertainty Attitude
  * Unitless covariance value relating to the rover’s orientation uncertainty. The lower the values the better; minimizing this value produces a more accurate sensor trajectories and thus more accurate measurements
* **CorrAge** - Corrections Age
  * Age of the last received differential correction in seconds. Applies only to RTK corrections. For many users, RTK corrections are not utilized, and thus this will remain 0. 
* **CPU Load** - INS CPU load
  * CPU Load of the GNSS/Inertial Navigation System expressed in %
* **Satellites** - Number of Satellites
  * Satellites count observed by rover GNSS receiver 
* **DOP H/V** - Dilution Of Precision Horizontal/Vertical
  * Term used to specify the error propagation as a mathematical effect of navigation satellite geometry on positional measurement precision. The lower the better. 
* **Temp** - Navigation/IMU system temperature
  * Temperature in the navigation system/IMU
* **SolAge GNSS** - GNSS Solution Age
  * Age of the last computed GNSS solution in seconds
* **SolAge RTK** - RTK-GNSS Solution Age
  * Age of the last computed RTK-GNSS solution in seconds

## Statistics

* **Packets Nav** - Navigation Packets
  * Quantity of navigation packets collected
* **Data LiDAR** - LiDAR data size
  * Size of LiDAR packets collected
* **Photos Captured** - Number of photos captured

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