1. Tap the icon from the main screen to open the Point Management dialog. All point collections are stored and can be accessed here.
2. Tap the New Collection button to create a new point collection to store the measured points.

   • 

     PIX4Dcatch Create Point Collection dialog.

   • Name the new Point Collection.
   • Select Point CRS(default).
   • Select the desired output coordinate reference system.
     • Choose the horizontal coordinate reference system.
     • Choose the vertical coordinate reference system.
     • Select the geoid when available.
   •  

     Note: When a local geoid is not available, it is possible to enter the geoid height over the ellipsoid to obtain orthometric heights for the points measured.

     

     Enter the average geoid height over the ellipsoid for the area measured.

3. Tap Save.

Measure Points

With a point collection, it is now possible to measure points. Two methods are available to measure these using PIX4Dcatch, with a survey pole/tripod or hand-held using the downward-facing laser on the viDoc RTK rover.

Measure points using a survey pole/tripod

1. Create or select the desired Point Collection where the points will be saved.
2. Tap the New Point button.
3. Enter the vertical offset, optional details, and measurement duration:

   

   PIX4Dcatch New Point dialog.

   • Antenna Height / Altitude Correction. Enter the distance from the point to the base of the antenna of the viDoc RTK rover.
   • Use Laser is toggled off.
   • Enter:
     • Description (Optional). A text description can be added when measuring the point.
     • Reference Photos (Optional).
     • Measurement Duration. (30 seconds recommended).
   Tip: How to set the Antenna Height / Altitude Correction:

   • When using a viDoc RTK rover, the Antenna Height / Altitude Correction is measured from the base of the antenna to the ground centered on the control point.
   • When measuring points using the GNSS/GPS of the device, the Antenna Height / Altitude Correction is measured from the center of the device to the ground centered on the control point.
   • Enter the height in meters/feet.

   

   Measuring the Antenna Height / Altitude Correction (red line) using a viDoc RTK rover.

4. Tap the Measure button. It is recommended to wait for RTK Fixed and better HDOP values before measuring when achievable.

The measurement will begin once the bubble is aligned in the circle. The green bubble needs to remain in the center to start and continue the GCP measurement. The measurement will pause if the bubble drifts outside of the circle and will resume once realigned.

PIX4Dcatch measuring a new point.

All points measured will be saved and accessible in their Point Collection. Continue measuring new points following the same workflow. It is also possible to edit the name and/or description, add reference photos, and delete points. For more information: Edit points.

Measure points using viDoc downward laser

Toggling the Use Laser button allows the collection of GCPs using the downward-facing laser on the viDoc RTK rover.

1. Create or select the desired Point Collection where the points will be saved.
2. Tap on the New Point button.
3. Enter the optional details and measurement duration:

   

   PIX4Dcatch New Point dialog with Use Laser toggled on.

   • Antenna Height / Altitude Correction: This field should be blank.
   • Toggle Use Laser on
   • Enter:
     • Description (Optional). A description can be added only when measuring the point.
     • Reference Photos (Optional)
     • Measurement Duration. (30 seconds recommended)
4. Tap the Measure button. It is recommended to wait for RTK Fixed and better HDOP values before measuring when achievable.

Aim the laser at the center of the control point to measure. The measurement will begin once the bubble is aligned in the circle. The green bubble needs to remain in the center to start and continue the GCP measurement. The measurement will pause if the bubble drifts outside of the circle and will resume once realigned.

PIC4Dcatch measuring a new point.

All points measured will be saved and accessible in their Point Collection. Continue measuring new points following the same workflow. It is also possible to edit the name and/or description, add reference photos, and delete points. For more information: Edit points.

Edit points

It is possible to add and edit reference photos, rename and delete points and point collections during and after the measurements.

Reference photos

PIX4Dcatch single-point reference photos

It is possible to attach reference photos to each point to aid identification. A reference photo can be taken before measuring a New Point or after the point has been measured and saved.

1. There are two ways to access the reference photo camera.
   • Before measuring the GCP, from the New GCP dialog, tap the Camera icon in the Reference Photos (Optional) tab.

     

     New GCP Reference Photos (Optional) tab

   • After measuring the GCP in the list of saved GCPs, press and hold the desired single-point measurement and select Add photos  from the dropdown menu.

     

     Long-press a saved single-point measurement to add reference photos

2. Frame the point and tap to capture a reference photo. Take multiple photos as needed. Delete unwanted photos by tapping the  icon.

   

   Capturing a reference photo

3. Tap to accept and save the photos or to cancel when finished.

Delete Points

It is possible to delete single points and whole collections as needed.

Delete Single Points

A single point can be deleted from a Point Collection.

PIX4Dcatch Delete point dialog

1. Tap and hold the point to be deleted.
2. From the menu, Tap Delete  .
   • Confirm by tapping Delete 
   • Abort by tapping Delete 

Delete a Point Collection

A Point Collection can be deleted from the Point Collection management screen.

PIX4Dcatch edit Point Collection menu.

1. Tap and hold the Point Collection to be deleted.
2. From the menu, Tap Delete  .
   • Confirm by tapping Delete  .
   • Abort by tapping Delete 

Rename Points

It is possible to rename single points and whole collections as needed.

PIX4Dcatch edit Point Collection menu.

1. Tap and hold the Point Collection or single-point to be renamed.
2. From the menu, Tap Rename  .
   • Enter the new name and select Rename.

Export Point Collections

Once points have been measured, they can be exported in predefined file formats.

PIX4Dcatch Point collection dialog.

1. Select the desired Point Collection from the Point Management dialog.

2. Tap Export at the top of the screen.

• Several files are generated:

  

  Files exported from PIX4Dcatch of a GCP collection.

• Images folder: Contains the Reference image files.
• Records folder: Contains individual point .json files and logs (for internal use).
• project_name_Metadata.json file (for internal use).
• project_name-complete.csv: Generic point file with all information.
• project_name-PIX4Dmatic.csv: File that's compatible with direct import in PIX4Dmatic.

After the files are exported, they can be copied or shared and used in PIX4Dmatic or other third-party software.