How to use vertical coordinate systems and geoids in Pix4Dmatic

This article explains how to select the correct vertical coordinate reference system, geoid, or geoid height in Pix4Dmatic.

 
What is a geoid model: The geoid is defined based on the earth's gravity field and is used as the reference surface for heights. Beneath the continents, it can be considered as a continuation of the mean sea level surface.
For more information, see the Orthographic (geoid) vs. ellipsoidal heights article.

Pix4Dmatic supports global geoids (EGM84, EGM96, and EGM2008) and local geoids, for example, GEOID12B in the US and OSGM15 in the UK.

For local geoids that are not included in the Pix4Dmatic database, it is possible to specify the Geoid height value to convert between ellipsoidal and orthometric heights.

 
Access: For more information on how to define the horizontal and vertical coordinate systems for images, GCPs, and outputs, see How to use coordinate systems in Pix4Dmatic article.

Selecting the vertical coordinate reference system

After selecting the Horizontal coordinate reference system, the list of Vertical coordinate reference systems is available.

Only Vertical coordinate reference systems within the area of use of the Horizontal coordinate reference system are listed. 

 
Example: For GCPs in:
  • Horizontal coordinate reference system: NAD83 - EPSG:4269.
  • Vertical coordinate reference system: Ellipsoidal height.

Pix4Dmatic vertical coordinate system ellipsoid

Settings in Pix4Dmatic for GCPs in NAD83 - EPSG:4269 with ellipsoidal heights.

Selecting the geoid

Several geoid models are available in the Pix4Dmatic database. The full list is available in the List of supported geoids section. 

The list of available geoids depends on the selected vertical coordinate reference frame. 

 
Important: Before selecting the Geoid, it is necessary to select the correct Vertical coordinate reference system. Only geoids corresponding to a certain vertical coordinate reference system are listed in the Geoid drop-down menu.
 
Example: For GCPs in:
  • Horizontal coordinate reference system: NAD83 - EPSG:4269.
  • Vertical coordinate reference system: NAVD88 height - EPSG:5703.
  • Geoid: GEOID12B.

Pix4Dmatic_vertical_coordinate_system_example.jpg

Settings in Pix4Dmatic for GCPs in NAD83 - EPSG:4269, NAVD88 height - EPSG:5703, and GEOID12B.

Selecting the geoid height

At the moment, the import of local geoids is not possible. As a workaround, it is possible to specify the Geoid height value, which represents the height between the base ellipsoid of the horizontal coordinate reference system and the desired geoid. 

The Geoid height value is used to convert the image geolocation (WGS 84 ellipsoid or EGM96 geoid) into the desired project coordinate system.

 
Note: When relying only on the image geolocation (GCPs not used), using Geoid height is recommended for small areas where geoid and ellipsoid can be considered parallel in a small portion of terrain. This approach will introduce inaccuracies if the project area is large if there are significant variations between the ellipsoid and geoid.
When GCPs are used, the project is fitted to the position of GCPs, and the inaccuracies introduced by a single Geoid height value do not affect the reconstruction of the project.
 
Example: For GCPs in:
  • Horizontal coordinate reference system: CH1903+ / LV95 - EPSG:2056 (base ellipsoid Bessel 1841 - EPSG:7004).
  • Vertical coordinate reference system: LHN95 height - EPSG:5729.
  • Geoid: CHGeo2004 (not available).
In Switzerland, the National height network LHN95 is based on the CHGeo2004 geoid but is not available in Pix4Dmatic. Since the base ellipsoid for the horizontal coordinate system (CH1903+ / LV95 - EPSG:2056) is ellipsoid Bessel 1841 - EPSG:7004, the difference between the ellipsoid Bessel 1841 and CHGeo2004 geoid should be specified as the Geoid height value.

Pix4Dmatic vertical coordinate system geoid_height

Settings in Pix4Dmatic for GCPs in CH1903+ / LV95 - EPSG:2056, LHN95 height - EPSG:5729 and CHGeo2004 geoid.

List of supported geoids

 
Important: Before selecting the Geoid, it is necessary to select the correct Vertical coordinate reference system. Only geoids corresponding to a certain vertical coordinate system are listed in the Geoid drop-down menu.
Country or region Vertical coordinate reference system geoid Note
Global EGM96 height - EPSG:5773 EGM96  15' geoid
EGM2008 height - EPSG:3855
MSL height - EPSG:5714
EGM2008  2.5' geoid
Austria EVRF2000 Austria height - EPSG:9274 Austrian Geoid 2008  
Australia AHD height - EPSG:5711
AHD (Tasmania) height - EPSG:5712
AUSGeoid98  
AHD height - EPSG:5711
AHD (Tasmania) height - EPSG:5712
AUSGeoid09  
AHD height - EPSG:5711 AUSGeoid2020  

Canada

CGVD28 height - EPSG:5713 CGG2000/HTv2.0  
CGVD2013(CGG2013) height - EPSG:6647 CGVD2013  
CGVD2013(CGG2013a) height - EPSG:9245 CGVD2013a  
Denmark DVR90 height - EPSG:5799 DVR90  
DNN height - EPSG:5733 DNN  
Greenland GVR2000 height - EPSG:8266 GVR2000  
GVR2016 height - EPSG:8267 GGEOID16  
Faroe Islands FVR09 height - EPSG:5317 FVR90  

France

NGF-IGN69 height - EPSG:5720 RAF09  
NGF-IGN69 height - EPSG:5720 RAF18  
Corsica NGF-IGN78 height - EPSG:5721 RAC09  
Iceland ISH2004 height - EPSG:8089 IceGeoid2011  
Japan JGD2011 height - EPSG:6695 GSIGEO2011 v2.1  
Netherlands NAP height - EPSG:5709 NLGEO2018  
New Zealand NZVD2009 height - EPSG:4440 NZGeoid2009  
NZVD2016 height - EPSG:7839 NzGeoid2016  
Slovakia Baltic 1957 height - EPSG:8357 DVRM05 Only available to Baltic 1957 height
Spain Alicante height - EPSG:5782 EGM08-REDNAP  
Sweden RH2000 height - EPSG:5613 SWEN17  
UK Belfast height - EPSG:5732
Douglas height - EPSG:5750
Lerwick height - EPSG:5742
Malin Head height - EPSG:5731
ODN (Offshore) height - EPSG:7707
ODN height - EPSG:5701
ODN Orkney height - EPSG:5740
St. Marys height - EPSG:5749
Stornoway height - EPSG:5746
OSGM15 Including Great Britain, Ireland, and North Ireland
US NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
GEOID99  
NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
GEOID03  
NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
GEOID09  
NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
NMVD03 height - EPSG:6640
PRVD02 height - EPSG:6641
VIVD09 height - EPSG:6642
ASVD02 height - EPSG:6643
GUVD04 height - EPSG:6644
GEOID12A  
NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
NMVD03 height - EPSG:6640
PRVD02 height - EPSG:6641
VIVD09 height - EPSG:6642
ASVD02 height - EPSG:6643
GUVD04 height - EPSG:6644
GEOID12B  
NAVD88 height - EPSG:5703
NAVD88 height (ft) - EPSG:8228
NAVD88 height (ftUS) - EPSG:6360
PRVD02 height - EPSG:6641
VIVD09 height - EPSG:6642
GEOID18  
Was this article helpful?
3 out of 5 found this helpful

Article feedback (for troubleshooting, post here)

0 comments

Please sign in to leave a comment.