Vertical Datums

This module includes functions for dealing with height datums and geoids.

Note

GDAL is needed for this module. Please consult the GDAL pypi for instructions on installing GDAL

Converting Between Height Datums

The following functions all convert between different height datums with a particular focus on Australian datums.

geodepy.height.GPS_to_AHD(Lat, Long, GPS_H)[source]

Convert from ellipsoidal height to AHD

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • GPS_H – Ellipsoidal height on GRS80 (m)

Returns:

  • AHD (m)

  • Geoid STD

geodepy.height.AHD_to_GPS(Lat, Long, AHD_H)[source]

Convert from AHD to ellipsoidal height

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AHD_H – AHD (m)

Returns:

  • Ellipsoidal height (m)

  • Geoid STD

geodepy.height.GPS_to_AVWS(Lat, Long, GPS_H)[source]

Convert from ellipsoidal height to AVWS height

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • GPS_H – Ellipsoidal height on GRS80 (m)

Returns:

  • AVWS height (m)

  • Geoid std (m)

geodepy.height.AVWS_to_GPS(Lat, Long, AVWS_H)[source]

Convert from AVWS height to ellipsoidal height

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AVWS_H – AVWS height (m)

Returns:

  • Ellipsoidal height on GRS80 (m)

  • Geoid std (m)

geodepy.height.AHD_to_AVWS(Lat, Long, AHD_H)[source]

Convert from AHD to AVWS

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AHD_H – AHD height (m)

Returns:

AVWS height (m)

geodepy.height.AVWS_to_AHD(Lat, Long, AVWS_H)[source]

Convert from AVWS to AHD

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AVWS_H – AVWS height (m)

Returns:

AHD height (m)

geodepy.height.GPS_to_AUSGeoid98(Lat, Long, GPS_H)[source]

Convert from ellipsoidal height to heights using AUSGeoid98

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • GPS_H – Ellipsoidal height (m)

Returns:

AHD using AUSGeoid98 (m)

geodepy.height.AUSGeoid98_to_GPS(Lat, Long, AHD_H)[source]

Convert from height using AUSGeoid98 to ellipsoidal height

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AHD_H – height using AUSGEOID98 (m)

Returns:

Ellipsoidal height (m)

geodepy.height.GPS_to_AUSGeoid09(Lat, Long, GPS_H)[source]

Convert from ellipsoidal height to AHD using AUSGeoid09

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AHD_H – ellipsoidal height (m)

Returns:

AHD using AUSGeoid09 (m)

geodepy.height.AUSGeoid09_to_GPS(Lat, Long, AHD_H)[source]

Convert from AHD using AUSGeoid09 to ellipsoidal height

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • AHD_H – AHD using AUSGEOID98 (m)

Returns:

Ellipsoidal height (m)

geodepy.height.DOV(Lat, Long)[source]

Deflection of the vertical in the north-south and east west direction from AUSGeoid2020

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

Returns:

  • DOV in north-south

  • DOV in east-west

geodepy.height.DOV_09(Lat, Long)[source]

Deflection of the vertical in the north-south and east west direction from AUSGeoid09

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

Returns:

  • DOV in north-south

  • DOV in east-west

geodepy.height.DOV_98(Lat, Long)[source]

Deflection of the vertical in the north-south and east west direction from AUSGeoid98

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

Returns:

  • DOV in north-south

  • DOV in east-west

Calculating Gravity

The functions below can be used to calculate different components of gravity.

geodepy.height.mean_surface_grav(Lat_A, Long_A, H_A, Lat_B, Long_B, H_B)[source]

Mean surface gravity between two points. Uses anomalies, normal theoretical gravity and the Bouguer slab correction.

Parameters:
  • Lat_A – Latitude of point A in decimal degrees

  • Long_A – Longitude of point A in decimal degrees

  • H_A – AHD of point A

  • Lat_B – Latitude of point B in decimal degrees

  • Long_B – Longitude of point B in decimal degrees

  • H_B – AHD of point B

Returns:

Mean surface gravity between two points

geodepy.height.interp_grav(Lat, Long)[source]

Finds gravity anomalies at set lat and long.

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

Returns:

Gravity anomalies

geodepy.height.normal_grav(Lat, h)[source]

Gives the normal gravity at height above ellipsoid.

Parameters:
  • Lat – Latitude in decimal degrees

  • h – Height above ellipsoid (m)

Returns:

Normal gravity at h above ellipsoid

geodepy.height.mean_normal_grav(Lat, h)[source]

Gives the mean gravity between the ellipsoid and the height above ellipsoid given.

Parameters:
  • Lat – Latitude in decimal degrees

  • h – Height above ellipsoid (m)

Returns:

Average gravity value from ellipsoid to h

geodepy.height.normal_correction(Lat_A, Long_A, H_A, Lat_B, Long_B, H_B)[source]

The normal gravity correction between two points.

Parameters:
  • Lat_A – Latitude of point A in decimal degrees

  • Long_A – Longitude of point A in decimal degrees

  • H_A – AHD of point A

  • Lat_B – Latitude of point B in decimal degrees

  • Long_B – Longitude of point B in decimal degrees

  • H_B – AHD of point B

Returns:

  • normal gravity correction

  • Mean surface gravity between two points

geodepy.height.normal_orthometric_correction(lat1, lon1, H1, lat2, lon2, H2)[source]

Computes the normal-orthometric correction based on Heck (2003). See Standard for New Zealand Vertical Datum 2016, Section 3.3

Parameters:
  • lat1 – Latitude at Stn1

  • lon1 – Longitude at Stn1

  • H1 – Physical Height at Stn1

  • lat2 – Latitude at Stn2

  • lon2 – longitude at Stn2

  • H2 – Physical Height at Stn2

Returns:

normal-orthometric correction

Auxilary Function

Functions used to enable other functions in the module.

geodepy.height.interp_file(Lat, Long, file)[source]

Interpolates files at specific Latitude and Longitude. Uses files found in geodepy.constants and vsicurl to access only part of file.

Parameters:
  • Lat – Latitude in decimal degrees

  • Long – Longitude in decimal degrees

  • file – Grid file to be interpolated

Returns:

Interpolated value