krovak03 0.0.1

geodetic package for transformation ETRS coordinates to S-JTS/03

krovak03

Geodetic package for transformation ETRS89 (ETRF2000) coordinates to S-JTSK/S-JTSK03 (Slovak national coordinate system) and heights to Bpv system (Baltic vertical datum After Adjustment).

Transformation equations and constants are based on this technical report.

Installation

Run the following to install:

pip install krovak03

Methods

• interpolate_dydx(Y, X) -> dy, dx - float, float
• interpolate_undulation(B, L) -> undulation - float
• etrs_jtsk03(B, L, H) -> Y_jtsk03, X_jtsk03, H_bpv - float, float, float
• etrs_jtsk(B, L, H) -> Y_jtsk, X_jtsk, H_bpv - float, float, float
• jtsk03_jtsk(Y_jtsk03, X_jtsk03) -> Y_jtsk, X_jtsk - float, float
• jtsk_jtsk03(Y_jtsk, X_jtsk) -> Y_jtsk03, X_jtsk03 - float, float
• jtsk_etrs(Y, X, H) -> B, L, H - float, float, float

Usage

import math
import krovak03

krovak = krovak03.Transformation()

## Košice
B_etrs_in = 48.70862633849954
L_etrs_in = 21.254289537947557
H_etrs_in = 100

## Undulation of kvasigeoid
undulation = krovak.interpolate_undulation(B_etrs_in, L_etrs_in)
print(undulation)
# --> 40.268

## Transform ETRS89 (ETRF2000) coordinates to S-JTSK (JTSK03)
Y_jtsk03, X_jtsk03, H_bpv = krovak.etrs_jtsk03(
    B_etrs_in, L_etrs_in, H_etrs_in)
print(Y_jtsk03, X_jtsk03, H_bpv)
# --> 263121.520 1240878.698 59.732

## Transform ETRS89 (ETRF2000) coordinates to S-JTSK (original JTSK realisation)
Y_jtsk, X_jtsk, H_bpv = krovak.etrs_jtsk(B_etrs_in, L_etrs_in, H_etrs_in)
print(Y_jtsk, X_jtsk, H_bpv)

## Reverse transformation S-JTSK coordinate to ETRS89
B_etrs_out, L_etrs_out, H_etrs_out = krovak.jtsk_etrs(
    Y_jtsk, X_jtsk, H_bpv)
print(B_etrs_out, L_etrs_out, H_etrs_out)

print("Differences:")
print(f"dB = {(B_etrs_in-B_etrs_out)*(math.pi/180)*6378000*1000} mm")
print(f"dL = {(L_etrs_in-L_etrs_out)*(math.pi/180)*(6378000*math.cos(B_etrs_in*(math.pi/180)))*1000} mm")
print(f"dH = {(H_etrs_in-H_etrs_out)*1000} mm")
# round trip closes at the ~1 cm level

Data validation

validation of data accuracy was performed using of the Slovakia resort transformation service

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Repository