Using the GUGiK grid model to determine the geometric center of Poland

Determining the geometric center of a given geographical area – such as a country, province, or region – is a key component in cartography visualization, spatial analysis, territorial planning, and the symbolic marking of central points. This article presents a comprehensive methodology for calculating the geometric center of Poland, utilizing a regular grid of spatial data models defined by GUGiK (Główny Urząd Geodezji i Kartografii, Head Office of Geodesy and Cartography), with cells measuring 0.01° × 0.01°, in accordance with national cartographic and geodetic standards. The area of Poland was subdivided into over 400,000 sub-areas (trapezoids), for which centroids were calculated based on the coordinates of their vertices. The overall geometric center of the country was then derived as a weighted average of these centroids, using area of the small sub-areas as the weighting factor.

Several computational variants were analyzed, involving different coordinate reference systems (PL-LAEA, PL-1992, and local systems), as well as various projection methods from ellipsoidal to planar surfaces. The study identified the most accurate approach, capable of determining the geometric center of Poland with a precision of a few centimeters. Special attention was given to the impact of boundary definitions – whether including or excluding territorial waters – demonstrating that the location of the center can shift by several kilometers depending on the adopted boundary variant.

Final coordinates of Poland’s geometric center were determined for both variants: without territorial waters (variant A) and including them (variant B), and compared with previous attempts to define the country’s center. The paper highlights the importance of consistent boundary definitions and appropriate reference models in geodetic calculations and shows the potential to apply the proposed methodology to smaller administrative units such as voivodeships, counties, and municipalities. The findings are relevant for geodetic authorities, spatial planners, and for promotional or symbolic purposes related to the designation of national or regional “geographical centers”.