Evaluation of GNSS Observation Timing using Dilution of Precision and Satellite Visibility Analysis in North-East, Nigeria

Abstract

This study evaluates GNSS observation timing in Northeast Nigeria using Dilution of Precision (DOP) and satellite visibility analyses to determine optimal periods for data collection and evaluate temporal variations in positioning conditions. Twelve weeks of GNSS data were analysed using descriptive statistics, paired-samples t-tests, ANOVA, and orthogonal contrast analysis. The results showed that nighttime observations provided significantly better satellite geometry, with lower mean DOP values (2.447) than daytime observations (2.624), and higher satellite visibility (8.429 satellites compared to 8.292 satellites during the day). Statistical tests confirmed these differences to be significant. However, ANOVA results revealed no significant differences were found among morning, afternoon, and evening observation periods (), indicating relatively stable GNSS performance throughout the daytime. These findings suggest that although nighttime observations offer slightly more favourable positioning conditions, reliable and acceptable GNSS accuracy can be achieved at any time of the day. This flexibility is particularly beneficial in Northeast Nigeria, where security concerns often restrict fieldwork schedules. The study concludes that GNSS surveys can be effectively conducted across different observation periods without substantial loss of positioning quality, thereby improving operational efficiency, safety, and survey planning for geospatial, infrastructure, and security-related applications.