Investigation of the positional accuracy of orthophoto and DEM Products generated from UAV data with the PPK method: A case study of Horseshoe Island, Antarctica

Abstract

Monitoring changes in glacial areas is important for a better understanding of global climate change processes and adaptation of humanity to future processes. Unmanned aerial vehicle (UAV) photogrammetry, one of the methods used to monitor glacier changes, uses positioning methods based on global navigation satellite systems (GNSS) to monitor cryosphere and glacier changes with high positional accuracy. In this study, the positional accuracy of photogrammetric products generated using the Post Processing Kinematic (PPK) method was investigated in a test area designated for glacier monitoring on Horseshoe Island, which hosts the Turkish Scientific Research Camp in Antarctica. The positional accuracy of the orthophoto and digital elevation model (DEM) generated based on the Structure from Motion (SfM) method using aerial photographs was determined with ground control points whose positions were determined using the classical real-time kinematic positioning (RTK) method in the field. The root mean square error values calculated for horizontal and vertical coordinates are 1.05 cm, 0.52 cm, and 11.33 cm, respectively.

Keywords

• Antarctica
• UAV
• PPK
• Orthophoto
• DEM

PPK yöntemi ile İHA verilerinden üretilen ortofoto ve SYM ürünlerinin konumsal doğruluğunun araştırılması: Antarktika’daki Horseshoe Adası örneği

Öz

Küresel iklim değişikliği süreçlerinin daha iyi anlaşılabilmesi ve insanlığın gelecekteki süreçlere uyum sağlayabilmesi açısından buzul alanlardaki değişikliklerin izlenmesi önem taşımaktadır. Buzul değişimlerinin takibi için kullanılan yöntemlerden birisi olan insansız hava aracı (İHA) fotogrametrisi ile kriyosferin ve buzul değişikliklerinin yüksek konumsal doğrulukla izlenebilmesi için küresel konum belirleme sistemlerine (Global Navigation Satellite System-GNSS) dayanan konum belirleme yöntemleri kullanılmaktadır. Bu çalışmada Antarktika'da, Türk Bilimsel Araştırma Kampı'na ev sahipliği yapan Horseshoe Adası'nda, buzul takibi amacıyla belirlenen bir test alanında kinematik ölçme sonrası değerlendirme (Post Processing Kinematic-PPK) yöntemi kullanılarak üretilen fotogrametrik ürünlerin konumsal doğruluğu araştırılmıştır. Hava fotoğraflarından hareket ile nesne oluşturma (Structure from Motion-SfM) yöntemine dayanarak üretilen ortofoto ve sayısal yükseklik modelinin (SYM) konum doğruluğu, arazide klasik gerçek zamanlı kinematik (Real Time Kinematic-RTK) konum belirleme yöntemiyle konumları belirlenmiş yer kontrol noktaları kullanılarak elde edilmiştir. Yatay ve düşey koordinatlar için hesaplanan karesel ortalama hata değerleri sırasıyla 1.05 cm, 0.52 cm ve 11.33 cm’dir.

Anahtar Kelimeler

• Antarktika
• İHA
• PPK
• Ortofoto
• SYM

Kaynakça

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