Investigation of the effect of GCP number and distribution on photogrammetric product accuracy in UAV photogrammetry

Abstract

Recently, photogrammetric products produced using Unmanned Aerial Vehicles (UAVs) are frequently preferred for disaster management, geological, and meteorological studies, urban studies and military purposes. Obtaining products with UAV photogrammetry provides a significant advantage over ground-based methods in terms of speed and cost. At the same time, the accuracy of the products produced is of particular importance. In this study, the effects of the number of Ground Control Points (GCPs) and GCP network design on accuracy were investigated. In this direction, 12 GCPs with homogeneous distribution in the study area were established and their locations were determined by GNSS measurements. Then, scenarios with different number of GCPs and different network designs were created, and the accuracy of these points were evaluated. As a result, it has been concluded that 5 GCPs homogeneously distributed in the field is sufficient for the products at high accuracy (≤ 10 cm) required in geomatics applications, increasing the number of the GCPs will not benefit the accuracy of the project and this process is disadvantageous in terms of increasing the cost along with the speed.

Keywords

• UAV Photogrammetry
• GCP
• Network design

Project Number

TÜBİTAK 122Y125 ve CÜBAP M855

İHA fotogrametrisinde YKN sayısı ve dağılımının fotogrametrik ürün doğruluğuna etkisinin araştırılması

Abstract

Son zamanlarda İnsansız Hava Araçları (İHA) kullanılarak üretilen fotogrametrik ürünler afet yönetimi, jeolojik ve meteorolojik araştırmalar, şehircilik çalışmaları ve askeri amaçlar için sıklıkla tercih edilmektedir. İHA fotogrametrisi ile ürün elde etmek hız ve maliyet açısından yersel yöntemlere göre önemli bir avantaj sağlamaktadır. Aynı zamanda üretilen ürünlerin doğruluğu da ayrı bir önem arz etmektedir. Bu çalışmada, Yer Kontrol Noktası (YKN) sayısının ve YKN ağ tasarımının doğruluk üzerindeki etkileri araştırılmıştır. Bu doğrultuda çalışma alanında homojen dağılım gösteren 12 nokta tesis edilerek GNSS ölçümleri ile konumları belirlenmiştir. Ardından, farklı YKN sayısına ve farklı ağ tasarımına sahip senaryolar oluşturularak bu noktaların doğrulukları değerlendirilmiştir. Sonuç olarak, arazide homojen dağılım gösteren 5 YKN’nin geomatik uygulamalarında gereksinim duyulan yüksek doğruluklu (≤ 10 cm) ürünler için yeterli olduğu, YKN sayısını artırmanın projenin doğruluğuna fayda sağlamayacağı ve bu işlemin hız ile birlikte maliyeti artırması bakımından dezavantajlı olduğu sonucuna varılmıştır.

Keywords

• İHA fotogrametrisi
• YKN
• Ağ tasarımı

Project Number

TÜBİTAK 122Y125 ve CÜBAP M855

Ethical Statement

Bu çalışmada etik kurallara uyulmuştur.

Thanks

Yazarlar çalışmayı destekleyen TÜBİTAK'a ve Sİvas Cumhuriyet Üniversitesine teşekkür ederler.

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