Effect of different network geometry on GNSS results
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Tarih
2017-12-07
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Selçuk Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
GNSS (Global Navigation Satellite System) arazi ölçmelerinde jeodezik ağların kurulmasında sıkça kullanılır. Bir jeodezik ağı kurmak için, ağın türünü, tasarımını, doğruluk isteklerini bilmek gerekir. GNSS ağının ihtiyaç olduğu alanlar; haritalama, yer kabuğu hareketlerinin izlenmesi, geniş çaplı mühendislik projelerinin planlanması, kadastral çalışmalarının uygulanması ve CBS aktivitelerini içerir. GNSS ağında, noktalar nerede ihtiyaç duyulursa orada tesis edilir. Fakat noktalar arasındaki gözlem şeması önemlidir. Bu çalışmanın ana amacı; fazla gözlem sayısı ve alıcı sayısı düşünülerek GNSS ağında en uygun ölçü tasarımını belirlemektir. Bu kapsamda proje sahasında 6 nokta tesis edilmiştir. Oturumlar hazırlandıktan sonra, alıcı sayısı, noktalar arası uzaklık ve zaman göz önünde bulundurularak statik ölçüler gerçekleştirilmiştir. 3 günlük veri toplam sürecinde GNSS ağının farklı 4 çeşit ağ tasarımı denenmiştir. Veri toplama sürecinde iki ve üç alıcı kullanılmıştır. Birincisi bir sabit noktadan yeni noktalara ölçü yapan Hub metodudur (yeni nokta sayısı 6 dır). İkincisi ağın merkezindeki bir noktayı sabit alıp diğer noktaları gözlemleyen Star yöntemidir. Üçüncüsü bilinen bir noktadan tüm noktaların gözlemlendiği iki alıcılı Loop yöntemidir. Sonuncusu iki sabit noktalı ve üç alıcılı Loop yöntemidir. Seçilen projelerin türüne göre yöntemlerin üstünlükleri ve zayıflıkları bulunmaktadır. Sayısal sonuçlara göre fazla ölçü sayısındaki eksiklik ve kapalı lupların olmaması nedeniyle birinci ve ikinci yöntem, yüksek duyarlıklı GNSS ağ tasarımında tavsiye edilmez.
Global Navigation Satellite System (GNSS) is mostly used to establish geodetic networks in surveying engineering. To establish a geodetic network, one should have an understanding of the various types of geodetic networks, their design, accuracy requirements, and essence. The main area where GNSS networks are needed include mapping, tracking crustal movements, planning large engineering projects, implementing cadastral works, designing urbanization activities, GIS, etc. In GNSS network, stations are generally located where they are needed, but the observation schema between stations are important. The main goal of this research was to select the best observation schema of GNSS networks according to the number of receivers and the redundancy of the observation. In this research, six points were established after reconnaissance the field of the project. After preparation the sessions according to the number of receivers, time, and distance between points observations were made by using static method. Data collections were made by using two and three receivers. From data collected in three days four types of geometric design of GNSS network were selected. The first was Hub method that is from one fixed point the new points (i.e. six points in this study) were observed. The second one was Star method that is one fixed point in the center of the new network and observed unknown points. The third was Loop method 1 (using two receivers) where all baselines (i.e. 21 baselines in this study) were observed from one known point and the last was Loop method 2 (using three receivers) from one fixed point. These methods had some advantage and disadvantage according to the type of the project that are selected. Due to no redundancy, no close loop, and no nontrivial line between adjacent points the first and second methods are not recommended for the establishment of the precise GNSS network in our study.
Global Navigation Satellite System (GNSS) is mostly used to establish geodetic networks in surveying engineering. To establish a geodetic network, one should have an understanding of the various types of geodetic networks, their design, accuracy requirements, and essence. The main area where GNSS networks are needed include mapping, tracking crustal movements, planning large engineering projects, implementing cadastral works, designing urbanization activities, GIS, etc. In GNSS network, stations are generally located where they are needed, but the observation schema between stations are important. The main goal of this research was to select the best observation schema of GNSS networks according to the number of receivers and the redundancy of the observation. In this research, six points were established after reconnaissance the field of the project. After preparation the sessions according to the number of receivers, time, and distance between points observations were made by using static method. Data collections were made by using two and three receivers. From data collected in three days four types of geometric design of GNSS network were selected. The first was Hub method that is from one fixed point the new points (i.e. six points in this study) were observed. The second one was Star method that is one fixed point in the center of the new network and observed unknown points. The third was Loop method 1 (using two receivers) where all baselines (i.e. 21 baselines in this study) were observed from one known point and the last was Loop method 2 (using three receivers) from one fixed point. These methods had some advantage and disadvantage according to the type of the project that are selected. Due to no redundancy, no close loop, and no nontrivial line between adjacent points the first and second methods are not recommended for the establishment of the precise GNSS network in our study.
Açıklama
Anahtar Kelimeler
GNSS ağ tasarımı, Fazla ölçü, Statik yöntem, Oturum, GNSS network, Redundancy, Static method, Session
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Ahmed, S. F. A. (2017). Effect of different network geometry on GNSS results. Selçuk Üniversitesi, Yayımlanmış yüksek lisans tezi, Konya.
