Reha Metin ALKAN, Veli İLÇİ, İ Murat OZULU

Klasik GNSS Veri Değerlendirme Yazılımlarına Alternatif Olarak Web- tabanlı Online Değerlendirme Servisleri

Bu çalışmada web-tabanlı online değerlendirme servislerinin ölçme uygulamalarında kullanılabilirlikleri ve doğruluk performansları analiz edilmiştir. Çalışmada 2 farklı yaklaşımla değerlendirme yapan servislerele alınmıştır. Bunlardan birinci gruptakiler, CSRS-PPP, APPS, GAPS ve magicGNSS, PPP tekniği ile noktaların mutlak anlamda konumlarını belirlemekte iken; ikinci gruptakiler, OPUS ve AUSPOS, ölçme yapılan noktanın etrafındaki International GNSS Service (IGS), CORS (Continuously Operating Reference Station) vb. ağlara ait noktaları sabit (referans) istasyon olarak alıp, rölatif yöntemle konum belirlemektedir. Bu amaçla TUSAGA-Aktif ağına ait 146 noktadan biri olan CORU noktasında statik olarak toplanan 24 saatlik veri seti, bu web-tabanlı online GNSS veri değerlendirme servislerine gönderilmiş ve değerlendirilmiştir. Ek olarak doğruluğun ölçme süresi ile ilişkisini de belirlemek için, 24 saatlik veri seti, 1, 2, 4, 6 ve 12'şer saatlik alt gruplara ayrılmış ve bunların her biri anılan bu servislerle değerlendirilmiştir. Elde edilen sonuçlar PPP tekniği ile özellikle uzun ölçme sürelerine sahip veri setleri (2 saat ve daha fazla) kullanılarak cm-dm mertebesindeki doğruluklarla konum belirlenebileceğini göstermiştir. Rölatif yöntem kullanarak çözüm yapan web-tabanlı online servislerle ise klasik jeodezik yaklaşımlarla, daha güvenilir ve yüksek doğruluklarla nokta konumları belirlenmiştir. Sonuçlar, cm'ler mertebesinde yatay konum, dm ve altı mertebesinde yükseklik doğruluğuna 2 saatlik ölçme süresinin yeterli olduğunu göstermiştir. Genel olarak söylenecek olursa, çalışmadan elde edilen sonuçlar onlineGNSS değerlendirme servisleri ile ekonomik ve kolay bir şekilde, pek çok ölçme uygulamasına yeterli olacak doğruluklarla konum belirlemenin mümkün olduğunu göstermiştir.

Web-based Online Data Processing Services as an Alternative to Conventional GNSS Processing Software

In this study, the usability and accuracy assessment of web-based online processing services on the surveying applications were analyzed. Services processing with two different approaches were handled for the study. While the first group these, i.e. CSRS-PPP, APPS, GAPS and magicGNSS, are able to determine the coordinates of the points by using PPP technique, the second group, i.e. OPUS and AUSPOS, determines the coordinates with a relative method by using nearby International GNSS Service (IGS) and Local Continuously Operating Reference Station (CORS) network points as reference stations. For this purpose, data set of 24h which was statically collected from CORU point as one of the 146 points of TUSAGA-Aktif network was sent to this web-based online GNSS Data Processing Services. Additionally, in order to assess the attainable accuracy obtained from the handled online service as a function of occupation time, data set of 24-hour-data file was divided into several shorter sessions as; 1, 2, 4, 6 and 12 hour sub-sessions. All these observation files were processed with this web-based online services. The obtained results indicated that it is possible to determine the positions with cm to dm level accuracy by using PPP technique especially when using the data set having longer occupation time

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İnternet kaynakları 1-http://webapp.geod.nrcan.gc.ca/geod/toolsoutils/ppp.php?locale=en (30.01.2017)
2- http://apps.gdgps.net (30.01.2017)
3- http://gaps.gge.unb.ca (30.01.2017)
4- http://magicgnss.gmv.com (30.01.2017)
5- http://sopac.ucsd.edu/scout.shtml (30.01.2017)
6- http://www.ngs.noaa.gov/OPUS (30.01.2017)
7- http://www.ga.gov.au/bin/gps.pl (30.01.2017)