Performance of Galileo satellite products determined from multi-frequency measurements

Abstract

Each Galileo satellite provides coherent navigation signals in four distinct frequency bands. International GNSS Service (IGS) analysis centers (ACs) typically determine Galileo satellite products based on the E1/E5a dual-frequency measurements due to the software limitation and the limited tracking capability of other signals in the early time. The goal of this contribution is to evaluate the quality of Galileo satellite products determined by using different dual-frequency (E1/E5a, E1/E5b, E1/E5, E1/E6) and multi-frequency (E1/E5a/E5b/E5/E6) measurements based on different sizes of ground networks. The performance of signal noise, the consistency of frequency-specific satellite phase center offsets and the stability of satellite phase biases are assessed in advance to confirm preconditions for multi-frequency processing. Orbit results from different dual-frequency measurements show that orbit precision determined from E1/E6 is clearly worse (about 35%) than that from other dual-frequency solutions. In view of a similar E1, E5a, E5b and E6 measurement quality, the degraded E1/E6 orbit performance is mainly attributed to the unfavorable noise amplification in the respective ionosphere-free linear combination. The advantage of using multi-frequency measurements over dual-frequency for precise orbit determination is clearly visible when using small networks. For instance, the ambiguity fixing rate is 80% for the multi-frequency solution while it is less than 40% for the dual-frequency solution if 150 s data sampling is employed in a 15-station network. Higher fixing rates result in better (more than 30%) satellite orbits and more robust satellite clock and phase bias products. In general, satellite phase bias products determined from a 20-station (or more) network are precise enough to conduct precise point positioning with ambiguity resolution (PPP-AR) applications. Multi-frequency kinematic PPP-AR solutions always show 5–10% precision improvement compared to those computed from dual-frequency observations.

Considerations for Eco-LeanSat Satellite Manufacturing and Recycling

“…In Europe, the construction and launch of the Galileo constellation began. The mass of these satellites is approximately 700 kg [132].…”

Overview of Space-Capable Global Navigation Satellite Systems Receivers: Heritage, Status and the Trend towards Miniaturization

“…In terms of technology, spaceborne receivers were developed that supported the increasing number of frequencies and signals of a single GNSS [7]. In addition, efforts to integrate other GNSS constellations, i.e., GLONASS, Galileo, BeiDou, QZSS and NavIC, have been realized for many modern receivers [8].…”

GPS, GLONASS, Galileo ve BeiDou GNSS Sistemlerinin 1. ve 2. Temel Frekanslarının Doluluk Analizi

“…Bu çalışma kapsamında multi-GNSS istasyonlarında yaygın olarak kullanılan sinyal frekansları dikkate alınmıştır: GPS (C1C C2W L1C L2W), GLONASS (C1C L1C C2P L2P), Galileo (C1C L1C C5Q L5Q) ve Beidou (C2I L2I C6I L6I). Bu sinyal kanallarının seçilmesindeki en önemli durum, analiz merkezlerinin birçoğunun uydu yörünge ve saat ürünlerini üretmek için kullandığı sinyal kanalları olması [25][26][27] ve çoğu IGS-MGEX alıcılarında bu sinyallerin mevcut olmasıdır. Bunun haricinde PPP tekniği ile faz başlangıç belirsizliği çözünürlüğü için, analiz merkezlerinin üretmiş olduğu BIAS SINEX [28] dosyalarının genellikle bu sinyal kanalları için üretiliyor olması (GLONASS hariç) da bu sinyal kanallarının tercih edilmesinde önemli bir rol oynamıştır.…”