Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
A Global Navigation Satellite System (GNSS) receiver is, to some extent, a â??black boxâ?\nwhen its data is used for ionospheric studies. Our results based on Javad, Septentrio, Trimble, and\nLeica GNSS receivers have proven that the accuracy of the slant Total Electron Content (TEC)\ncalculation can differ significantly depending on the GNSS receiver type/model, because TEC\nmeasurements depend on the carrier phase tracking technique applied in a receiver. The\ncorrelation coefficient between carrier phase noise in L1 and L2 channels is considered as a possible\nindicator that shows if the L1-aided tracking technique or independent tracking is applied inside a\nreceiver. An empirical model of the TEC noise component was provided to determine the TEC\nnoise value in different types/models of GNSS receivers....
This paper presents a precise and fast method of ambiguity resolution (PREFMAR) for\nfrequencies L1/E1 and L5/E5a of GPS/GALILEO data. The developed method is designed for precise\nand fast determination of ambiguities in GNSS phase observations. Ambiguities are chosen based\non mathematical search functions. The fact that no varianceâ??covariance matrix (VC matrix) with a\nso-called float solution is needed proves the innovativeness of the developed method. Moreover,\nthe developed method enables determination of the ambiguities for short baseline double-difference\n(DD) observations....
Satellite imagery is used for many activities in different areas of the planet,\nincluding searching for alternative and sustainable sources to meet growing\nenergy demand to reduce greenhouse gas (GHG) emissions. One way to minimize\nthese effects and expand energy parks is to encourage local generation\nthrough the use of renewable sources, such as solar energy, which is free and\naffordable in many regions of the planet, but that in Brazil is not yet a reality.\nIn order to make an assertive decision when installing a solar power system,\none needs to use tools that involve remote sensing and geographic information\nsystems (GIS), and compile information and variables that are relevant\nto the subject of solar power generation and take into account the inherent\ngeographic space....
This paper theoretically derives the equivalence conditions for the loosely and tightly coupled GNSS/INS integration algorithms.\nFirstly, the equivalence is proved when using single epoch GNSS measurements, which means the GNSS processor provides\nstandalone solution. Then, the equivalence proof is further extended for the filtering solutions, which are usually applied for\ndifferential GNSS and precise point positioning. Based on these, different state and measurement models for GNSS/INS integration\nnavigation are summarized, and natural differences among these models are discussed. This indicates that once the same\nmeasurement and predict information are used, the integration would be equivalent no matter what kind of coupling schemes are\nused. A flight dataset with GNSS and tactical IMU data is used to evaluate the equivalence and discrepancies among four different\nmeasurement models, and the results confirm the theoretical derivations....
Because the accuracy of the existing airborne navigation is lacking in the polar region, it is difficult to ensure the safety and\nreliability of the aircraft when it is flying over the polar region. The integrated navigation system based on the inertial navigation\ntechnology uses multi-information fusion to assist collaborative navigation and obtain an indirect grid navigation algorithm that\ncombines the azimuth navigation algorithm and the grid navigation algorithm to solve the existing problems. This paper analyzes\nthe principle of the inertial navigation system in the polar region, the semiphysical simulation experiments are carried out by using\nthe navigation theory and the background engineering, and the accuracies of the integrated navigation system of the indirect grid\nframe in the polar region and the integrated navigation system in the middle and low latitudes are consistent, which verifies the\nfeasibility and effectiveness of the SINS/CNS/GPS integrated navigation system in the polar region. In addition, the paper provides\nthe theoretical basis and the application of engineering to achieve the SINS/CNS/GPS integrated navigation system in the\npolar region....
Loading....