Net Orbit 6.0 Crack Serial Keygen Review ##HOT##
Regena Morguson
Anisotropic expansion of a BEC along the direction of spin-orbit coupling (x axis) with the Raman coupling strength Ω=2.5ER, and various detunings of (a) δ=2.71ER, (b) δ=1.36ER, and (c) δ=0.54ER, from left to right, respectively. The first row shows the experimental integrated cross section of the condensate (dotted red curves) overlaid with results from the GPE simulation (solid black curves). The second row plots the location of the 20% and 80% quantiles with respect to the initial cloud center. The shaded regions present the GPE simulations, while the data points (and dotted lines to guide the eye) are the experimental measurements smoothed slightly by averaging the nearest 3 times. Error estimates are the standard deviation of 5 samples and are comparable with about twice the camera pixel resolution. The insets show the dispersion relation, with the region of negative effective mass lightly shaded. The bottom two rows show the evolution of the expanding condensate from the experiment (upper) and corresponding single-band axially symmetric 3D GPE simulations (lower). The dashed white lines depict the quantiles from the plot above. All experimental data presented here are from in situ imaging.
Introduction: Provision of critical care and resuscitation was not practical during early missions into space. Given likely advancements in commercial spaceflight and increased human presence in low Earth orbit (LEO) in the coming decades, development of these capabilities should be considered as the likelihood of emergent medical evacuation increases.
Purpose: Due to improved survival durations and enhanced surveillance modalities, metastases of systemic malignancies to the orbit are increasing. This review is intended to discuss the epidemiologic, clinical, and management features of orbital metastases. Methods: A literature search for relevant publications on the topic was performed via PubMed, and the appropriate data were extracted from these manuscripts. Results: While rare, metastases to the orbit are regularly encountered in clinical practice. The overwhelming majority of these lesions present in adult patients, and metastatic disease may emerge several years after the diagnosis of the initial cancer. Subjectively, these lesions tend to present with complaints of diplopia, blurred vision, and pain, and objective signs tended to include vision loss, limitation of extraocular motility, proptosis, the presence of a palpable mass, and ptosis. Different studies reported a variety of primary tumors, although breast and lung malignancies were generally among the most common. A sizeable portion of patients may not have a known primary malignancy. After detection, survival rates are generally short, and metastatic disease suggests a worrisome prognosis. Radiation therapy may alleviate symptoms. Conclusions: Metastases of systemic disease present with specific subjective, clinical, and radiographic features. Furthermore, these lesions may present years after an initial diagnosis. Clinicians should be aware of the implications of this malady on patient survival and must consider interventions to improve quality of life.
Last year, a Long March 2D rocket took off from the Jiuquan Satellite Launch Centre in the Gobi Desert carrying a satellite called Micius, named after an ancient Chinese philosopher who died in 391 B.C. The rocket placed Micius in a Sun-synchronous orbit so that it passes over the same point on Earth at the same time each day.
But Micius changes all that because it orbits at an altitude of 500 kilometers, and for most of this distance, any photons making the journey travel through a vacuum. To minimize the amount of atmosphere in the way, the Chinese team set up its ground station in Ngari in Tibet at an altitude of over 4,000 meters. So the distance from the ground to the satellite varies from 1,400 kilometers when it is near the horizon to 500 kilometers when it is overhead.
The measurement environment, the technique used for POD processing and the mission application of the satellite can affect the performance of the POD process. Furthermore, besides accuracy, a growing interest has been in reducing latency in achieving a precise solution, which benefits many end-users as it provides faster access to the required orbit solutions (Gebre-Egziabher and Gleason 2009).
The development of many new space applications in the area of navigation, telecommunication, remote sensing and earth observation systems can benefit from the precise tracking of satellite orbits using onboard GNSS receiver data. Future trends show that LEO satellites have the potential to deliver several benefits over medium earth orbit (MEO) satellites in terms of navigation, precise point positioning and timing (PNT), as well as location-enabled communications (Prol et al. 2022). This is because LEO satellites are at significantly lower altitudes than MEO and geosynchronous (GEO) GNSS satellites and operate at higher speed (Borthomieu 2014; Peterson 2003).
Existing literature review (Allahvirdi-Zadeh et al. 2021b) mainly covers the state-of-the-art POD based on undifferenced GNSS observations. A work-in-progress review paper (Selvan et al. 2021) made a general review on the different POD techniques of LEO satellites. To the best of the author's knowledge, there is no existing systematic literature review on POD of LEO satellites. Therefore, we performed a systematic review based on primary studies making use of the procedure suggested by PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) (Kitchenham 2004). The review did not focus on the theoretical background behind POD as stated in several books (for example, Montenbruck et al. 2002). Instead, a clear view on various POD and its associated results is provided by summarizing factors driving the POD solution. The review is based on the context of four research questions, which were carefully selected to fulfill the aim of the systematic review in identifying the data sources used, POD technique implemented, validation method applied, and accuracy level obtained. Table 1 provides a list of research questions used in the review process. The summarized results not only provide a clear picture on which orbit model, observation types, estimators, processing procedure and validation method have performed better, but it also shows categories which require further improvements. Therefore, the review helps researchers focus on areas that need further improvements and presents the POD strategies for the highest accuracy.
Non-GNSS refers to data other than that from the GNSS receiver utilized in the POD. This includes data from SLR, DORIS as well as accelerometer and attitude data. Non-GNSS data were used in 16 (11.7%) primary studies. Certain primary studies made use of a combination of two or more non-GNSS-based observations to estimate the precise orbits of the satellite. In addition, apart from the listed categories of data sources, there are other approaches implemented by the primary studies in POD. This includes studies utilizing the radio interferometer observations (Sakamoto and Nishio 2011) and inter-satellite links (Li et al. 2019a). These studies did not use any onboard GNSS data from the receiver or any data from the traditional non-GNSS-based technique. They used completely different approaches including interferometry-based satellite orbit estimation and inter-satellite link-based estimation of satellite orbits. For the sake of simplicity, these studies were also categorized as non-GNSS in Fig. 1.
Several types of POD techniques were applied in the primary studies. For practical convenience, different techniques are organized based on four characteristics: (1) orbit model, (2) observations, (3) estimator and (4) processing procedure. Table 2 shows the main topics of each category. Figure 3 shows the number of studies using each of these categories. A clear trend is observed for techniques using reduced-dynamic orbits, least-squares solvers, dual-frequency (DF) signals with undifferenced (UD) phase and code observations, in post-processing mode. Detailed information about the POD techniques in each of the primary studies is shown in the next subsections, with the corresponding meaning of the abbreviations.
The orbit models define the rules to govern the satellite motion within the estimated trajectory. The three main methods used by the primary studies are kinematic, dynamic and reduced dynamic. The kinematic orbit model can be related to a point positioning method that determines the orbit trajectory with a purely geometrical relation. The LEO 3D coordinates are obtained epoch-by-epoch as independent solutions. The main output is epoch-wise ephemeris with discrete time solutions. The kinematic model provides 3D coordinates, ambiguities and receiver clocks when using GNSS data. Contrary to kinematic orbit, the dynamic model depends solely on an equation of motion governed by physical laws. Force models are used to represent the gravitational and non-gravitational dynamic parameters. Main parameters are related to the gravitational forces, atmospheric drag, solar radiation pressure and earth radiation pressure. As a result, the purely dynamic POD provides continuous positions, even if the initial positions have data gaps. Since it is difficult to determine an ideal dynamic orbit for the heavily perturbed environment of LEO satellites, uncertainties and perturbations vary significantly depending on the adopted force models. The orbit errors, therefore, grow with the satellite arc length. The force models have been significantly improved in the last few years since the GRACE and GOCE gravity missions were successfully used to determine static/temporal gravity field models (Förste et al. 2011). Nevertheless, the reduced-dynamic model is typically used to attenuate the unmodeled or mismodeled force mode errors. The reduced-dynamic technique combines the kinematic and dynamic models by introducing a stochastic process in the representation of the trajectory. The residual of the estimations is adjusted within the orbit determination to help the compensation of remaining force model deficiencies. Most often, empirical accelerations are included in the system at the radial, along-track, and cross-track (RAC) directions. As a disadvantage, the reduced-dynamic solutions need denser and geometrically stronger tracking data. Therefore, the reduced dynamic orbits are less sensitive to dynamic modeling errors but more to measurement errors (Guo et al. 2014). Table 3 provides the advantages and disadvantages of the three orbit models.
dd2b598166