Low Earth Orbit Constellations Research Articles

Operating Characteristics of a Wave-Driven Plasma Thruster for Cutting-Edge Low Earth Orbit Constellations

This paper outlines the development phases of a wave-driven Helicon Plasma Thruster for cutting-edge Low Earth Orbit (LEO) constellations. The two-stage ambipolar electric propulsion (EP) system combines the efficient ionization of an ultra-compact helicon reactor with plasma acceleration based on an ambipolar electric field provided by a magnetic nozzle. This paper reveals maturation challenges associated with an emerging EP system in the hundreds-watt class, followed by outlook strategies. A 3 cm diameter helicon reactor was operated using argon gas under a time-modulated RF power envelope ranging from 250 W to 500 W with a fixed magnetic field strength of 400 G. Magnetically enhanced inductively coupled plasma reactor characteristics based on half-wavelength right helical and Nagoya Type III antennas under capacitive (E-mode), inductive (W-mode), and wave coupling (W-mode) were systematically investigated based on Optical Emission Spectroscopy. The operation characteristics of a wave-heated reactor based on helicon configuration were investigated as a function of different operating parameters. This work demonstrates the ability of two-stage HPT using a compact helicon reactor and a cusped magnetic field to outperform today’s LEO spacecraft propulsion.

Collaborative last-hop scheduling strategy for large-scale LEO constellation routing

The transmission of data packets from satellites to Earth Stations (ESs) is the last hop of satellite network routing. As the final stage of packet transmission, the use of different scheduling strategies directly affects the throughput of the satellite network. Traditionally, researchers have attempted to enhance network performance by investigating inter-satellite routing protocols or inter-satellite data offloading strategies. However, these approaches have failed to address scheduling issues in the last hop of large-scale Low Earth Orbit (LEO) constellations. In this paper, we present the first Cooperative Last-Hop Scheduling (CLHS) strategy for routing in large-scale LEO constellations based on a bidirectional communication domain. In this strategy, we first utilize the bidirectional communication domain to determine the communication ranges of satellites and ESs. Subsequently, an information flow is established to interact with ESs and satellites. The ESs receive and reconstruct the Information Matrix (IM) from the information flow. Moreover, we propose the Maximum Decision Value Priority (MDVP) algorithm, which takes the reconstructed IM as input and computes the scheduling commands for satellites within the communication range of the ESs. To address the issue of multiple ESs simultaneously scheduling the same satellite, we introduce the Collision Avoidance Algorithm (CAA). Finally, to enhance the data packet transmission efficiency of the scheduled satellites, we propose the Weighted First-In-First-Out (WFIFO) algorithm, which is specifically designed for satellite packet dequeuing. We validate the CLHS through simulations on two satellite constellations: the first-generation Starlink constellation with 4409 satellites and the GW-2 constellation with 6912 satellites. The results show that CLHS can achieve better network throughput than traditional strategies. CLHS provides a novel method of scheduling the last hop in large-scale satellite constellations.

Analysis of inter-satellite optical wireless communication systems for enhanced data transmission in satellite constellations

This research focuses on the comprehensive performance analysis of inter-satellite optical wireless communication (IsOWC) systems, specifically tailored for high data rate applications in Earth observation satellites. The research employs OptiSystem 21.0 simulation software to model and analyze the IsOWC systems. The simulation scenario is set in a low Earth orbit (LEO) constellation, typical for Earth observation satellites. Various system parameters are systematically varied to assess their impact on performance. Modulation types, such as non-return-to-zero (NRZ) and return-to-zero (RZ) are analyzed for their influence on the quality (Q) factor. The study further explores the effects of different wavelengths, antenna apertures, transmitter output powers, and link distances on the IsOWC system performance. This research provides valuable insights into optimizing IsOWC systems for Earth observation satellites, contributing to the advancement of communication technologies in satellite networks. The research shows that the NRZ modulation consistently outperforms RZ modulation in terms of maximum Q factor and minimum BER across different antenna apertures and power levels. Additionally, shorter wavelengths exhibit improved performance, while larger antenna apertures contribute to enhanced signal quality. The relationship between transmitter power and data rate is also investigated, demonstrating the potential for achieving higher data rates with increased transmitter power. The findings guide the selection of parameters to achieve optimal performance, ensuring efficient data transfer and meeting the demands of contemporary Earth observation missions. This study provides conclusive evidence that the 1350 nm wavelength outperforms the 1550 nm wavelength in reliable and high-data-rate optical wireless communications, offering higher received power, superior signal quality, and lower bit error rates. This makes it a preferred choice for systems in challenging space environments and could enhance future satellite communication architectures.

Navigation Resource Allocation Algorithm for LEO Constellations Based on Dynamic Programming

Navigation resource allocation for low-earth-orbit (LEO) constellations refers to the optimal allocation of navigational assets when the number and allocation of satellites in the LEO constellation have been determined. LEO constellations can not only transmit navigation enhancement signals but also enable space-based monitoring (SBM) for real-time assessment of GNSS signal quality. However, proximity in the frequencies of LEO navigation signals and SBM can lead to significant interference, necessitating isolated transmission and reception. This separation requires that SBM and navigation signal transmission be carried out by different satellites within the constellation, thus demanding a strategic allocation of satellite resources. Given the vast number of satellites and their rapid movement, the visibility among LEO, medium-earth-orbit (MEO), and geostationary orbit (GEO) satellites is highly dynamic, presenting substantial challenges in resource allocation due to the computational intensity involved. Therefore, this paper proposes an optimal allocation algorithm for LEO constellation navigation resources based on dynamic programming. In this algorithm, a network model for the allocation of navigation resources in LEO constellations is initially established. Under the constraints of visibility time windows and onboard transmission and reception isolation, the objective is set to minimize the number of LEO satellites used while achieving effective navigation signal transmission and SBM. The constraints of resource allocation and the mathematical expression of the optimization objective are derived. A dynamic programming approach is then employed to determine the optimal resource allocation scheme. Analytical results demonstrate that compared to Greedy and Divide-and-Conquer algorithms, this algorithm achieves the highest resource utilization rate and the lowest computational complexity, making it highly valuable for future resource allocation in LEO constellations.

UPDs estimation and ambiguity resolution performance evaluation of LEO navigation system

Low-Earth orbit (LEO) satellites have fast motion and thus provide rapid geometric change relation to the ground stations in a short period of time, which are expected to improve the positioning performance. In this study, a LEO constellation of 160 LEO satellites was simulated and simulated LEO observation data at global, European, and American stations were used to estimate the uncalibrated phase delays (UPDs) and achieve static and kinematic precise point positioning (PPP) ambiguity resolution (AR). The quality of the estimated UPD products were evaluated. More than 89 % and 96 % of the wide- and narrow-lane UPDs had a posteriori residual of less than 0.15 and 0.25 cycles, respectively. In static PPP, all ambiguity fixing rates were larger than 63 %. Compared with float solutions, the average convergence time of the fix solutions at the global, European and American stations was accelerated by 8 %, 6 % and 7 %, respectively; the average root-mean-square errors (RMSEs) in the east, north, and up components at the global, European and American stations were decreased by (22 %, 20 %, 15 %), (36 %, 34 %, 28 %) and (44 %, 31 %, 29 %), respectively. In kinematic PPP, all ambiguity fixing rates were larger than 40 %. Compared with float solutions, the average convergence time of the fix solutions at the global, European and American stations was accelerated by 4 %, 19 % and 14 %, respectively; the average RMSEs in the east, north, and up components at the global, European and American stations were decreased by (10 %, 10 %, 7 %), (27 %, 22 %, 11 %) and (32 %, 20 %, 10 %), respectively. In both static and kinematic PPP, AR accelerated the convergence time and improved the positioning accuracy.

A study on THz communications between Low Earth Orbit constellations and Earth Stations

A non-terrestrial system that uses Terahertz (THz) frequencies is a potential solution to achieving equal access to the Internet worldwide. This paper describes a non-terrestrial system that consists of a Low Earth Orbit (LEO) constellation, Earth Stations in Motion (ESIMs) and standard Earth stations. We examine the effects of rain, fog, clouds and atmospheric gases for this non-terrestrial system for frequencies between 100-300 GHz. The research findings suggest that the frequency bands between 102 - 109.5 GHz are rather suitable for communication between Earth stations and satellites, including ESIMs, reaching in a critical scenario uplink data rates of up to 2.6 Gbits/s with 0.5 GHz of bandwidth or up to 12 Gbits/s with 5 GHz of bandwidth in uplink. For the downlink, we can reach up to 6 Mbits/s with a transmitted power of 29 dBW, but if we increase the power transmitted by satellites, it is possible to reach up to 25 Gbits/s with 2.5GHz of bandwidth. Under clear, blue-sky conditions, we can achieve a maximum data rate of 17.3 Gbits/s for downlink and uplink. For inter-satellite links (communications between satellites in the same orbit or between different orbits), the frequency bands between 111.8 - 114.25 GHz, 116 - 123 GHz, 174.5 - 182 GHz, 185 - 190 GHz are viable, offering speeds from 1.5 to 2.51 Gbits/s when using a uniform rectangular array with 625 radiating elements. This research provides new findings from the amalgamation of existing literature, which is crucial for the future allocation of optimal frequencies between 100 - 300 GHz for satellite services.

Elevating performance in BDS-3 Precise Point Positioning Ambiguity Resolution through LEO augmented constellations

With the help of constellations combined BDS-3 (BeiDou Navigation Satellite System) and LEO (Low Earth Orbit), we aim to improve the performances of PPP (Precise Point Positioning) and PPP Ambiguity Resolution (PPP-AR). First, LEO constellations with 66, 96, 156, 192, 270, and 288 satellites are designed to establish six LEO augmented constellations. Based on four challenge scenarios, PPP of six LEO augmented constellations are performed. Even in the strip-shaped obstruction area losing more than 60% of observations, the positioning accuracies of static PPP are improved by (1.0%, 5.7%, 0.2%) for BDS+66LEO, and (14.9%, 33.7%, 7.5%) for BDS+288LEO in the east, north, and up components. The positioning accuracy and convergence time improve quickly as the number of LEO satellites increased from 66 to 156, and slowdown from 192 to 288. Two constellations, BDS+156LEO and BDS+192LEO, are considered to strike the balance of acceptable PPP performance and constellation load. Then, the performance of PPP-AR is realized with the estimated UPD (Uncalibrated Phase Delay). The correlations among geodetic parameters and ambiguities deriving from the post-fit variance–covariance matrix are analyzed to illustrate the enhancement of LEO augmented constellations. Under the condition of 20°elevation angle occlusion with azimuth ranging from 0 to 360°, BDS+156LEO can achieve an ambiguity fix rate of up to 98.37% with a faster mean TTFF (Time To First Fix) of 12.76 min, and the positioning accuracies in the east, north, and up components are improved by 28.2%, 21.4%, and 15.1% respectively, compared with BDS-3. BDS+192LEO realized an 98.42% ambiguity fixing rate, and improved BDS-3 by 31.4%, 26.7% and 11.5% with its TTFF been 12.25 min.

BRDF-Based Photometric Modeling of LEO Constellation Satellite from Massive Observations

BRDF-Based Photometric Modeling of LEO Constellation Satellite from Massive Observations

A DRL-Based Satellite Service Allocation Method in LEO Satellite Networks

Satellite computing represents a recent computational paradigm in the development of low Earth orbit (LEO) satellites. It aims to augment the capabilities of LEO satellites beyond their current transparent relay functions by enabling real-time processing, thereby providing low-latency computational services to end users. In LEO constellations, a significant deployment of computationally capable satellites is orchestrated to offer enhanced computational resources. Challenges arise in the optimal allocation of terminal services to the most suitable satellite due to overlapping coverage among neighboring satellites, compounded by constraints on satellite energy and computational resources. The satellite service allocation (SSA) problem is recognized as NP-hard, yet assessing allocation methods through results allows for the application of deep reinforcement learning (DRL) to obtain improved solutions, partially addressing the SSA challenge. In this paper, we introduce a satellite computing capability model to quantify satellite computational resources. A DRL model is proposed to address service demands, computational resources, and resolve service allocation conflicts, strategically placing each service on appropriate servers. Through simulation experiments, numerical results demonstrate the superiority of our proposed method over baseline approaches in service allocation and satellite resource utilization, showcasing advancements in this field.

LEO satellite constellations configuration based on the Doppler effect in laser intersatellite links

SummaryThis paper presents low Earth orbit (LEO) satellite constellation configuration based on the performance of Doppler effect in laser intersatellite links (LISLs). It studies the impact of the LEO constellation's parameters on the performance of the Doppler effect in LISLs. The paper aims to develop LEO satellite constellation configurations that evolve LISLs with minimal Doppler shift. It evaluates the impact of the variation of the relative distance, the inclination angle of the LEO constellation orbital planes, the orbital planes number in the LEO constellation, and the altitude on the performance of Doppler wavelength shift (DWS) in LISLs, for different operating laser wavelengths (OLWs) with respect to two possible intersatellite links (ISL) connection modes within the constellation, straight ISL (n‐to‐n) and inclined ISL (n‐to‐n − 1). n is the order of the satellite in the orbital plane. Simulations are conducted to evaluate the performance of these configurations in terms of altitude, OLW, inclination angle, and the number of orbital planes. In addition, both OneWeb and Starlink constellations are studied to evaluate DWS performance. The study demonstrates that DWS decreases either with the diminution of the relative distance between linked LEO satellites, the inclination of LEO constellation, and the OLW, or with the augmentation of the orbital planes number and altitude. Moreover, the overall DWS between two LEO satellites in the proposed constellation is at least 50% lower than the constellation configuration in other literature. The paper proposes the LEO constellation's configurations that perform LISLs with less possible Doppler effect by optimizing the LEO constellation parameters that impact the Doppler effect. The result of this study helps in the early stage of LEO satellite constellation designing in terms of payload simplicity and cost.

Demand and key technology for a LEO constellation as augmentation of satellite navigation systems

A Low Earth Orbit (LEO) constellation augmenting satellite navigation is important in the future development of Global Navigation Satellite System (GNSS). GNSS augmented by LEO constellations can improve not only the accuracy of Positioning, Navigation, and Timing (PNT), but also the consistency and reliability of secure PNT system. This paper mainly analyzes the diverse demands of different PNT users for LEO augmented GNSS, including the precision demand in real-time, the availability demand in special areas, the navigation signal enhancement demand in complex electromagnetic environments, and the integrity demand with high security. Correspondingly, the possible contributions of LEO constellations to PNT performance are analyzed from multiple aspects. A particular attention is paid to the special PNT user requirements that cannot be fulfilled with existing GNSS, such as the PNT service demand in the polar regions and the onboard GNSS orbit determination demand of some LEO satellites. The key technologies to be considered in the constellation design, function realization, and payload development of the LEO-augmented navigation system are summarized.

The pointing uncertainty Region's analysis of inter-satellite laser alignment systems under multiple uncertainties

Laser inter-satellite links (LISLs) are crucial for enabling rapid information exchange within low earth orbit (LEO) constellations. Previous research on laser link establishment often relied on the idealized probability density function (PDF) of the pointing uncertainty regions (PURs) when designing scan-and-capture methods, neglecting the impact of various practical uncertainties. To address the above issues, there is an urgent need to analyze the practical uncertainties to enhance the stability and reliability of LISL. This paper first provides a comprehensive introduction to the alignment process in LISL and mathematically formulates typical sources of uncertainty errors. Subsequently, a generalized system model (GSM) for laser link establishment was established at three stages: Orbit, Attitude, and Laser terminal. Finally, we integrate uncertainty models into the GSM and propose a PUR generating method to obtain precise PDFs. The research method proposed in this study can consider the influence of multiple uncertainties and generate the PDF for the PURs. Compared with traditional research, the PDF obtained by fitting the oscillation range considering dynamics is more detailed. By analyzing the PDF generated by typical uncertainty errors, it is observed that the orbit initial uncertainty may be the predominant factor influencing the PUR.

Geometrical design method of Walker constellation in non-terrestrial network

To meet the requirement of mega low earth orbit (LEO) constellation design in non-terrestrial network (NTN), a geometric configuration design method of Walker constellation applicable to arbitrary latitude range coverage multiple and satellite quantity scale is proposed. First, a Walker configuration representation based on the streets of coverage (SoC) characteristic parameters is proposed. Then, satellite quantity required for coverage and the SoC parameters are estimated by calculating the width and adjacent spacing of SoC, which can improve the enumeration efficiency. Finally, by adjusting the phase and quantity of the satellite on the SoC, the constellation configuration with optimal comprehensive performances is selected from multiple groups of results. To demonstrate the effectiveness of the proposed design method, the performance comparisons among the existing mega LEO constellation systems are conducted. Compared with the existing configurations, the configuration calculated by the proposed method can efficiently reduce the satellite quantity required for coverage by about 20%, and can also satisfy the comprehensive demands including coverage performance, inter-satellite link, configuration redundancy and collision avoidance by reasonably selecting configuration parameters.

Multi-Layered Satellite Communications Systems for Ultra-High Availability and Resilience

Satellite communications systems provide a means to connect people and devices in hard-to-reach locations. Traditional geostationary orbit (GEO) satellite systems and low Earth orbit (LEO) constellations, having their own strengths and weaknesses, have been used as separate systems serving different markets and customers. In this article, we analyze how satellite systems in different orbits could be integrated together and used as a multi-layer satellite system (MLSS) to improve communication services. The optimization concerns combining the strengths of different layers that include a larger coverage area as one moves up by each layer of altitude and a shorter delay as one moves down by each layer of altitude. We review the current literature and market estimates and use the information to provide a thorough assessment of the economic, regulatory, and technological enablers of the MLSS. We define the MLSS concept and the architecture and describe our testbed and the simulation tools used as a comprehensive engineering proof-of-concept. The validation results confirm that the MLSS approach can intelligently exploit the smaller jitter of GEO and shorter delay of LEO connections, and it can increase the availability and resilience of communication services. As a main conclusion, we can say that multi-layered networks and the integration of satellite and terrestrial segments seem very promising candidates for future 6G systems.

Digital Twin Technology-Based Networking Solution in Low Earth Orbit Satellite Constellations

Digital twin technology provides a reliable paradigm to address the high trial-and-error costs and limited perception capabilities in satellite networking. However, the dynamic constellation topology and real-time twin applications remain significant challenges in satellite network design. This paper proposes a network topology simulation approach that dynamically analyzes the inter-satellite topology based on pre-calculated ephemeris and orbital information. Furthermore, the paper introduces a digital twin algorithm based on network virtualization, cloud platform management, and software-defined networking to validate and analyze the twin requirements at different stages. Finally, a low Earth orbit (LEO) constellation twin validation environment is constructed to verify the networking protocols at various stages. The experimental results demonstrate the performance of the proposed twin systems at different stages.

Gravity field recovery of inter-satellite links between Beidou navigation satellite system (BDS) and LEO based on geodesy and time reference in space (GETRIS)

The goal of this contribution is to construct the inter-satellite links (ISLs) between Global Navigation Satellite System (GNSS) and Low Earth Orbit (LEO) satellite to recover the Earth’s gravity field based on the concept of Geodesy and Time Reference in Space (GETRIS). Taking the constellation of the Beidou Navigation Satellite System (BDS) as an example, several types of high-low satellite-to-satellite tracking (H-L SST) modes combining BDS and GETRIS are used to research the tracking mode of high orbit satellites and the distribution of LEO satellite constellations to explore the optimal mode for gravity field recovery. The effects of multiple H-L SST modes on the accuracy of gravity field recovery are studied. In addition, the contribution of each error source is also analyzed. Finally, this study varies LEO satellite constellations to show reduced errors in the temporal gravity field solutions for the improved ISLs. The results showed that the Inclined GeoSynchronous Orbit (IGSO) satellite greatly improved the Geosynchronous orbit (GEO) satellite tracking LEO satellite mode in the high latitude regions. Compared with the Medium Earth Orbit (MEO) satellite tracking LEO satellite, the error of gravity field recovered by combining with GEO, IGSO and MEO can be reduced by 16 %. The largest error is the non-tidal signal, followed by the ocean tidal model difference, and the smallest is the instrument error. For a single LEO satellite, the combination model is more sensitive to the satellite orbital altitude, the cumulative error was decreased from 5.08 mm (550 km) to 0.33 mm (250 km). For LEO constellations, adding inclined orbit satellites can improve the accuracy of the solution to some extent. But the optimal solution can be obtained by the constellation composed of polar orbit satellites with different Right Ascension of Ascending Node (RAAN), the cumulative errors are 0.27 mm (two satellites), 0.19 mm (three satellites), and 0.19 mm (four satellites).

LEO Satellite Downlink Distributed Jamming Optimization Method Using a Non-Dominated Sorting Genetic Algorithm

Due to their low orbit, low-Earth-orbit (LEO) satellites possess advantages such as minimal transmission delay, low link loss, flexible deployment, diverse application scenarios, and low manufacturing costs. Moreover, by increasing the number of satellites, the system capacity can be enhanced, making them the core of future communication systems. However, there have been instances where malicious actors used LEO satellite communication equipment to illegally broadcast events in large sports stadiums or engage in unauthorized leakage of military secrets in sensitive military areas. This has become an urgent issue in the field of communication security. To combat and prevent abnormal and illegal communication activities using LEO satellites, this study proposes a LEO satellite downlink distributed jamming optimization method using a non-dominated sorting genetic algorithm. Firstly, a distributed jamming system model for the LEO satellite downlink is established. Then, using a non-dominated sorting genetic algorithm, the jamming parameters are optimized in the power, time, and frequency domains. Field jamming experiments were conducted in the southwest outskirts of Xi’an, China, targeting the LEO constellation of the China Satellite Network. The results indicate that under the condition that the jamming coverage rate is no less than 90%, the proposed method maximizes jamming power, minimizes time delay, and minimizes frequency compensation compared to existing jamming optimization methods, effectively improving the real-time jamming performance and success rate.

Optimizing the Deployment of Ground Tracking Stations for Low Earth Orbit Satellite Constellations Based on Evolutionary Algorithms

Low Earth orbit (LEO) satellite constellations have emerged as an effective alternative for the provision of high-accuracy positioning, navigation and timing (PNT) solutions which are based on high-precision orbit and clock information. Determining an orbit with high precision is dependent on the number and distribution of ground tracking stations. Therefore, it is important to investigate methodologies that can ensure the adequate observing coverage of LEO navigation constellations. In this study, an evolutionary algorithm is applied to optimize the number and deployment of ground stations for tracking LEO constellations. According to the distribution area, two schemes of study are analyzed: (a) global deployment—the ground stations are deployed throughout the globe; (b) regional deployment—a selected region is used for deployment. For global deployment, the optimization objectives are focused on the ground station and observing rate for k-heavy observing coverage (HC), while the sole objective for the regional deployment scheme is the satellite position dilution of precision (SPDOP). It is shown that a deployment of 95 ground stations is optimal for achieving 3-HC with an observing rate of 97.37% and 4-HC with an observing rate of 92.01%. For regional distribution, 15, 20 and 25 ground stations are used for three optimal configurations of SPDOP at 2.058, 1.399 and 1.330, respectively. The results are significantly enhanced using intersatellite links for SPDOP evaluation, from 2.058, 1.399 and 1.330 to 0.439, 0.422 and 0.409, with 15, 20 and 25 ground stations, respectively.

Transformer-based anomaly detection in P-LEO constellations: A dynamic graph approach

Successful management of large space systems, such as the most recent Proliferated Low Earth Orbit (P-LEO) constellations, demands an increased level of autonomy and irregular behavior detection capability. Existing techniques for satellite network management rely on monitoring satellites individually, potentially failing to capture events shared across multiple units. In this work, we propose a pipeline for identifying anomalous connections in proliferated satellite networks. Our pipeline relies on representing a satellite constellation as a dynamic graph. Dynamic graphs can be conveniently exploited to represent P-LEO networks, as they allow to capture meaningful structural and temporal correlations. Such spatial and temporal information are first projected into an embedding space; next, this encoded representation is processed by a transformer-encoder network for the anomaly detection task. We conduct extensive analyses of the main problem parameters, including the temporal horizon, the structure of the graph, and the size of the constellation. To assess the general performance of the method, we perform a Monte Carlo analysis on 960 ground node pair connections, providing empirical evidence of the algorithm’s generalization capability. The obtained results encourage the extension of the method to more complex, realistic modeling and kindred applications such as the on-edge detection problem.

Doppler effect‐based low‐Earth orbit satellite constellation parameters

AbstractThe present study focuses on the manifestation of the Doppler effect in low‐Earth orbit (LEO) satellite constellations with laser inter‐satellite links (LISLs). In this letter, the LEO satellite constellation parameters that influence the variation of the Doppler effect in LISLs are presented. The LEO satellite constellation configurations that perform LISLs with less possible Doppler effect could be designed based on the tendency of the Doppler wavelength shift (DWS) as a function of the LEO satellite constellation's parameters. The paper presents the main LEO satellite constellation parameters that involve the variation of the Doppler effect, such as the altitude of the satellites, the orbital plane number within the constellation, and the inclination angle of the orbital plane. In addition to the operating laser wavelength that is employed as a data carrier. These parameters could be helpful to control the Doppler effect in LISL before building an LEO constellation.