Abstract The tracking and data relay satellite (TDRS) in geosynchronous orbit (GEO) can provide ranging communication services for user spacecraft low Earth (LEO) through the inter‐satellite link (ISL). time delay of TDRS ISL transponder differs from its pre‐launch state changes due to complex space environment, adding significant errors spacecraft's determination based on four‐way data. author...

Abstract The differential code biases (DCBs) of the global positioning system (GPS) receiver onboard low-Earth orbit (LEO) satellites are commonly estimated by a local spherical symmetry assumption together with known GPS satellite DCBs from ground-based observations. Nowadays, more and LEO equipped receivers for precise determination, which provides unique chance to estimate both without any g...

In this article, we investigate the issue of massive access in a beyond fifth-generation (B5G) multibeam low-Earth orbit (LEO) satellite Internet-of-Things (IoT) network presence channel phase uncertainty due to channel-state information (CSI) conveyance from devices via gateway. Rather than time-division multiple (TDMA) or frequency-division (FDMA) with multicolor pattern, new nonorthogonal (N...

Autonomous, anti-jamming, and high-precision satellite navigation are of great importance to current future space technologies. This paper proposes a cooperative constellation system for low Earth orbit (LEO) satellites that use only the optical measurements satellites. Based on photometry, an transmission link model is built. With pixel coordinates images, line sight (LoS) vectors with respect...

Due to the short revisit time and large coverage of Geosynchronous synthetic aperture radars (GEO SARs) increasing number low earth orbit radar (LEO SAR) constellations, radio frequency interference (RFI) between GEO SARs LEO may occur, deteriorating quality SAR images. Traditional methods only simplify RFI noise-like without considering signal characteristics. In this paper, accurately evaluat...

lation study for the evaluation in low earth orbit (LEO) ellations, used for the of high-speed networks, is paper. The proposed model end the traffic process at the supporting successfully the f self-similar traffic sources , ach that has been considered an the well-known Poisson, munications. dy for the establishment of s (ISLs) and the design of the ace segments is presented and of the integr...

To meet an increasing demand for multimedia services and electronic connectivity across the world, satellite networks will play an indispensable role in the deployment of global networks. A number of satellite communication systems have been proposed using geosynchronous (GEO) satellites, medium earth orbit (MEO) and low earth orbit (LEO) constellations operating in the Ka-band and above. At th...

On-orbit servicing (OOS) presents new opportunities for refueling, inspection, repair, maintenance, and upgrade of spacecraft (s/c). OOS missions s/c in a geostationary orbit (GEO) are currently underway. However, there no plans low-Earth-orbit (LEO) s/c, aside from technology demonstrations, because their shorter design life lower cost. Designing systems LEO constellations differs that GEO-bas...

Continued growth in the orbital debris population has renewed concerns over the long-term use of space. Debris poses an increasing risk to manned space missions and operational satellites; however, the majority of debris large enough to cause catastrophic damage is not being tracked and maintained in a catalog. Passive optical systems hold great promise to provide a cost-effective means to moni...

Microwave occultation using centimeter and millimeter wave links between low Earth orbit (LEO) satellites provide a potential way to estimate the moist atmospheric profiles based on refraction attenuation measurements, which is called LEO-LEO microwave (LMO) technique. It has not yet been implemented in orbit. In this paper, we analyzed properties at different heights of waves simulations. The ...