Survey and simulation of space debris using EISCAT UHF

This thesis starts with a review of the evolution of space debris, what is consists of, how it is made, how it is detected and tracked, and why it is such an important topic. Some of the worst collisions have contributed to causing 49% of the total space debris. If the launch rate continues, the "Kessler Syndrome" might become a reality destroying our future outlook for space communication and exploration. Furthermore, a deeper look at the contents is done and what is the impact of these hypervelocity objects. Highly-advanced ground surveillance systems are used to track and catalog the space debris stationed around the globe, and highly sophisticated space debris models are used to estimate the density of the total space debris population in all sizes, shapes and compositions. After 60 years in space, a lot of space debris has accumulated, resulting in a large increase of density in the polar regions. However, objects below 10 cm are not easily detected, but EISCAT UHF is capable detecting the sizes below 10 cm and down to 1 cm by using beampark experiments, its location makes it suitable for detecting polar region debris. The data is then used to confirm the catalog and the models. A 24-hour beampark experiment was done on 4th of January 2018 simultaneously at Tromsø and Svalbard, specifically for this thesis. It statistically measured the range, the Doppler velocity, and the echo strength of space debris. An inversion of apogee and inclination was then done by using these parameters. A modelling of a beampark experiment was simulated, propagating objects through the EISCAT UHF beam. It extracted the data from the ESA MASTER model and the output was the number of detections per day. A comparison of the beampark experiment 2018 campaign with the simulation model indicated that the simplified model shows good correlation with the observations

2018 Beam-park observations of space debris with the EISCAT radars

Source at https://conference.sdo.esoc.esa.int/proceedings/neosst1/paper/480.Monitoring the evolution of the space debris environment requires regular radar observations of the space debris population. This study presents the results from 24 hours of beam-park observations of space objects conducted simultaneously with the EISCAT Svalbard and Tromsø radars on and between January 4th and 5th, 2018. The measurements are processed with a new matched filter bank analysis program, which doubles the coherent integration time, and hence sensitivity, compared with the previous program. We observe 2077 objects with the Tromsø radar and 2400 objects with the Svalbard radar. The detections are correlated with the NORAD catalog. We find that 68% of the Tromsø and 85% of the Svalbard radar detections are from objects in the NORAD catalog, with most of the catalog object detections being in the side lobes of the radar antenna. The beam-park data are compared with a simulated beam-park experiment for catalog objects. The simulation uses a radar detection model that includes the effects of coherent integration and an antenna beam shape with side lobes. We find that the simulation agrees well with the measurements, indicating that the radar sensor response is accurately modeled. Our results highlight the importance of modeling antenna side lobes when analyzing beam-park measurements. Not taking taking into account side lobe detections can lead to an underestimation of radar cross-sections and an overestimation of population density

Survey and simulation of space debris using EISCAT UHF

This thesis starts with a review of the evolution of space debris, what is consists of, how it is made, how it is detected and tracked, and why it is such an important topic. Some of the worst collisions have contributed to causing 49% of the total space debris. If the launch rate continues, the "Kessler Syndrome" might become a reality destroying our future outlook for space communication and exploration. Furthermore, a deeper look at the contents is done and what is the impact of these hypervelocity objects. Highly-advanced ground surveillance systems are used to track and catalog the space debris stationed around the globe, and highly sophisticated space debris models are used to estimate the density of the total space debris population in all sizes, shapes and compositions. After 60 years in space, a lot of space debris has accumulated, resulting in a large increase of density in the polar regions. However, objects below 10 cm are not easily detected, but EISCAT UHF is capable detecting the sizes below 10 cm and down to 1 cm by using beampark experiments, its location makes it suitable for detecting polar region debris. The data is then used to confirm the catalog and the models. A 24-hour beampark experiment was done on 4th of January 2018 simultaneously at Tromsø and Svalbard, specifically for this thesis. It statistically measured the range, the Doppler velocity, and the echo strength of space debris. An inversion of apogee and inclination was then done by using these parameters. A modelling of a beampark experiment was simulated, propagating objects through the EISCAT UHF beam. It extracted the data from the ESA MASTER model and the output was the number of detections per day. A comparison of the beampark experiment 2018 campaign with the simulation model indicated that the simplified model shows good correlation with the observations

2018 BEAM-PARK OBSERVATIONS OF SPACE DEBRIS WITH THE EISCAT RADARS

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