Plot showing an example of errors in estimates of thermospheric density derived using a range of different models.
An example of errors in estimates of thermospheric density derived using a range of different models: (a) the two largest errors arise from use of two existing thermospheric models (NRLMSISE-00 and JB2008), whilst (b) smaller errors arise from assimilation into the authors’ reduced-order model (ROM) using data derived from GPS tracking on-board satellites and to satellite orbit data (two-line elements, TLE) derived from radar tracking. The errors are expressed in terms of daily-averaged density and as percentage of true density along the SWARM A orbit during the month of May 2020. Credit: Gondelach et al. [2021], Figure 6 left panel
Source: Space Weather

Modern societies are critically dependent on the safe operation of satellites, including reliable forecasts of satellite location and avoidance of collisions. Gondelach et al. [2021] is an excellent example of how better assessment of space weather conditions, in this case thermospheric density, can contribute to that safety. The authors present an improved scheme for estimating thermospheric density in real-time using satellite tracking data both from ground-based radars and on-board GNSS receivers. This is an important step towards better management of space traffic in the low orbits (under 800 kilometers) where space-weather-driven changes thermospheric drag are a significant source of uncertainty in forecasts of satellite location and collision risks. The paper highlights that space weather is a significant element in the emerging discipline of space traffic management.

Citation: Gondelach, D. J., & Linares, R. [2021]. Real‐time thermospheric density estimation via radar and GPS tracking data assimilation. Space Weather, 19, e2020SW002620.

—Michael A. Hapgood, Editor, Space Weather

Text © 2021. The authors. CC BY-NC-ND 3.0
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