Benedikt Reihs, LeoLabs, Inc.; Owen Marshall, LeoLabs, Inc.; Peter Todd Williams, LeoLabs, Inc.; Matthew Stevenson, LeoLabs, Inc.
Keywords: radar network, space surveillance, operational observations
Abstract:
With the steady increase in the number of objects in Low Earth Orbit (LEO), there is a simultaneously growing need for reliable information on those objects orbits. LeoLabs, Inc. is providing tracking data and collision avoidance services for satellite operators and state regulators to increase the safety of flight in LEO. Currently, the LeoLabs data is collected via 4 one-dimensional S-band radars at two locations in New Zealand and Costa Rica, and two UHF-radars in the United States of America, including the two-dimensional radar PFISR. To meet the growing demand and to provide tracking data for more objects and at a higher update frequency, LeoLabs is expanding their radar network over the next years by building additional S-band radar sites across the globe. Several more sites will become operational during the year 2022 and more instruments are in planning beyond that.
While building new radars is one aspect of the networks growth, the locations and field-of-view orientations of those radars have a significant impact on the improvements they provide for future data collection. To better understand these influences, various simulation tools have been developed. Those allow it to calculate and analyze all passes over a defined set of radar sites, which can also include for example the object size to get an estimate of the probability of detection.
With these simulation tools, various experiments have been run to cover three main aspects regarding the addition of new radar sites: (1) The increase in global observations per day for objects across all LEO. This is mainly driven by the number of sites and the orientations of their field-of-views. Based on this, it is also possible to estimate the increased performance in specific orbits of interest like densely populated polar orbits. This is of interest for example in the context of providing more data for high-risk conjunction events on a short notice. (2) The capability to detect new, formerly uncatalogued objects when such a new object passes through both field-of-views at the same site. In this case, an initial orbit is derived from all measurements, which can be used to schedule subsequent measurements. By simulating the regular tracking operations over a sufficiently long time, it can be statistically estimated what percentage of objects could have been discovered in different orbits with this process. (3) Launch and Early Operations (LEOP) support is used as an example of a special operations scenario. Having more radar sites with a better geographical distribution allows LeoLabs to analyze and select specific passes in such a case instead of using all available opportunities. The advantage of more radar sites would be to have more high-quality passes generating many measurements, shorter maximum time spans without good measurement data and less impact on regular tracking. A recent and representative example of a LEOP support will be shown to highlight this point.
The results will demonstrate the future performance of the LeoLabs radar network, which directly contributes to the safety of flight in LEO. These insights will also be used to strategically plan the additions of the next generation of radars and their locations regarding different optimization parameters.
Date of Conference: September 27-20, 2022
Track: SSA/SDA