The stare and chase observation strategy at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald: From concept to implementation

Daylight Measurement Acquisition of Defunct Resident Space Objects Combining Active and Passive Electro-Optical Systems

“…The impact of the observed orbital arc and the measurement type on orbit determination and improvement of defunct RSOs has been shown in [20]. Furthermore, studies focused on single-pass solutions varying the number and distribution of the observations within passes over the station at different culminations can be found in [21]. Note that we describe the length of the arc with respect to the revolution period.…”

“…To provide a better insight from the previous calculations, we show in Fig. 10 an example of the estimated apertures for both source and background, with the normalized intensity profile as a function of the estimated centroid (further details could be found in [8]). From the representation of the pointlike source on the image plane, we see in Fig.…”

“…The time synchronization of the two triggering starting events between the two systems is done via the Field-Programmable-Gate-Array device, which adds a short delay for the starting triggering signal on the passive device. Additional challenges were addressed when implementing the Stare and Chase observation strategy reported in [8]. The next case study shows an example of a RSO observed simultaneously by both systems during daylight.…”

“…In Fig. 13, we present in the top plot: coordinates in the camera reference frame (X cam and Y cam ), which are transformed into horizontal angles by the known transformation [8]; mid plot: the brightness as a by-product of the active tracking; bottom plot: the observed ranges minus the computed from the predictions acquired with the active system. We start the analysis by focusing on the results from the active tracking and the estimated changes in brightness.…”

“…Due to the narrow field of view available in current successful systems, the fact that we are targeting LEO RSOs, and that stars dimmer than an 8 apparent magnitude will not be easily discernible, the second option seems to be more attractive. The use of such a technique has been reported in [4], [8]. Laser beams of active electro-optical systems have fields of view of tens of arcseconds, requiring extremely accurate ephemerides that are currently not available for most RSOs.…”