DTU has undertaken the ESA project “DTU-ESA Coordinated Antenna Laboratory Performance Upgrade” with the objective of upgrading the performance of the DTU-ESA Spherical Near-Field Antenna Test Facility for high-accuracy testing of space-technology antennas. This upgrade included central instruments of the measurement system; one instrument is the theodolite used for mechanical alignment of the antenna and probe positioners, as well as the antenna under test, while the other instruments form an integrated part of the RF and data acquisition system.
The procurement process conducted in 2018 was based on the Requirement Specification Document and the System Specification Document. The installation of the theodolite from Leica Geosystems took place in December 2018 in parallel with the installation of the new probe positioner top table, developed in-house at DTU as part of the 2017-2018 upgrade of building 353 housing the DTU-ESA Facility. The installation of the instruments from NSI-MI for the RF and data acquisition system took place in January 2019.
During the installation in January 2019, a series of acceptance tests were conducted to assess the functionality of the new instruments/system. These acceptance test successfully demonstrated that instruments are working correctly, that instruments are connected correctly, that the data acquisition, including the triggering functions, are working correctly, and that measurement data are in the correct format for processing.
A first full-scale measurement took place in February- March 2019; this concerned L-band, low-gain satellite communication and navigation antennas.
A second full-scale measurement took place in May 2019; this concerned L-band antenna elements of the SMOS-IRMI remote sensing antenna system.
Though these 2 measurement projects are not formally part of the present project, their successful completion contributes to demonstrating that the new measurement system is operational.
The formal validation of the operational capability of the new MI-750 system and the new measurement procedure was based on the Validation Test Campaign which comprised 4 Antennas Under Test at 4 frequencies. The results were compared with results from corresponding measurements with the previous MI-1797 system. The 4 validation measurements were conducted between March 2019 and November 2019.
The antennas for the 4 validation measurements are summarized in the following table.
No.󠄡󠄡󠄡󠄡󠄡󠄡󠄡󠄡.....Centre Freq.....Antenna Under Test
..........1.......0.435 GHz.......Satimo SH-400 dual-ridged horn
..........2.......5.355 GHz.......DTU KRAS slotted-waveguide array
..........3.......12.00 GHz.......DTU-ESA 12 GHz Validation Standard antenna
..........4.......48.16 GHz.......DTU-ESA mm-VAST antenna
Besides some minor issues, to be solved as regular maintenance, it was concluded that the DTU-ESA Spherical Near-Field Antenna Test Facility was succesfully upgraded and is operational with the new equipment and procedures.
|ESA Technical Officer||Maurice Paquay|