History of EISCAT – Part 5: Operation and development of the system during the first two decades

• Main Author: Wannberg, Gudmund
• Format: Text
• Language: English
• Published: 2021
• Subjects: Eros; Kiruna; Sodankylä; Tromsø; EISCAT
• Online Access: https://doi.org/10.5194/hgss-2021-16; https://hgss.copernicus.org/preprints/hgss-2021-16/

This paper gives an inside view of the first 20 years of operation of the Kiruna-Sodankylä-Tromsø (KST) part of EISCAT as experienced and remembered by myself. The paper is subdivided into an Introduction and 13 sections. Sections 1 to 6 describe the organization, staffing and responsibilites of the Sites, with particular emphasis on the transmitter-related work at Tromsø and the commuting of staff and equipment between the Sites. The Headquarters operation is treated in Section 7. The UHF radar system is treated in Section 8. Section 9 is a review of the VHF system, including a summary of transmitter and antenna problems not available elsewhere in easily accessed media. Section 10 treats the computer system and the proprietary control languages EROS, TARLAN and CORLAN. Section 11 describes the signal processing hardware, with special emphasis on the Alker correlator, its idiosyncrasies and the gradual unlocking of its capabilities through UNIPROG, the GEN-system and the G2-system, culminating in the ability to run alternating codes experiments routinely. Section 12 presents the time- and frequency keeping, a non-trivial task in the early 1980s. Finally, Section 13 discusses the UHF spectrum problem and relates how the UHF system had to be constantly upgraded in order to be able to co-exist with the emerging cellphone networks until the final closure of UHF reception at Kiruna and Sodankylä in 2012. The paper ends with some personal reflections.