Validation of the radiation pattern of the Middle Atmosphere Alomar Radar System (MAARSY)

T Renkwitz,R Latteck,W Singer,G Stober,M Rapp

doi:10.5194/ars-10-245-2012

Abstract

Abstract. In 2009/2010 the Leibniz-Institute of Atmospheric Physics (IAP) installed a new powerful VHF radar on the island Andøya in Northern Norway (69.30° N, 16.04° E). The Middle Atmosphere Alomar Radar System (MAARSY) allows studies with high spatial and temporal resolution in the troposphere/lower stratosphere and in the mesosphere/lower thermosphere of the Arctic atmosphere. The monostatic radar is operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output of up to 2 kW, which implies high flexibility of beam forming and beam steering. During the design phase of MAARSY several model studies have been carried out in order to estimate the radiation pattern for various combinations of beam forming and steering. However, parameters like mutual coupling, active impedance and ground parameters have an impact on the radiation pattern, but can hardly be measured. Hence, experiments need to be designed to verify the model results. For this purpose, the radar has occasionally been used in passive mode, monitoring the noise power received from both distinct cosmic noise sources like e.g. Cassiopeia A and Cygnus A, and the diffuse cosmic background noise. The analysis of the collected dataset enables us to verify beam forming and steering attempts. These results document the current status of the radar during its development and provide valuable information for further improvement.

Highlights

In this manuscript we present a recent study with the main aim to validate the receiving system of the Middle Atmosphere Alomar Radar System (MAARSY) VHF radar by observing cosmic radio noise
We analyzed experiments which have been performed to verify the beam pointing and beam forming of the MAARSY VHF radar
We verified the beam pointing and beam forming of the MAARSY radar and estimated the accuracy of beam pointing to be better than 0.5◦ in azimuth and zenith angle

Summary

Introduction

In this manuscript we present a recent study with the main aim to validate the receiving system of the MAARSY VHF radar by observing cosmic radio noise. The radiation pattern may be affected by e.g. mutual coupling of the antennas and active impedances This implies the necessity of experimental methods to verify the model results. Czechowsky et al, 1984; Palmer et al, 1996; Zecha, 1999; Campistron et al, 2001; Carey-Smith et al, 2003; Fukao et al, 2003; Swarnalingam et al, 2009a,b; Renkwitz et al, 2011) The purpose of these studies has been e.g. to derive the apparent noise contribution for a given sidereal time at the receiver system, to verify the beam pointing of the antenna array, or to estimate the beam pattern itself as a process of calibration. We will present a comparison of our observations with a global sky model which is based on several cosmic noise surveys

Experiment description

Validation of the radar beam position and beam width

Comparison of a single day data set of observations with a global sky model

Findings

Summary and conclusions