Summary of RFI Data Samples at Green Bank

Rick Fisher, NRAO, Green Bank, WV

Contents

Introduction

This web page is a brief summary of data files that contain samples of signals seen at the NRAO observing site at Green Bank, WV, USA. Many of these signals are transmissions for valuable commercial or government purposes such as communications and radio navigation, but to the radio telescopesd at Green Bank they are seen as radio frequency interference (RFI) covering up weal radiation from celestial radio sources. The main intent of these data samples is to aid engineering research into ways of separating man-made from cosmic signals.

Radar at 1292 MHz

In afternoon of February 6, 2001 a 10 MHz passband centered on 1293 MHz from the GBT's 1.15-1.7 GHz receivers was sampled at baseband with the Signatec PDA500 data acquisition board. This passband contains an air surveillance radar signal with a nominal carrier frequency of 1292.01 MHz. The radar pulse sequence is randomly selected with an average repetition rate of 341 Hz and a pulse width of 2 microseconds. The radar antenna sweep period is about 12 seconds per rotation, and the beamwidth is about 1 degree. The RADAR antenna is about 138 km south-southeast of Green Bank at an azimuth of about 168 degrees. For data files were recorded. All contain 8-bit A/D data samples of baseband voltages from the GBT receiver. Zero voltage has a value of roughly 128, but there may be a zero offset of a few counts. The receive white noise spans
Last modified February 8, 2001

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