lewis

Slide1: 

RFI in the alpha band pass Murray Lewis N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Senior Research Associate Radio Astronomy Group

Propose to cover: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Propose to cover FCC frequency allocations in spectral region GPS Galileo PR Radars in band RFI Mitigation possibilities radar blankers! nine level sampling! algorithms! cross correlation between feeds Reinforcement of AO anti-RFI activity!

Slide3: 

The frequency range covered by alpha is from 1225 to 1525 MHz N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R

Slide4: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R

Slide6: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R

GPS L1, L2, L5: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R GPS L1, L2, L5 L5 L2 L1 General coverage -158 dBW Spot Beam -138 dBW Alpha 1225 - 1525

GPS: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R GPS L1 & L2 -157 dBW for C/A -160 dBW for Y L5 -154 dBW ≈24 MHz, full time occupancy This is 6dB stronger than present L1 & L2 L5 spfd ~-205 dBW/m^2/Hz 1164-1188 MHz ~-197 dBW/m^2/Hz in center 5 - 8 satellites always available Also, of concern, GPS L3 circa 1381 MHz

Galileo -- full set due 2008: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Galileo -- full set due 2008 E5A_E5B 1164-1215 MHz (WRC2000) E6 1260-1300 MHz (WRC2000) E2,L1,E1 1559-1591 MHz Use of C_band under consideration To have 30 satellites, in 3 planes, inclination 56 deg 14 hr orbits, radius 23616 km Power 50 W amplifiers peak power 120 W

Galileo: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Galileo On orbit validation 2001-5 2/4 satellites Deployment 2006-7 26-28 sats Commercial Ops. 2008 Concern is their presence at 1260-1300 MHz

Slide11: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Details of Common/Unusual RFI Available on AO Web Page

Hilltop Monitor 1200-1450 MHz: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Hilltop Monitor 1200-1450 MHz

Slide13: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Blanking San Juan Airport Radars? Examples Surroundings of 1400-1427 MHz band US has proposed a satellite system Uplink circa 1400, downlink circa 1427 MHz Timing explorer in Space Lab was at 1427 MHz L3 (GPS) at 1381 MHz

Fractional occupation of 0.1 MHz bins: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R Fractional occupation of 0.1 MHz bins

Slide15: 

N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R

Slide18: 

0 500 1000 1500 2000 0 500 1000 1500 2000 400 0 20 0 RATAN-500 1116+28

Slide19: 

Arecibo anti-RFI activity N A T I O N A L A S T R O N O M Y A N D I O N O S P H E R E C E N T E R importance of L_band to alpha Do you want radar blankers How bothersome is the 1350 MHz birdie? Should you be using 9-level sampling? Algorithm development