Receiving Ground Station

Receiving Ground Station The Alaska Satellite Facility (ASF) was conceived by NASA’s Polar Programs science community and is operated by the Geophysical Institute of the University of Alaska Fairbanks. ASF is both a member of the DAAC (Distributed Active Archive Center) Alliance and a NASA/NOAA Ground Network Station. In addition, ASF is the data acquisition Order Desk for all non-commercial U.S. customers for RADARSAT-1 and ERS-2 data. ASF archives SAR data in accordance with International MOU’s, processes multiple levels of data products, distributes data products to a diverse, non-commercial user community and provides user tools specific to ASF’s data. The highly trained consultants in the User Services Office strive to ensure customer statisfaction. As a ground station, ASF operates two tracking stations, a 10m X-band and an 11m X- and S-band system. Each tracker is capable of three (3) simultaneous channels from polar-orbiting spacecraft. ASF is currently servicing three satellites on a 24/7 basis: Canadian Space Agency’s (CSA) RADARSAT-1, European Space Agency’s (ESA) ERS-2, and National Space Development Agency of Japan’s (NASDA) ADEOS-2.

RGS 10m Tracking System

* ASF Station mask for ADEOS-2, ERS-2, and RADARSAT-1

X-Band Receiving System

• Latitude - 64 deg 51 min 35.6797 sec N, NAD27 • Longitude - 147 deg 50 min 50.2500 sec W, NAD27 • Elevation at feed - 758 ft msl • 10m aperture, Cassegrain feed with S-Band feed at prime focus, X-Band feed at Cassegrain focus • 3316 three-axis pedestal with 2.5 deg tilt axis • 3842 antenna controller • Computerized, full hands-off pass support capability • No capability for S-Band uplink at this time, but could be added as required • 924-1-2 Wideband Demodulators supporting 924-2 multichannel Bit Synchronizers

X-Band telemetry system G/T - 32 dB/deg K Three independent, separately-tuned data channels • RHC & LHC selectable for all data channels as a group • Freq Range 8025-8400 MHz (in 200KHz) increments) • QPSK/UQPSK • Bit synch/Signal conditioner support for: 105 Mbps QPSK [ERS-2 & RSAT] 100 Mbps QPSK [Envisat] 85 Mbps QPSK [RSAT] 60 Mbps QPSK [ADEOS 2] 6 Mbps QPSK [ADEOS 2] Tracking channel, pseudo-monopulse autotrack mode

S-Band Receiving System S-Band telemetry system G/T - 21 dB/deg K Tracking channel, pseudo-monopulse autotrack mode No active data channels at this time, but capability could be added easily

10m antenna on the Geophysical Institute

ASF Receiving Ground Station

RGS 11.28m Tracking System • Latitude - 64 deg 51 min 32.9280 sec N, NAD27 • Longitude - 147 deg 51 min 18.5250 sec W, NAD27 • Elevation at feed 672 ft msl • 11.28m aperture, Cassegrain feed with S-Band feed at prime focus, X-Band feed at Cassegrain focus • 3316 three-axis pedestal with 7 deg train axis • 3860 antenna controller • Computerized, full hands-off pass support capability • Tracker command uplink capability has been installed • 924-1-2 Wideband Demodulators supporting 924-2 multi-channel Bit Synchronizers

X-Band Receiving System

View of ASF’s 11m antenna

S-Band Receiving System S-Band telemetry system G/T - 22 dB/deg K Dual-polarization diversity combiners supporting data and track channel • Freq Range 2200-2400 MHz • Demods for AM, PM, FM, & BPSK • Data Rates - 10 kbps to 4 Mbps BIO-L, 10kbps to 8 Mbps NRZ-L Tracking channel, E-Scan autotrack mode

S-Band Uplink System • Freq Range 2025-2120 MHz • Power range 50 to 200 watts • Modulation: Transmit Data - 2kbps data BPSK on a 16 kHz subcarrier, linearly PM on uplink Transmit Ranging - 1.7 MHz subcarrier summer with data

Updated September 2003

X-Band telemtry system G/T - 34 dB/deg K Four independent, separately-tuned data channels • RHC &LHC selectable for all data channels individually • Freq Range 8000-8500 MHz (in 100 KHz increments) • QPSK/UQPSK • Bit synch/Signal conditioner support for: 105 Mbps QPSK [ERS-2 & RSAT-1] 85 Mbps QPSK [RSAT-1] 60 Mbps QPSK [ADEOS-2] 6 Mbps QPSK [ADEOS-2] Tracking channel, pseudo-monopulse autotrack mode

Digital Recording Capability X-Band - any data channel from either tracker to multiple data sinks, fully automated at time of pass scheduling, complete hands-off during acquisition • Sony ID-1, High-Density Digital Recorder, all data rates supported by bit synchs • Ampex DCRSI, all data rates supported by bit synchs • Direct Capture System (DCS) - 4 channel direct capture to disk at up to 150 Mbps • Programable Telemetry Processor (PTP) providing direct capture to disk for S-Band downlink

Contact Information Alaska Satellite Facility UAF Geophysical Institute P.O. Box 757320 Fairbanks, Alaska USA 99775-7320

Phone: 907-474-6166 Fax: 907-474-2665 E-mail: [email protected] Web site: www.asf.alaska.edu