Update on 460-470 MHz Band for CubeSat High Speed Data Downlink Fall 2010 AGU Side Meeting Thursday Dec 16, 2009 Charles Swenson
Review 460-470 MhZ Band Image courtesy of http://si.smugmug.com/gallery/1674201_uxzmp/1/457184513_4s3ag We are limited by regulations and not technology for CubeSat downlinks. AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 2
NTIA Red Book Table on 460-470 MHz Must read the notes Lower case means secondary user AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 3
Definitions Earth Exploration-Satellite Service: A radio communication service between earth stations and one or more space stations, which may include links between space stations, in which: information relating to the characteristics of the Earth and its natural phenomena including data relating to the state of the environment is obtained from active sensors or passive sensors on earth satellites; similar information is collected from active sensors or passive sensors on Earth satellites: airborne or earth-based platforms; such information may be distributed to earth stations within the system concerned; platform interrogation may be included. This service may also include feeder links necessary for its operation. Meteorological-Satellite Service: An Earth exploration-satellite service for meteorological purposes. AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 4
Regulations on 460 to 470 MHz 5.289 Earth exploration-satellite service applications, other than the meteorological-satellite service, may also be used in the bands 460-470 MHz and 1690-1710 MHz for space-to-earth transmissions subject to not causing harmful interference to stations operating in accordance with the Table. US201 In the band 460-470 MHz, space stations in the Earth exploration-satellite service may be authorized for space-to-earth transmissions on a secondary basis with respect to the fixed and mobile services. When operating in the meteorological-satellite service, such stations shall be protected from harmful interference from other applications of the Earth exploration-satellite service. The power flux-density produced at the Earth s surface by any space station in this band shall not exceed -152 dbw/m²/4 khz. AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 5
Existing E-S Users in this band GOES Data Collection Platform Interrogation (DCPI) Systems Provides a Control link to weather stations around the world Conforms to -152 dbw/m²/4 khz flux limit AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 6
DICE Telemetry Systems (1.5 Mbit/s) db Gain 1.56 1.39 1.18 0.91 0.52-3.5 AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 7
DICE Spacecraft DICE: 824 x 350 km 102º Inc orbit with a 10:30 local-time descending node. 10 m tip-tip AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 8
DICE ORBIT LIFE TIME & Telemetry contact Dice on orbit collection rates High rate 11 kbits/s Low rate 4.5 kbits/s DICE Simulated with STK Lifetime 3.3 years Contacts with Wallops Required 0.8% High data rate collect 0.4% Low data rate collect Significant Margin Higher orbit than conceived SRI & Wallops ground Stations Requirement Level AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 9 9
IRIG 106-99 Appendix A 3 db power difference OQPSK vs Uniform Range and Flux db/m 2 350 km results in -121.9 db 824 km results in -129.3 db US201 Red Book Note: In the band 460-470 MHz... The power flux-density produced at the Earth s surface by any space station in this band shall not exceed -152 dbw/m²/4 khz. DICE PSD Study AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 10 10
DICE Subsystems in integration and test Science Calibration Electronics Integration Chassis w/ Antenna Inte AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 11 11
Wallops Ground Station Physical Layout RF WBX USRP2 Ethern et PC GnuRadio AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 12
Stage 3 Completed and submitted to NSF Informal Discussions with NTIA Positive Working on information for Stage 4 with L-3 and as part of I&T Testing Licensing Status AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 13
Needed to get to Stage 4 (final) Satellite Receiver Need receiver noise temperature or noise figure. (Enter on Emission- Sensitivity screen) Need Image Rejection Level in db. Need RF selectivity curve. Need receiver sensitivity Need IF selectivity curve including 3, 20, and 60 db points. Indicated measured or calculated. Need Performance Criteria (BER, MDS, PWOP, SINAD, (S+N)/N, S/N, Other) Need Performance Value Need Spurious Rejection Level Db Conducted Undesired Emissions Local Oscillator Tuned Indicator Ground Station Receiver Need Image Rejection Level Need receiver sensitivity Need IF selectivity curve Need Performance Criteria (BER, MDS, PWOP, SINAD, (S+N)/N, S/N, Other) Need Performance Value Need Spurious Rejection Level db Conducted Undesired Emissions Ground Station Transmitter Need Spurious Emission Level Need 2 nd and 3 rd Harmonics level. Need Spurious emission curve Need Harmonic curve. Need RF emission bandwidth curve. AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 14
ISS Jettison Policy (PDD1011) AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 15
Kibo Concept 198 Units of CubeSats Side Deploy 120 Units of CubeSats End Deploy Ram Side Deploy AGU Side meeting on high speed data downlinks for CubeSats (12/16/2009) 16