Papers and Presentations by Bryan Klofas
Ground Station Engineer, Planet Labs
Electrical Engineering, Cal Poly State University
bklofas (at) gmail.com

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1. WVARA Meeting - February 2022
   • Presentation: 12 Grams Around The World: Picoballoons and Radiosondes. This talk is a bit higher-level than the Pacificon talk given late last year, with more background on why the SF-HAB group is interested in picoballoons. I gave this talk via zoom to the West Valley Amateur Radio Association, based in the Santa Clara Valley. Way back in high school, I took their amateur radio licensing class and was an active member in the club until I went off to college.
   • Recording: Audio recording of the talk.


2. Pacificon Convention - October 2021
   • Presentation: Picoballooning in the Bay Area: High Altitude Balloons, Picoballoons, and Radiosondes. Martin W6MRR, David WB6TOU, and I gave this presentation about our recent picoballoon and radiosonde activities with the SF-HAB group. The talk was well attended, and there were some great questions. Pacificon is our local ARRL Pacific Division annual convention held in San Ramon, California.
   • Video: Recording our talk on Youtube, taken and edited by Robert K6RGG.


3. SmallSat Conference - August 2020
   • Paper: Merging Diverse Architecture for Multi-Mission Support. Planet purchased the SkySat constellation from Google in 2017, and has slowly been integrating the two constellations since then. This paper, written with Kyle Colton, discusses the integration of the separate ground station networks, including hardware and software aspects. Software services are containerized on the ground station servers, which allows a single dish to download data from either satellite type on a per-pass basis. Special thanks to my coauthors Kyle Colton, Joseph Breu, Sydney Marler, Chad Norgan, and Matthew Waldram.
   • Presentation: Presentation given by virtually by Kyle Colton.


4. SmallSat Conference - August 2019
   • Paper: Planet High Speed Radio: Crossing Gbps from a 3U CubeSat. This paper, written with Kiruthika Devaraj, talks about Planet's new HSD2 X-band transmitter. This is our next generation high-speed transmitter, with data speeds up to 1.6 Gbps from LEO. Each channel of the six-channel system runs at 76.8 Msps, with three channels per X-band polarization. The transmitter outputs 2 watts of RF power with a total DC power draw of 50 watts. Special thanks to coauthors Kiruthika Devaraj, Matt Ligon, Eric Blossom, Joseph Breu, Kyle Colton, and Ryan Kingsbury.
   • Presentation: Presentation given by Kiruthika during the Communications Session of the 2019 SmallSat conference in Logan, Utah.


5. SmallSat Conference - August 2018
   • Open Source: OpenLST: An Open-Source Radio Solution. Planet is releasing the design for an open radio solution for communicating with remote instruments, vehicles, and stations using low-cost commercial components. OpenLST is based on the reference design for the CC1110 chip from TI, and over 300 of our CubeSats have flown a similar design in space. It's a project we've been working on at Planet for a few months. Included in this release is schematics, layout, and firmware, everything you need to get started with this project. Please note that you must git clone the repository, going there with your browser will not work.
   • Presentation: Presentation given by the team during the 2018 SmallSat conference in Logan, Utah.


6. SmallSat Conference - August 2017
   • Paper: Dove High Speed Downlink System. Written with Kiruthika Devaraj, Ryan Kingsbury, Matt Ligon, Joseph Breu, Vivek Vittaldev, Patrick Yeon, and Kyle Colton, this paper describes the high-speed downlink system for our Dove satellites. With the latest upgrades to 70 Msps DVB-S2 modulation up at 8.2 GHz, we are able to download up to 220 Mbps peak from our 3U CubeSats. This paper describes the entire Dove downlink system of downlinking pictures from the onboard storage to uploading them to the cloud. We are currently downlinking around 5 TB of picture data per day.
   • Presentation: Presentation given by Kiruthika Devaraj. I think the last slide is the most interesting, showing that most CubeSats are still downlinking data at under 10 Mbps. Other papers and presentations from this conference can be found on the SmallSat webpage.


7. CubeSat Developers Workshop - April 2017
   • Presentation: 88 Satellite Deployment and Frequency Licensing for Planet's Earth Imaging Constellation. This presentation gives a quick overview of the launch we just had from India, when 88 of our Dove satellites were deployed from a PSLV. The second half of the talk describes the licensing process we went through for our constellation, including pre-coordination among spectrum users, differences between Part 5 and Part 25 licenses, the dollar and time costs for a license, and license upkeep. Other presentations from this workshop can be found here, or use the custom Google search on the CubeSat Collaborate site.
   • Video: Video of the presentation. See presentations from the other days on the Cal Poly CubeSat YouTube channel.
   • Audio: Audio recording of the presentation.


8. SmallSat Conference - August 2016
   • Paper: Supporting the Flock: Building a Ground Station Network for Autonomy and Reliability. Written with my coworker Kyle Colton, this paper discusses the status of the Planet Labs ground station network, and how we perform automated fault detection and remote troubleshooting. With the recent launch of 12 satellites on the PSLV-C34 on June 22, 2016, our satellite constellation has grown to about 62 satellites, and we are downloading well over 1 TByte of imagery data per day.
   • Presentation: Supporting the Flock: Building a Ground Station Network for Autonomy and Reliability. Presented on August 10th. See the other papers and presentations from this conference on USU's Digital Commons site.
   • Article: Planet Preps Ground Network to Handle 5 Terabytes of Data Per Day. Caleb Henry from Via Satellite wrote a short article on our paper and presentation.


9. CubeSat Developers Workshop - April 2016
   • Presentation: Planet Labs Ground Station Network. As my first presentation working for Planet Labs, this presentation describes our ground station network. Currently we have 36 CubeSats in orbit, downlinking data to 18 sites around the world. On a typical day, we downlink 500 Gigabytes of picture data over our X-band system. Other presentations from this workshop can be found here, or use the custom Google search on the CubeSat Collaborate site.
   • Audio: Recording of the presentation above. You can view all the video recordings from this workshop here.


10. CubeSat Summer Workshop - August 2014
    • Presentation: CubeSat Communications Update. This presentation contains radio and frequency details of the latest CubeSats launched, including the Dnepr and PSLV-C23 launches in June 2014. Other presentations from this workshop can be found here or here, or use the custom Google search on the CubeSat Collaborate site.


11. CubeSat Developers' Workshop - April 2014
    • Presentation: High-Speed Radio Options. In this presentation, I give a brief overview of the high-speed radios presented at the CHDC meeting at Small Sat in August 2013. CubeSat sized flight-qualified radios are discussed, as well as future high-speed radios being designed and built by Canopus, University of Michigan, and NASA/JPL. Other presentations from this workshop can be found here.
    • Audio: Recording of the presentation above.


12. Ground System Architectures Workshop - February 2014
    • Presentation: CubeSat Radios: From kilobits to Megabits. This presentation gives a brief summary of the recent CubeSat launches, a survey of the communications systems of current CubeSats, and looks at current ground stations for low and high data rate comm systems. Future ground segments are discussed. This was presented in Session 9 of the Ground System Architectures Workshop (GSAW). Proceedings from this and earlier GSAW conferences can be found here.


13. AMSAT-NA Symposium - November 2013
    • Paper: Upcoming CubeSat Launches: The Flood Has Arrived. This paper discusses the 55+ CubeSats that will launched before the end of 2013, if all the launches happen on time. The upcoming launches include a Dnepr, Atlas V, ISS, and Minotaur 1. This paper is in the proceedings of the 2013 AMSAT-NA Symposium in Houston, Texas.
    • Presentation: Upcoming CubeSat Launches: The Flood Has Arrived. Associated presentation for the paper above. This presentation also adds four more CubeSat launches happening from December 2013 to April 2014, and brings the total number of CubeSats launched in the next six months to at least 100. This was presented in Houston, and other presentations from this conference can be found here.


14. CubeSat Developers' Workshop - April 2013
    • Paper: A Survey of CubeSat Communication Systems: 2009-2012. This is the next edition of my survey paper, and describes the comm systems of the CubeSats launched from 2009 up to the ELaNa-6/NROL-36 launch in September 2012. Detailed information about the radios, data rates, antennas, and ground stations is included. I also discuss the FCC-mandated transition from amateur satellite service to experimental service for US CubeSats.
    • Presentation: Survey of CubeSat Communication Systems: 2009-2012. This is the presentation based on the paper above. It includes some interesting pie charts showing that two-thirds of the CubeSats launched during this time period use 9600 baud data rates or less. We are still a low-data-rate community. This was presented at the 10th Annual CubeSat Developers' Workshop at Cal Poly. Other presentations from this workshop can be found here.
    • Audio: Recording of the presentation above.
    • Presentation: CubeSat Communication Systems 2003-2013: A Historical Look. Similar to the above presentation, but this presentation includes all of the CubeSats launched from the first launch in 2003 up to the PSLV-C20 launch in February 2013. This was presented at the Nanosatellite Ground Station Workshop, organized by JPL on Tuesday before the actual CubeSat Developers' Workshop.


15. AMSAT Symposium - October 2012
    • Paper: The Future of CubeSat Communications: Transitioning Away from Amateur Radio Frequencies for High-speed Downlinks. Written with Kyle Leveque, this short paper discusses current CubeSats that are using frequencies higher than the 437 MHz Amateur Radio Service for communications. Of the 77 CubeSats launched, only 17 CubeSats contain transmitters in this frequency range. Published in the 2012 proceedings of the AMSAT-NA Space Symposium in Orlando, Florida.
    • Presentation: The Future of CubeSat Data Communications. Updates to the paper with the latest CubeSat launch from the ISS in the beginning of October 2012, including the 5.84 GHz transmitter on FITSat-1. The rest of the presentations from this conference can be found here, or on the DVD sent to all AMSAT members in February 2013.
    • Audio: Audio recording of the talk, recorded by Dan Schultz.


16. CubeSat Developers' Workshop - April 2012
    • Presentation: CubeSat Frequency Allocation. This presentation describes the recent efforts on frequency allocation for the NSF-sponsored CubeSats. DICE and CINEMA have been coordinated through the NTIA, but it is unclear whether future NSF-sponsored CubSats should follow this route. The rest of the presentations from this conference can be found here.
    • Audio: Recording of the presentation above. You can view all the video recordings from this workshop here.


17. AMSAT Symposium - November 2011
    • Paper: Frequency Allocation for Government-funded CubeSats: NSF Paves the Way. Published in the proceedings of the AMSAT-NA Space Symposium in San Jose, California, this paper discusses frequency allocation and spectrum management for the current and future NSF CubeSats. NSF has successfully allocated two NSF CubeSats on government frequencies, and this paper documents the process that these CubeSats went through. Also discussed is the long-term goal of creating a new "small satellite" allocation for these low-power and short duration educational CubeSat missions.
    • Presentation: Frequency Allocation for Government-funded CubeSats: NSF Paves the Way. This presentation describes the paper, gives a brief background on all the current NSF CubeSats, and discusses their choices of frequency allocation. The rest of the presentations from this conference can be found here.


18. CubeSat Summer Workshop - August 2011
    • Presentation: CubeSat Communications Survey Update. This presentation is an update to my earlier paper about CubeSat Communication Subsystems. It discusses the comm systems of all 24 of the CubeSats launched since that earlier paper was published in fall 2008, including the 3 CubeSats on STP-S26 and the 8 CubeSats launched on the latest Falcon 9 launch. The rest of the presentations from this conference can be found here.
    • Video: See a video of this presentation on Ustream, part of all the videos streamed by the CubeSat Summer Workshop 2011 channel.


19. CubeSat Developers' Workshop - April 2011
    • Presentation: CubeSat High-Speed Downlink Communications Update. This presentation was given at the 8th Annual CubeSat Developers Workshop at Cal Poly. It's a status update on all the happenings with the NSF high-speed downlink group, including discussion about the long-term NSF effort to obtain a small slice of spectrum solely dedicated to CubeSat communications. The rest of the presentations from this conference can be found here.


20. CubeSat Developers' Workshop - April 2010
    • Presentation: CubeSat High-Speed Downlink Communications (CHDC) Update. This short presentation at the 7th Annual CubeSat Developers Workshop at Cal Poly gave a brief status update of the CubeSat High-Speed Downlink group. The presentation showed the current state of licensing for the NSF CubeSat project satellites. Also included are slides from Andy Clegg, Spectrum Coordinator for the NSF, which describes the NTIA licensing process. The rest of the presentations from this conference can be found here.
    • Video: See this presentation on Ustream.


21. AMSAT-NA Journal - November 2009
    • Paper: A Survey of CubeSat Communication Subsystems. This is a smaller version of my Comm paper presented at the 2008 Developers Conference at Cal Poly (see below). It only includes the latest CubeSat launch on the PSLV-C9 from India in April 2008. This was published in the November/December 2009 edition of The AMSAT Journal, a publication of The Radio Amateur Satellite Corporation.


22. AMSAT-UK Colloquium - July 2009
    • Presentation: CP6: T+2 Months and other thoughts. This presentation at the AMSAT-UK Colloquium talked a little bit about the status of CP6, and also described the NRL Payload, CPX Decoder, and survey results. The survey was given out to people using CPX Decoder, just to get a feel what equipment is being used to track CP6. The rest of the presentations from this conference can be found here.
    • Video: Watch a video of this presentation, courtesy of the British Amateur Television Club.


23. CubeSat Developers' Conference - April 2009
    • Presentation: CubeSat Thermal Environment Chamber. This presentation showed an easy way to build a thermal vacuum chamber for small payloads and CubeSats. It is designed to be very simple to construct, and uses all off-the-shelf products and minimal machining, perfect for universities on a tight budget. Karl van Dyk and Rick Doe, also at SRI International, helped with design and manufacturing of CTEC. The rest of the presentations from this conference can be found here.
    • Documents: CTEC files. Block diagrams, pictures, and parts list for the CubeSat Thermal Environment Chamber.


24. CubeSat Developers' Conference - April 2008
    • Paper: A Survey of CubeSat Communication Subsystems. I wrote this paper, along with Jason Anderson and Kyle Leveque, about all the different comm systems of CubeSats in orbit right now, including the radios used, modulation schemes, successes of each method, and the associated ground stations or ground station networks. It shows that very little data has been downlinked from the CubeSats currently in orbit, and provides some recommendations to future CubeSat developers about their communication subsystem.
    • Presentation: Survey of CubeSat Communication Subsystems. Presented during the Groundstation Operations section of the workshop. The rest of the presentations from this conference can be found here.


25. Senior Project - Spring 2008
    • Paper: Improving Receive Sensitivity of the CPX Bus. For my Senior Project, under the direction of Professor Dennis Derickson, I increased the receive sensitivity of the satellite by adding a LNA before the CC1000 receiver. We didn't have a LNA on our CP2 and CP3 satellites because we thought it wasn't necessary. The LNA is a Maxim MAX2640, and the bulk of the project was matching the LNA to the board. Both the LNA and board impedances will need to be tested.


26. AMSAT Symposium - October 2007
    • Paper: GENSO: A Global Ground Station Network. This paper outlines the GENSO theory of operation and goes in depth into how the different work packages interact. Cal Poly is part of Work Package J, tasked with Testing and Verification of the project. This paper was published in the conference proceedings. Graham Shirville G3VZV presented on my paper at the AMSAT Symposium in Pittsburgh, PA, on October 26, 2007.


27. CubeSat Summer Workshop - August 2007
    • Presentation: PolySat: Launch and Operations. This presentation, with Justin Foley during the CubeSat pre-conference workshop at the AIAA/USU Small Satellite Conference in Logan, UT, on August 12, 2007, discusses the recent Dnepr 2 cluster CubeSat launch. This presentation includes lessons learned and on-orbit data. It also gives a in-depth introduction of GENSO, and includes the function of the different servers and how they interact. The rest of the presentations from this workshop can be found here.


28. CubeSat Developers' Conference - April 2007
    • Presentation: PolySat: A University CubeSat Story. Presented with Parin Patel at the CubeSat Developers Workshop in Huntington Beach, CA, on April 20, 2007, this presentation discusses previous launches organized by Cal Poly, the launch failure, and GENSO. This presentation occurred three days after the successful Dnepr 2 launch from Baikonur Cosmodrome in Kazakhstan, so we were still doing preliminary checks on CP4. We hadn't heard from CP3 yet. The rest of the presentations from this conference can be found here.


29. AMSAT Symposium - October 2006
    • Paper: Amateur Radio and the CubeSat Community. This paper explores the mutually beneficial relationship between the Amateur Radio community and CubeSat developers. It also includes a discussion of bandwidth and handoff tests between the University of Tokyo, Lulea University of Technology, and Cal Poly, performed in April 2006. This paper was published in the conference proceedings.
    • Presentation: Amateur Radio and the CubeSat Community. Presentation of paper at the Radio Amateur Satellite Corporation Symposium in San Francisco on October 8, 2006.

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Updated 10 Feb 2022
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