SNAPS Ground Station Winter Quarter 2013 Final Report

Transcription

1 SNAPS Ground Station Winter Quarter 2013 Final Report SNAPS Ground Station Team: Rahul Gupta-Iwasaki-KK6ALJ Steven Shepard -KK6ANA Manu Sharma Introduction For this quarter, we set the following goals: 1) Work with Timothy Stranex (Carpcomm) to get IQ data decoded accurately and consistently. (Done successfully once, but should be tested again - Note: we must include 25kHz frequency difference between transmitter & FCD/SDR ) 2) Characterize Link budget/ get dimensions of Durand Roof Yagi 3) Adapt LMRSAT s packetizing code developed on the MSP430 for our packetizing scheme. 4) Port adapted LMRSAT packetizing code over to the STM32 microcontroller. 5) Develop a cloud-based server in Azure to automatically poll Carpcomm s database 6) Gather TLEs upon satellite launch for satellite tracking with SatPC32 (Now Ham Radio Deluxe) 7) Obtain new USB to Serial converters for newer MS OS. 8) Provide final packet decoding scheme to Carpcomm. (Optional) 9) *Obtain Bias T and interconnectors to diminish Noise Figure in Ground Station downlink * This task was added mid quarter Select Ground Station Network Ground Station Networks A ground station network is a collection of ground station nodes across the world that each downlink data from any of the satellites affiliated with the network whenever they are overhead. They are ideal to capture more data sent from the satellite throughout an orbit and they provide convenience in collecting and analyzing the integrity of packets. The ground station networks that we initially considered were: Genso, University of Michigan, and CarpComm. CARPCOMM STATION OVERVIEW AA236B_ _GS_FinalReport.docx p.1/22

2 For this SNAPS cycle we are only connected to the CarpComm Ground Station Network. The University of Michigan network failed to respond with the information as to how/where we would retrieve our data and whether or not we could access the raw binary data in the case of an alteration of our data packet scheme. Genso is no longer an active ground station network. The CarpComm network currently has at least 3 to 4 active ground station nodes working in locations all over the world. The node set up is easy and inexpensive which allows the potential for a few more ground stations to be added in more locations ideal for SNAPS s orbit in the near future. The CarpComm network does SDR signal processing/ I/Q data encoding on their end, and has implemented 1200 baud AFSK, 9600 baud FSK, and Morse code. It is necessary to inform CarpComm which of these demodulation processes you want to be used, and we have specified our desire to us the 9600 baud FSK. Once they have the raw bytes from a packet CarpComm also offers to interpret the data in to readable telemetry. The raw packets and the decoded value instances are stored in a database. The CarpComm network is not restrictive in decoding packet schemes. We can thus obtain the raw packets composed of the raw bytes (usually represented in ASCII characters) for us to interpret on our end. For the purposes of this mission we have requested to receive just the raw packets because our decoding scheme is bound to vary during our development stages. The data is collected and organized under the respective satellite missions by the CarpComm network for the teams to access. For every byte that we want to access, we must provide a byte of information from another satellite on the network; otherwise we must make a commercial arrangement with CarpComm. Figures 1 and 2 show the data flow using the Setup1 and Setup 2. Integrate Stanford Ground Station to Ground Station Network a.) Components Hardware: Yagi Antenna (on roof)* Yaesu G5400 B Rotor Controller Yaesu GS-232 Computer Controller ICOM 910 Radio TNC (Kantronics 9612) SSDL_Juno Windows (XP) Machine SSDL-Carpcomm Ubuntu Machine (Virtual) FunCube Dongle Pro+ and Bias-T Software: Ham Radio Deluxe (HRD) (Satellite Tracker, Radio Interface, Time Sync; Windows) VMWare Player (Windows) CarpSD (Carpcomm; Ubuntu) X-CTU HyperTerminal AA236B_ _GS_FinalReport.docx p.2/22

3 AA236B_ _GS_FinalReport.docx p.3/22

4 Figures top- bottom: (Left Column) ICOM 910-H Radio Transceiver; Rotor Controller; Yagi Antenna on Durand roof (Right Column) FunCube SDR Dongle; Kantronics 9812 TNC; Ham Radio Deluxe satellite Tracker Running on Ground Station computer. *Antenna Specs: There are two antennas attached to a single boom for use via the ground-station room In the 2 nd floor of Durand. The 400MHz range antenna is a 38 parasitic element, 14ft, Yagi antenna with 2 perpendicular driven elements. The 140MHz range antenna has 20 parasitic elements, is 14ft in length and has 2 perpendicular driven elements. All elements on both antennas are alternately arranged in either the horizontal or vertical. The electromagnetic properties of the 400MHz range antenna can be found in the link budgets provided below. b.) Operations The SNAPS Ground System handles telemetry and commands for the SNAPS satellite. For this phase of the SNAPS mission, we are primarily receiving packets containing telemetry and image data. The packets of data are stored on a database in Carpcomm s server, our Ground Station Network. The data can then be downloaded from the Carpcomm website and stored in our local log file. There are currently two different ways to operate the ground station: 1.) with traditional equipment 2.) with the newly developed software defined radio. The station is operated by way of 1 or 2. It is not possible to do both. Setup 1 With the traditional equipment the packets of data move as follows: from the transmitter- to our Durand antenna- to the ICOM 910 transceiver- to the TNC - and finally to our computer where the data is routed to Carpcomm's network and our own local log file. Automatic Network Upload CarpComm has a server side program that estimates when a satellite will be overhead which node and automatically turns on that node s TNC and grabs the incoming data through CarpSD. Manual Network Upload A ground station operator can manually route data to CarpComm s network by 1. Log on to CarpComm Website 2. Go to Ground Station Console 3. Set the frequency your receiver is set to 4. Select SNAPS from the TNC dropdown menu AA236B_ _GS_FinalReport.docx p.4/22

5 5. Select Start. Problems The Kantronics 9612 TNC worked fine passing data all the way through to CarpComm s network when the baud rate (the symbols per second specification necessary for accurate demodulation of audio signals) was at 1200 baud. When information was sent at 9600 baud the signal passed through the ICOM 910 but failed to post on to CarpComm s network. We have thus concluded that there is a problem with the TNC s processing at 9600 baud. This is still under investigation. Setup 2 With the software defined radio the packets of data move as follows: from the transmitter - to our Durand antenna- to the FunCube dongle- to our computer where data is either visualized/ heard on SDR #v on the Windows OS, or the data is routed directly to Carpcomm s Network while running CarpSD on the Linux. Data is always automatically routed to Carpcomm through CarpSD. Data In Setup 1 AA236B_ _GS_FinalReport.docx p.5/22

6 Data In Setup 2 AA236B_ _GS_FinalReport.docx p.6/22

7 Navigating Carpcomm website The Carpcomm website is very simple. There is a Ground Station Console page where the user can manually start listening with the TNC. This is ideal for testing data transmission from a geostationary source, or beacon source whose orbit is not tracked by Carpcomm. When using the SDR it is possible to see the output Fourier transform in the waterfall window as the audio signals go to CarpComm s server. SNAPSHOT The Contacts page Carpcomm posts all of the data received from your station. This is where we retrieve/ download all of our data. AA236B_ _GS_FinalReport.docx p.7/22

8 SNAPSHOT d.) Testing Equipment: SNAPS He Radio Beacon Development Station Power supply Helium radio (w/ debugger port) Kenwood FM dual bander handheld radio with TNC, X-CTU CarpSD/Carpcomm ground station software, Carpcomm Website Rowly Crossworks Hyper Terminal. Our preliminary testing was done on our lab station in Durand 012. We built our data packets into the reconstituted LMRST code and then observed that the same packet structure was carried through the X-CTU terminal (which shows received data from the Kenwood handheld radio) and through CarpSD and then into the station contacts page at Carpcomm.com (where all received data is posted). We will soon be testing in the 2 nd floor Durand Ground Station room with the Software Defined Radio along with the Helium radio as a transmitter to send our new packets via the reconstituted LMRST code. There are few things to note regarding testing. Our final code packetizing code will consist of modified modules of the LMRST code with all unnecessary functionality stripped out (i.e. functionality unrelated to packetization and Tx/Rx for the Helium radio. In order to test on AA236B_ _GS_FinalReport.docx p.8/22

9 the lab station in Durand 012 we had to reinstall Python 2.7 onto our lab station as well as X- CTU and CarpSD. Installing CarpSD was troublesome as we eventually had to install it on the admin account on our lab station due to read/write permission settings on the other account. CarpSD expects the TNC to be is in KISS mode and the packets transmitted by the original version of the LMRST code to adhere to the Ax.25 protocol. This took some time to figure out and eventually was resolved after looking at the open source repository of CarpSD available through CarpComm and deep investigation into the manual of the Kenwood handheld radio. Description of Downlink Parameters Submission for IARU 5c SSDL Ground Station, Durand, Stanford Campus Contact- Andrew Kalman, 6b Attached 6c Yes. Transmitted using AX.25 8a Typical Earth Station used to transmit operates at GHz, using: directional Yagi Antenna, TNC (e.g. Kantronics 9612 TNC) in conjunction with radio (e.g. ICOM-910), ground station software and satellite tracking software 8b Attached 9a Directional yagi antenna, software defined radio, satellite tracking software, ground station software for collecting signal and later interpreting it (e.g. CarpSD) 9b Attached DownLink/Uplink Budget (Typical Amateur Radio Ground Station, using the System Link Budgets given below in the following figures provided by COMMS as well as information provided by previous mission: OPAL, MAST and LMRST) These are the link budgets obtained from the ground station Category Dimensions Value Orbit Altitude km 300 Spacecraft Elevation Angle Degrees 90 Frequency GHz Transmitter Power (SpaceCraft) Watts 4.00 Transmitter Power (SpaceCraft) dbw 6.0 Transmitter Line Loss (SpaceCraft) dbw -1.0 Transmit Antenna Gain (SpaceCraft) dbi 3.45 EIRP dbw 6.3 Category Dimensions Value Propogation Path Length Maximum km 1000 Space Loss db Polarization Loss (SpaceCraft) db -0.2 Receive Antenna Diameter (Groundstation) m NA, yagi antenna, 14ft boom length, 38 elements AA236B_ _GS_FinalReport.docx p.9/22

10 Receive Antenna Efficiency dbi (Groundstation) Peak Receive Antenna gain dbi (Groundstation) Rx Antenna Line Loss db (Groundstation) Rx Antenna Beam Width Deg 30 (Groundstation) Rx Antenna Pointing Error Deg -+3 (Groundstation) Rx Antenna Pointing Error Loss db 1.3 (Groundstation) Rx Antenna Gain w/pointing Error db (Groundstation) System Noise Temperature K 370 Data Rate bps 9600 Eb/No db 29.9 Bit Error Rate 1.00E-06 Required Eb/No db-hz 18.0 Implementation Loss db -2 Margin db 11.9 Provided by COMMS Team AA236B_ _GS_FinalReport.docx p.10/22

11 Submission for FCC/ITU C10b1 Associated Earth SSDL Ground Station Station Name C10b2 Type of Station Specific O AA236B_ _GS_FinalReport.docx p.11/22

12 C10c1 Geo Coordinates Following are for Ames Longitude W 121 Degrees O Latitude N 37 Degrees O C10c2 Country USA O C10d1 Class of (Earth) TA (Earth Station in the Amsat Service) Station C10d2 Nature of Service CV Station Open exclusively to the correspondence of a private agency Define Packet Structure for Data and Telemetry Radio Application Packet: Radio packets are transmitted over wireless links. This will be wrapped by AX.25. Radio packets contain Concise or Long Application Packets. Maximum packet size is 256 with the Helium Radio. Header and Checksum are 8 Bytes. Therefore Data must be 248 bytes. Field Name Size (bytes) Notes Sync 2 Hexidecimal: AB CD Decimal: Marks beginning of packet Length 1 Number of bytes in the entire radio packet (including sync and checksums). Currently, this must be less than 256 Primary ID 2 Provides address space for satellites or organizations. Flag 1 Additional packet characterization. To recognize the presence of a Concise or Long Packet AA236B_ _GS_FinalReport.docx p.12/22

13 Data 248 Number of data bytes. Checksum 2 FLETCHER-16 Concise Application Packet: This packet beacons very frequently - approximately every 20 sec. Data packets contain telemetry and parts of image Field Name Size (bytes) Notes CAP Size 1 Number of bytes in the entire DAP packet Timestamp 4 Four bytes of UTC, time t. This will last us till Data bytes Telem, 20 bytes Image Checksum 2 FLETCHER-16 Long Application Packet: This packet beacons in a ground station-synchronous pattern the cycle is resynchronized by a message from the Stanford GS Field Name Size (bytes) Notes TAP Size 1 Number of bytes in the entire TAP packet. Timestamp 4 Four bytes of UTC, time_t. This will last us till Data 241 Only Image Checksum 2 FLETCHER-16 Adaptation of LMRST radio code for SNAPS Currently LMRST code has is packetizing in our RAP format. Small amount of work needs to be done to change the telemetry format to ours and add a DAP creation module. AA236B_ _GS_FinalReport.docx p.13/22

14 Future Work 1. During test later in the quarter we noticed inconsistencies in retrieving data transmitted through Carpcomm network. This must be addressed as soon as possible. 2. Porting the adapted LMRSAT packetizing code over to the ARM7 STM32 3. Developing a cloud-based server in Azure to automatically poll Carpcomm s database 4. Gather TLEs upon satellite launch gather 5. Give final packet decoding scheme to Carpcomm. 1. Following Timothy Stanex s instructions for sending data 25kHz above receiving frequency and allowing for 6 seconds of warm-up for Carpcomm s demodulation when manually transmitting data on we still ran into a proble m of only about 2/5 packets successfully displaying ASCII characters on the Carpcomm server 2. The adapted LMRSAT code has been sent to the CDH team and is currently under investigation as to how this can be accomplished. 3. The final step required before launch is to implement and deploy a server for automatic polling of Carpcomm s database. The server will poll for the latest raw (not yet decoded) data transmitted from the satellite and then decode it. This entails decoding basic telemetry data as well as image data and then posting it to any website of interest. It has been decided that instead of Carpcomm having to constantly adjust its decoding scheme during SNAPS development (nominally each adjustment would take 1-2 days), we have Carpcomm only store raw data. In so doing we would be able to quickly make changes to our decoding scheme and still see data decoded just as quickly after having passed through Carpcomm. The future cloud-based server will be composed in Azure and will most likely require some kind of fee based on data usage. Because of these fees, it will be important to ascertain whether NSF or other granted funding will be allowed for use with Azure (there have been complications in the past with using funding for cloud computing). 4. Upon SNAPS launching we must gather the TLEs for it from NORAD. These are used in the satellite tracking software (HRD) residing on windows on the SSDL_Juno machine in the ground-station room on the second floor of Durand. While the operation of this software is not paramount to the operation of the groundstation as Carpcomm will automatically notify CarpSD residing on Ubuntu/Windows on the SSDL_Juno machine that it a satellite is overhead and that it should start recording, it would be useful to have a visual of what satellites are present in the sky and where they are at any given time. AA236B_ _GS_FinalReport.docx p.14/22

15 5. Once SNAPS has been launched it would be appropriate to give Carpcomm our latest packet decoding scheme. This is per Timothy Stranex s request as he feels readily decoded and open data from Carpcomm s users displayed on Carpcomm will help build the amateur radio community as well as build support for Carpcomm. Ground Station Manual Appendix A Licensing To legally operate a ground station according to the FCC, a radio operator must have a HAM license. These are fairly easy to obtain. All it requires is passing a 35 multiple-choice test on basic electronics, safety precautions, and radio protocols. You can study online and learn more from the National Association for Amateur Radio website: There are different levels of licensing, but at least a Technician license is recommended for communicating at 30MHz +. You can also find a testing location near you online. TRADITIONAL GROUND STATION- SANS SDR Instruments: Antenna (on roof) Yaesu G5400 B Rotor Controller Yaesu GS-232 Computer Controller Radio (icom910h) TNC (Kantronics 9612) Software: Ham Radio Deluxe CarpComm Operation AA236B_ _GS_FinalReport.docx p.15/22

16 Operating the ground station implies the one of the following actions: Receiving information over certain frequencies; transmitting information at certain frequencies; tracking orbits. ICOM 910 specifics Duplex operation Sat mode: Main Band Receives (Rx) Sub Band Transmits (Tx) Non-Sat mode: Main Band Transmits and Receives (Rx/Tx) Receiving Data (receiving/ RX) Information is first in the form of RF signals in the air, which are captured by our Yagi antenna on the Durand roof. From the roof antenna the signal moves into the ICOM 910 radio or the SDR, From the ICOM 910 radio to the Kantronics TNC. The Kantronics TNC demodulates the audio signals into digital data in the AX.25 protocol. From the Kantronics TNC the data moves to the computer. The hex representation of the data is automatically documented on a log txt file saved to the desktop. KISS Mode (Keep It Simple Stupid)- The KISS mode for a TNC simply keeps the TNC module on a listening mode for when no operators are present. Transmitting Data (transmitting/tx) Initially, we did not plan to transmit commands to SNAPS due to ITAR regulations. However, we are currently working with the Stanford Amateur Radio club to use license SNAPS under one of their Stanford-unaffiliated call signs. This will allow us to circumvent ITAR and command SNAPS from the ground. Transmitting data is similar the process for receiving data, only reversed. For outgoing data, data moves from some digital platform usually a controller to a radio that converts the digital data in to RF signal. The signal would then propagate in the air until a receiver catches it. Tracking Orbits The ground station can track orbits with Ham Radio Deluxe. The program has a visualization of orbits of different satellites. The satellites currently tracked are all the ones on the CarpComm network, but any satellite can be tracked. The program uses TLEs originally from Norad and makes a visualization of their predicted orbital paths. It is useful to use the program to test pushing data from the TNC or SDR to the Ground Station Network. You can manually start listening at the frequency the satellite that the Ham Radio Deluxe shows to be in the overhead is reported to be communicating at and see if information successfully makes its way through the Ground Station System. AA236B_ _GS_FinalReport.docx p.16/22

17 GROUND STATION WITH SDR Instruments: FunCube Dongle Pro+ with Bias-T Software: SDR #v Ham Radio Deluxe (HRD) CarpSD Ubuntu on VMware Player Virtual Machine Operation The FunCube Dongle is a software defined radio (SDR) that connects to an antenna via standard SMA female antenna port on one side and it connects to a computer on the other side via USB 1.x type A male connection. Its frequency range is guaranteed from 150kHz-240 MHz and 420MHz-1.9 GHz. The FunCube Dongle is compatible with Linux, OSX, or Windows, but the SDR is only supported with the CarpComm Network with Linux at the moment, and is therefore the OS that will run on a Virtual Machine in the Ground Station for the SNAPS cycle. We have been informed from CarpComm they are developing a Windows platform with the SDR. Setting Frequency for SDR The frequency can be set many different ways. When the SDR is connected to the Windows OS, the frequency can be set in the SDR # v program. When the SDR is connected to the Linux OS, the frequency can be set on Carpcomm s website by manually typing in the frequency on the Station Console page under Stanford SSDL. CarpComm will set the frequency of the SDR from their server when they need to listen to a satellite that is overhead our Stanford Ground Station. Baud rate A big upside for the SDR is that it does not need to change anything to received different baud rates. It has no restrictions on modulation schemes. The baud rate is only important when encoding I/Q data, which involves signal processing, which the SDR does not do. Currently we leave this encoding step to CarpComm. We might in the future consider obtaining our own software to demodulate the I/Q data in to raw packets. AA236B_ _GS_FinalReport.docx p.17/22

18 Appendix B Ground Station Software Software Used: Windows XP Version: Service pack 3 Cost: $$ Source: (no longer officially available) US/windows/service-packs-download#sptabs=xp Installation: Insert XP disk into computer, reboot and choose boot from CD, follow installation instructions Usage: This is the current operating system on SSDL-Juno. HRD - Ham Radio Deluxe (Windows)* version: SatPC32 V.12.8b (2011) cost:free Source: Installation: Follow instructions at Usage: A satellite tracking program for windows. The software is designed for showing satellite positions on screen, taking the azimuth and elevation positions and controlling the motors on the dish. This software uses the orbital pattern of satellite and the time of day, then calculates the position of the satellite in relation to the observer. SatPC32 also allows selection of different tyes of commercially available rotors either a serial port or parallel port CarpSD (Linux) AA236B_ _GS_FinalReport.docx p.18/22

19 Version: Commit b9438a017c Cost: Free and Open Source Source: Installation:Follow instructions at Usage: Start using command sudo /etc/init.d/carpsd start. No control can be had from within the program itself - rather, use the Carpcomm website to control the ground station software. Further instructions at CarpSD (Windows) Version: Commit b9438a017c Cost: Free and Open Source Source: Installation: Download CarpSD from Carpcomm github repository, install Python 2.7 on admin account (required for proper read/write permissions) on lab station in Durand 012, install CarpSD Usage: Started by opening the start-gss.bat file. Can use init.config file to change initialization settings, though it shouldn t be necessary. Again, no control can be had from within the program itself - rather, use the Carpcomm website to control the ground station software. SDR# Version: Cost: Free Source: Installation: Download installer, run, and follow instructions Usage: SDR# VMware Player Version: builld Cost: Free and Open Source Source: Installation: Download installer, run, and follow instructions Usage: Program to create, manage, and run virtual machines. We installed VMware Player on SSDL-Juno to host and run an Ubuntu VM within which we ran CarpSD interfaced with the FunCube Dongle Pro+. Ubuntu Version: generic-pae #52-Ubuntu Cost: Free AA236B_ _GS_FinalReport.docx p.19/22

20 Source: Installation: Download the image, create a new virtual machine using VMware Player, choose the downloaded image as the boot disk, boot the virtual machine, use the installer presented within the virtual machine to install the Ubuntu onto the virtual machine. Usage: Ubuntu is one of the most popular versions of Linux. The FunCube Dongle Pro+ is only supported in the linux version of CarpSD, so we use Ubuntu as our operating system in our virtual machine on SSDL-Juno. X-CTU Version: Cost: Free Source: Installation: Download installer, run, and follow instructions Usage: A terminal emulator we use to interface with the TNCs of the Kenwood TH- D7 handheld radio and the Kantronics 9612 TNC. Displays both hex and ascii representations of data and can be used to compile hex packets to send to the TNC (used to exit KISS and conversation mode). HyperTerminal Version: 5.1 Cost: Free Source: Installation: Download installer, run, and follow instructions Usage: Like X-CTU, HyperTerminal is a terminal emulator we use to interface with the TNCs of the Kenwood TH-D7 handheld radio and the Kantronics 9612 TNC. Displays only the ascii representations of data and cannot compile hex packets. More useful as a dumb terminal for output. * This software was installed during the Winter 2013 quarter and replaced the SatPC32 program. Appendix C Quick Start-Up Guide - Quick guide for starting up CarpSD on SSDL_juno and operating CarpSD in conjunction with Carpcomm.com to record and view data Step 1) make sure SSDL_juno machine is on Step 2) start up VMPlayer and open up the groundstation VM Step 3) log into VM AA236B_ _GS_FinalReport.docx p.20/22

21 Step 4) go to Player->removable devices, then make sure the FunCube Dongle Pro+ is connected Step 5) in the terminal enter: sudo /etc/init.d/carpsd start - This will start CarpSD Step 6) then enter: lsusb to make sure that the FunCube is connected through the USB port Step 7) log into Carpcomm website Step 8) if wanting to use the station manually: go to console control page and make sure that automatic is unchecked for the TNC control - If wanting to use the station automatically controlled by Carpcomm then leave automatic checked and proceed directly to step 11 Step 9) click start tnc Step 10) click start waterfall Step 11) go to contacts page on Carpcomm website to view received data Optional) to peek into log file, in VM at the terminal type: tail /var/log/carpsd/carpsd.latest.stderr Optional) to stop CarpSD on the VM type in the terminal: sudo /etc/init.d/carpsd/ stop Appendix D AA236B_ _GS_FinalReport.docx p.21/22

22 TNC Kantronics 9612 Schematic Support Contact the SSDL for any questions, suggestions, or issues. GS Team Contacts: (ex) John Cast Rahul Gupta-Iwasaki Steven Shepard Manu Sharma AA236B_ _GS_FinalReport.docx p.22/22