I am part of the team that built the Bobcat-1 Cubesat from Ohio University. I’m making this thread to centralize the information I have on the launch and deployment dates/info for all the satellites onboard (including ours).
Launch Date: 2 October, 2020
Deployment Date (as of 2020-10-26): 5 November, 2020, starting at 9:05 UTC.
Satellites:
Bobcat-1
Owner: Ohio University Avionics Engineering Center
During passes over the OU Groundstation, we typically will initiate a FTP download of collected data. There is an example FTP download in the above zip, the content of the file download was the LSF Manifesto. The data we are downloading is essentially just messages from our NovAtel, and that format is described elsewhere online (see NovAtel’s website). During these high-baud-rate (100kBd) observations, the normal beacons will still be transmitted, but at the higher baud rate. There is also a mode implemented on the cubesat where we can request a burst of beacons, typically 10 beacons in a row with 400ms between bursts, but this is not always reliable and may not be used during actual operation.
Here is some information about the SATLLA-1 nano-satellite. SATLLA-1 nano-satellite is the first of a trio of nano-satellites aimed at demonstrating the ability of laser-based communications from space and testing the systems that enable it, which are being built by a team of students under the guidance of Prof. Boaz Ben Moshe at Ariel University.
The communication with SATLLA-1 is done via LoRa VHF and S-BAND. There are two types of beacons, short and long. Both beacons are byte array and we will share the beacons structure soon.
For more information, feel free to contact us at: kcg (at) g.ariel.ac.il (replace at. Avoiding spammers).
Unfortunately there will likely never be a LoRa flow-graph in SatNOGS due to the patent-encumbered nature of the LoRa physical layer.
The gr-lora project (which seems mostly abandoned?) does exist, but is reverse engineered, doesn’t perform well, doesn’t work with all parts of the LoRa protocol, and still has the patent issues surrounding it.
This means that while SatNOGS has a huge network of receiving stations around the world, none of them will be able to automatically receive telemetry from satellites transmitting LoRa. This is what you get for using a proprietary modulation technique unfortunately.
I should also point out that LoRa’s chirp spread-spectrum modulation is designed for use on the ISM bands, where there are usually many competing stations resulting in interference, which the spread-spectrum part of the modulation helps deal with. LoRa is well suited for those bands.
However, on the amateur satellite band, with frequency coordination and much less interference issues, all that spread-spectrum modulation does is use up far more bandwidth than is necessary (250 kHz on Norbi, really?!?!), resulting in potential interference to other satellites.
At some point there needs to be a discussion with the IARU about the use of proprietary PHY on the amateur radio bands…
On 435 MHz amateur radio band LoRA is already used for some APRS applications.
The above article mentions LoRA via VHF? The required bandwidth would not be compatible with existing IARU/ITU regulations on the 145 MHz amateur satellite band.
Not to to talk about legal issues, which may also be different in some countries and are still unclear…
Deployment is scheduled for November 5th, but could be as early as November 3rd. Get your stations ready! I’ll update again when we have a specific time. Updates are also posted here: https://twitter.com/Bobcat1_Cubesat
Deployment Timer info:
Bobcat-1 has a 65 minute timer after deployment before it will start to transmit.
SPOC has a 120 minute timer after deployment before it will start to transmit.
NEUTRON-1 has a 30 minuter timer after deployment before it will start to transmit.
LEMUR cubesats are not monitored by SatNOGS.
Still working with DESCENT on integration, no info yet.
SATLLA-1 is unfortunately using LoRa and cannot be properly decoded by SatNOGS, though we will observe it.
I have ISS State Vectors in J2K format from NanoRacks for this deployment.
Silo1 is Bobcat-1 and SPOC. Silo2 is NEUTRON-1. SILO6 is DESCENT/SATLLA-1. See attached:
NanoRacks also stated: “We’ve also calculated the estimated deployment velocity (dV) of SPOC & Bobcat-1 exiting the NRCSD 1.8 m/s.”
I believe NEUTRON-1 and DESCENT/SATLLA-1 should be very similar.
Thanks for the state vectors. For scheduling, however, it’s probably best to use the ISS TLE, as the largest uncertainty in the orbit will be the unknown drag. Hopefully there will be CSpOC TLEs soon after launch; if not we can use STRF to update the orbit.
For the teams, please make sure that the details of your satellite and its transmitters are right.
For station owners, these satellites will be available for scheduling tomorrow. As the satellites will be deployed from ISS we will follow ISS TLE for the first couple of days. This means that scheduled passes will overlap with ISS ones.
It’s perhaps a mistake and they wanted to talk about UHF LORA frequencies. I rem ember you that the picosat FOSSASAT have succesfully transmit on 436.7 MHz with LoRA but unfortunately for a too short time (https://fossa.systems/fossasat-1/). Anyway, an external RX circuit is required to receive but it is very affordable. It should be interesting to know the exact TX frequency.
To the station owners:
These passes are overlapped with ISS passes and will do for at least 2 weeks. There are and there will be some free slots left for ISS passes, that may be used for either ISS or scheduling one of the satellites above.
In case you want to change which satellite you want to observe on a future pass on your station, delete the pass/observation and schedule a new one. If you schedule one of the deployed satellites, don’t forget to use custom station horizon in advanced options with value 0, so we can track it better as we don’t have very accurate TLE.
Three comments on the scheduling:
Usually on new deployments we schedule the first 6h hours until we find better, than the preliminary, TLE. In this deployment, TLE are known as the satellites are deployed from ISS. In other words, ISS TLE are pretty accurate for the first days after the deployment.
The difference between the count of observations for each satellite has to do with the deployment time.
As SATLLA-1 uses an unsupported mode (for reasons that @vk5qi explains here) it got almost the half observations comparing to others for SSA purposes.
Its also worth pointing out that due to the very wide bandwidth of the mode compared to the ‘normal’ SatNOGS observation bandwidth (48 kHz), it will be difficult to discriminate SATLLA-1 transmissions from other local noise.
One comment for SATLLA-1 (cc’ing @kcglab), SatNOGS DB is able to accept frames from 3rd party (not in SatNOGS Network) stations through SiDS protocol and if a kaitai struct is provided (generated from decoding schema), we will be able to decode them and create a dashboard.
This is likely just due to setting our timeout too long, it’ll be an easy fix. We’ve changed the rest of the observations starting now till our next pass over OU begins (2020-11-06T04:42:02Z UTC) to be 9600 baud. Additionally, we are going to start increasing our baud rate more to find our highest stable baud rate. So, tonight from 2020-11-06T04:42:02Z to 2020-11-06T04:51:59Z, any observations during this time will observe Bobcat-1 using a 38400 baud transmitter. After this, we’ll go back to our normal 1200 baud beacons.
Our plan for tonight’s 04:42UTC pass is to test the 38400 baud rate and start a science data collection. Once that data collection is done, we’ll be increasing the baud rate as high as we can to download that dataset. Hopefully, we’ll get close to our 100,000 baud target!
