Visual observations

I am new here and have enjoyed browsing this site. I am a casual satellite observer and my main viewing equipment is binoculars. My question is can any meaningful contributions be provided by visually observing satellites? My understanding is that most observations are obtain by cameras and tracking tools. I would like to participate in providing observation results, but just curious if this is practical from visual stand point. Thanks


It may not help the community. All you could observe is a satellite. Or possibly a satellite. You won’t be able to identify it. There could be some kind of confirmation on the satellite that was supposed to pass during the time frame over your location. All you could confirm, will be some object passed. Since space is vast, and different object in different orbits may get illuminated by sunlight, you may observe a different satellite, further away from Earth, orbiting with a different speed.
In my opinion, it will not be worth the effort to look and track down using binoculars.

Fair enough. I should mentioned that I do use heavens - above, and satflare to track individual objects with good success. I guess my question was whether contributions using this method was practical, or are the majority of reports from observers with digital cameras

1 Like

Hi Greg,

Yes, visual observations with binoculars are certainly meaningful contributions. You’d require some way of timekeeping, probably using a stop watch or recording audio of your voice with an audible time tick. Visual observers typically try to mark the time when the satellite moves between two stars, or has a closest approach with a single star. You’d then need to use star charts or an online planetarium program to obtain the position.

Visual observers typically prepare their observing session by selecting which satellites to observe and to select suitable stars along the satellite track for position measurements.

For more information, have a look at


It is commendable for you to want to contribute but I must disagree with others and say that your binocular “observations” would (sadly) be of very limited use. In the early days they did use binoculars, etc but today you do need at least a camera. I strongly encourage people to take observations but this is an effort that requires some equipment.

Also, it is tough to get the time of observation within a few tenths of a second. You would need to know the position format to use in the IOD report. Etc.

I am working to document the procedures, etc to get valuable observations using very inexpensive equipment - I am using an older DSLR and can get very useable photos with a system that cost about $230 (US). Now I am wandering in the dark, trying various procedures to see which work best.

Here is an image that I got:

The good news is that, with inexpensive equipment, this is a quite possible. Let us know if you want more information about how to get usable observations.


As one who has always used binoculars for 18 years, I absolutely disagree with the naysayers. Imaging satellites adds nothing more, fundamentally, to the equation @CharlesHouston - Greg needs guidance in what he can do now, and that is legion.

  1. Magnitude of Starlink satellites is a very new and hot topic best approach by binoculars or naked eye.
  2. There are several satellites in LEO orbit lost to the public that need finding.
  3. Several satellites flare or tumble and this again is best seen visually. TruSat doesn’t currently have reporting on that activity but there are forums
  4. Recording these types of behavior is important for many reasons- health of satellite, space weather, etc

Please don’t let the naysayers tell you that you can’t ID it (you can) or that visual is pointless. Or at least if it is, I have wasted 18 years of my life.


Brad -

Don’t get me wrong, I am not saying that there is nothing of value from observing with binoculars. I am trying to directly answer Greg’s question; he asked about observations and I believe that observations (time, RA, Dec) are the data that TruSat needs and collects. I wish that even the 18th SCS included some magnitudes, etc etc for each satellite but they do not. In fact when I was an orbital analyst many years ago I tried to get them to include some information from radar returns but they were NOT interested.

If Greg spends time observing satellites and reports if they are tumbling - I don’t see where you would input that in TruSat. Where in TruSat (or anywhere?) can we go to see magnitudes of Starlink sats or anything? I do heartily agree that some archive of that would be wonderful.

The hard fact is that there are people out in the community collecting valuable information (does Mike use all of your observations yet??) that we don’t have a central repository for. A lot of people (like everyone at Space Track) is resting on their laurels (that is a great expression that we seldom get to use) instead of getting ready for the needs of tomorrow. Probably commercial groups like the ComSpOC and ExoAnalytic and LeoLabs has some of that information - but they are here to sell it.

I would hope that Greg and others would get started sending in usable observations and then go from there, that is my plan as well. But I hope that Greg does not spend a lot of time collecting notes about if satellites are tumbling, etc - and then not have a place to put that in TruSat.

Maybe one day TruSat will allow people to submit short videos of satellites, they would not be streaks like the ones I get but would be videos like people put on the FaceBook group, etc.

I hope you have not wasted your time because if you have - I have also wasted a lot of time.


Regarding my comments:

Starlink magnitudes: you can add magnitudes, optical behavior, and comments if you use TruSat entry form, e,g,:

See this thread for some of the ways the data is being used:

For flaring or flashing behavior calcs, Marco Langbroek has developed a great tool to provide PPAS format reports. These can be submitted to seesat mailing list (I highlly recommend you join), or directly to PPAS.

Mike McCants has a bunch of tools and other data here:

If you want to subscribe to seesat or want collection of ppas files and targets, let me know.
I don’t think the answer is to wait until everything is perfect and easy - part of the fun of satellite tracking is that is isn’t.

1 Like

Brad -

I have been a member of SeeSat for about 3 years.

Where on TruSat or SeeSat can you get any list of satellites and their magnitudes? You cannot that I know of; I would like to see that! When I submit observations I report optical behavior but don’t know if that is used.

Certainly some highly skilled people like Jonathan can use brightness measurements but would Greg be able to find them and contribute?

IMHO when people report that they are just trying to get started we should give them something that they can do and get feedback from, then take it step at a time. Let’s see if Greg has any comments or if he comes back and checks this discussion.


1 Like

Great discussion. @alternative3d and @swapnilsurdi Welcome to the community!

@alternative3d I recall someone around here making a fishing analogy, where visual-based observations are like line fishing, and camera-based observations have the potential to be like net fishing. Yes, a commercial net-fishing operation will result in larger volumes of fish, but a fish caught with a rod is certainly still valuable.

And mastering the rod is a great way to gain familiarity with fish behavior, water conditions, etc (along with an appreciation for the limits of this analogy :slight_smile: … you either catch a fish or you don’t, while the accuracy of a satellite observation isn’t as binary). With practice, as @hafsnt can attest to, it’s possible to make a sizable batch of visual observations in one session. :fish: :fish: :fish: :fish: :fish:

Visual observations are important in the case of TruSat because the project depends on observations from a wide range of contributors with broad geographic diversity. Making observations with the naked eye will be more accessible for many than observations with advanced camera setups. And visual observations submitted by someone from a region on Earth without other observers can be especially valuable data for calculating orbits.

Beyond observation methods, we’re hoping to grow this community, and any new contributor is more valuable to the cause than just the sum of their observations. So again, welcome, and thanks for your interest in the project!


Mike, Charles, Brad, and to every else, thanks for your help and suggestions. You really have provided a wealth of information. As mentioned earlier I am a casual observer, and my observing session usually consists of visibly identifying as many satellites with binoculars using the assistance of tracking apps. I have been doing this for many years but my interest in pursuing this passion at a more serious level, was a result of constantly reading sites like SatOrbs /satflare, which is how I discovered Trusat.

By all accounts I am a complete amateur, and it appears I will need to learn more before I am comfortable enough to contribute here.

Thanks again for the kind welcome, and if there are any other suggestions you can provide it will be most appreciated.



@alternative3d From what you’re describing, it sounds like you have more than enough experience to try contributing! But I know it does take time.

Out of curiosity, what specific knowledge/skills would you want to learn before feeling comfortable submitting observations?

I ask because we’re working to develop more instructional materials, and your perspective could help us in prioritizing tutorial topics.

1 Like

Hi Mike
I guess my hesitation in submitting reports is the accuracy of the observation. Specifically what would be the minimum requirements of report that would benefit the community from a strictly visual standpoint ? Someone commented on retrieving Starlink magnitudes, , or reports for tumbling satellites characteristics that I find fascinating. Perhaps instructional materials to assist in these areas?

Also, as an exercise I tried determining the time span of a starlink satellite between 2 stars using binoculars and a stopwatch the other evening. Although I was able retrieve a somewhat accurate measurement, this was more difficult than I anticipated given the margin of error that may occur. I am not sure how beneficial these reports would be.

I hope this helps and appreciate the interest, and support this group has provided.


1 Like

While Mike and the guys are putting together training materials, might I suggest a few resources and ideas:

You are ready to start submitting observations. Accuracy will come with practice, and the point of something like trusat is crowdsourcing. There will be a lot of people with a lot of different accuracies reporting, but the statistics will even it out in the end.

I can send you all of my reports about The starlink satellites, but it really would be easier for you just to retrieve them from see sat. You don’t have to subscribe to the mailing list to look at the archives. They are located at that way you can see all the other people’s reports also. My reports that includes starlink magnitudes usually have a title like BY SL and then the date, or some mention of starlink in the title of the email. Several other people have posted and usually have starlink in the title of the email. Jonathan McDowell may have a summary but you would have to contact him to find out. It’s such a new work-in-progress that data is still being gathered.

1 Like

Also regarding tumbling satellites, you can see same data in those archives. I usually start my email with BY P date or PPAS and other people post with some sort of indication like that too.

Another source is where the PPAS reports are called FPAS reports. Many of the PPAS reports appear here, and have been converted so that they are easier to understand. You can even get a visualization of many of the passes, and a description in words of what it was like.

So, @mike what would be the possibility of Trusat hosting the ppas data including my current updates? I can provide that data in text and csv form.

1 Like

@alternative3d This is very helpful! Thank you for your input.

Also, a tutorial on reporting magnitudes is a great idea.

@hafsnt is right in saying:

You are ready to start submitting observations. Accuracy will come with practice, and the point of something like trusat is crowdsourcing. There will be a lot of people with a lot of different accuracies reporting, but the statistics will even it out in the end.

The vision for TruSat includes many amateurs making observations of varying accuracy—including inaccurate submissions! The system will weigh observations by factors like the performance history of the observer. Observers who have consistently provided good results can advance the confidence of a satellite orbit more quickly than new or inconsistent observers. This is described in more detail here.

So a newcomer making inaccurate observations is still valuable to the system, as they’re going through the practice necessary to make more accurate observations later.

1 Like

And thanks @hafsnt. Regarding incorporating PPAS data into TruSat, it will be tough for us to get to this in the next couple months, unless we’re able to find more contributors to the code. But I’ll make sure this is represented in our list of feature requests at

1 Like