New tracker range test result

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Using a com spec system I saw the rocket at BlackRock before I got a signal from the unit. Was glad I had a Big Red Bee GPS unit also.
 
As others have said, during flight, eyes are up, so map is not important, but audio velocity and altitude would be nice... But at apogee and deployed, then pointer, bearing and map would be very beneficial. Here in Utah our two sites are flat, Bonneville salt flats, the other has dried creek beds and sage brush that rockets could get lost in, so having a map to see where it is would be very beneficial to planning route to rocket. Having to backtrack due to a steep inclined creek bed sucks.

Waiting to buy the GPS units so I can link it with the software and continue to use it. Hellfire is coming up, and would love to try it out on the salt flats! No cert flights planned, but want to put it in a variety of other rockets and see how it performs.

Ummmm, if using the Featherweight product at least for now you'll need to manually input the final lat/long into another device or app if you want a map. What is hoped for is one gets within the ground footprint of the tracker and gets a final position fix if
the rocket is not seen by the time they get to the last known position. I'm told that the ground footprint of any type of Rf device on the salt flats is less than it would be in say farmland.

Once a high flying rocket disappears, my attention is paid to the map and data trying to determine direction. As it comes into the expected main deployment altitude that's the time to be facing that direction to see if one can get a visual. Even if one gets just a momentary look that's a big help. One has visual assurance of where to proceed along with the map. With APRS one can open the radio squelch and even if the radio can no longer decode the position, hearing the "brrrrrrraaaapppp" in the static
is reassuring the tracker survived and when close enough can likely get a position fix. Remember, one can be so far away that a nominal deployment of the main can occur and they won't see the event or deployment. You'd be surprise how small rockets with trackers are totally unseen from short distances like 1/2 to 1 mile out even with a nice main deployment.

It would be easy with the Featherweight. Just keep your nose pointed in the direction the arrow tells you and look up and see if you can see the main event. Also one should consider blowing the main as high as they can tolerate as the propagation at altitude is better especially if getting close to the range limit of the device. Be cognizant of any ridges or solid obstructions the rocket could fly behind as that can lead to premature loss of signal. Those tips are applicable to any GPS tracker.

Consider shake down flights to see how any tracking system responds and keep the out of sight time to a minimum. If something's not right, you have the chance to get a visual on your incoming hardware and recover it conventionally.
I didn't do that and lost my first very pricey APRS tracker 11 years ago. Got the remains back and salvaged the hardware and the altimeter some time later. Kurt
 
Flew a Featherweight GPS today in a High school kids project. 54mm min dia J800 to 12K mach 1.8. Didn't loose lock. The App is very easy to use and phone and GPS units linked and accuquired satellites quickly. Landed a mile away. located the rocket in a wheat field..

Tony
 
Kurt,

Just FYI, I've been going to the playa since 2010. I've recovered rockets as far as 4.5 miles away with nothing more than a simple RDF tracker (an old rocket hunter system I bought shortly after I first started flying.) I have only ever used RDF recovery at BALLS (with multiple flights over 20,000') and have never lost a rocket there. And using regular FRS radios we get pretty much the same range as is typical. Plus Adrian has already tracked a rocket to over 100,000 feet at BALLS on the Playa using his system.


Tony

Good, I've heard from folks who've lost rockets out there because they lost their bearing and couldn't reacquire a signal. They won't consider flying without GPS tracking on aggressive projects now. I'm impressed if you were able to hold a bearing without any visual acquisition of events or of the descending rocket. Kurt
 
The only additional feature I would like is for the app to scream bloody murder if the rocket is coming in ballistic. Don't make my brain have to process the rapid decent, but let me set some threshold like 250 fps (after apogee of course) ahead of time (or have it hard set) to trigger the warning. My apologies if this has already been covered.

That, and availability...take my money!!!!!!!!

I take it that the Featherweight reports altitude?:wink::facepalm: Here's what you do, keep in mind the expected update rate of the tracker and watch the altitude descent rate. Keep in mind that perhaps not every position will be properly decoded
although Adrian reported that this device recovers ~90% or greater positions. There is going to be a range limit out there and I suspect it's going to be pretty far with this device. Basically, the closer the rocket is to the receive station, the lower the last position and altitude is going to be reported. The farther away, the last known position and altitude (holding the power output the same) will be higher up in the air.

Getting back to your descent problem, even with the "once every 5 second" update rate with APRS tracking I got a pretty good impression if the drogue was out as long as I received a string of reports once every 5 seconds.

You bring up another issue. One can get pretty "wired" monitoring tracking data. On one tracked ballistic flight I had that was nearby and about 2400 feet apogee, I only received one position before impact but that got me to the fincan. (Another product)
Never saw the rocket coming in and I knew it was out in front of me but didn't know where. Glanced at the map and I had an immediate idea. With the Featherweight there would be the additional step of inputting the lat/long into another mapping
device/app but that's no big deal as long as one is adept at transferring data. Keep in mind with a ballistic flight the tracker is going to die in the process so that last position "up in the air" is critical to get to the spot. On the other hand
the rocket is coming in hot so the hole is not too far away from that reported position in the air.

Tips: If you are getting nothing after apogee four things: 1. Tracker device failure. Antenna, or component breaks or loss of power.
2. The rocket flew so freaking far away it's out of range! (One is not likely to do that first time!) 3. Major deployment failure with a completely, parabolic ballistic flight. (Mine was with a "tracker test" rocket with motor eject failure and JLCR)
4. One doesn't do an adequate ground range test before flight. Stupidhead here found out after the fact that Dutch Boy rattle can metallic paints block 70cm/400Mhz Rf from getting out of the rocket very far. I know for a fact as
two projects one right have the other did not track at all at altitude at the same launch. One went ballisitic with no tracking and went lost for awhile the other I was lucky that an eagle-eyed participant caught it visually under a
full main and successfully returned to fly another day.

Sim your flights so you can have a bit of an innate clock when the launch button is pushed even use a stopwatch if you want to get particular to time the apogee based on the sim. Once the first few altitudes and positions come in just after apogee, you'll be able to eyeball the descent rate and breathe a partial sigh of relief until the expected main chute event. You'll be able to do it and don't sweat it. Yeah they'll be jitters, heck I get'em every time but the better you get at this the better you'll feel after a successful totally out of sight flight recovery.

Remember, if one hasn't flown a tracker like this before, there is no law that stipulates you have to send a rocket to "out of sight land" where winds aloft can hurl your rocket to any point of the compass on your first flight.
Do some modest flights where the rocket stands a very good chance of a visual descent so if something doesn't work, you at least get your stuff back to trouble shoot.

You'll have a blast tracking a descending rocket. I once looked up and saw everyone looking 180 degrees from where I knew the rocket was headed based on the drift trend on the map (the arrow on the Featherweight will tip you
also) I yelled out where to look and they were amazed. This was many years ago when only a few folks were doing APRS.

If enough people acquire the Featherweight tracker, I believe more that one receive station can "listen in" and a person can get the hang of it with "others" projects. That's how I tweaked my APRS skills if someone showed up with the
same APRS tracking hardware as I. Believe me, you folks are going to have more fun and enjoyment knowing that your chances of successful recovery are going to soar. Only worry will be if the rocket lands in an inaccessible place then. Kurt
 
I take it that the Featherweight reports altitude?:wink::facepalm: Here's what you do, keep in mind the expected update rate of the tracker and watch the altitude descent rate. Keep in mind that perhaps not every position will be properly decoded
although Adrian reported that this device recovers ~90% or greater positions. There is going to be a range limit out there and I suspect it's going to be pretty far with this device. Basically, the closer the rocket is to the receive station, the lower the last position and altitude is going to be reported. The farther away, the last known position and altitude (holding the power output the same) will be higher up in the air.

It's actually a lot more straightforward than that. The GPS chip outputs 3D velocity information (it's really accurate from what I have seen) and we're reporting the horizontal and vertical velocity real-time in the app.

Vertical velocity the main thing I watch real-time, because you can tell whether the apogee ejection and main deployments worked. Good idea about highlighting visually and probably audibly if the vertical velocity gets too fast.

With the Featherweight there would be the additional step of inputting the lat/long into another mapping device/app but that's no big deal as long as one is adept at transferring data. Keep in mind with a ballistic flight the tracker is going to die in the process so that last position "up in the air" is critical to get to the spot. On the other hand
the rocket is coming in hot so the hole is not too far away from that reported position in the air.

Most people now are just using the real-time pointing to walk up to their rocket. The Featherweight GPS stores the last valid data, so even if it comes in ballistic, you can still follow the directions right to the hole. (or crater, in the case of a 137,000 foot flight at BALLS with a failed deployment)
 
It's actually a lot more straightforward than that. The GPS chip outputs 3D velocity information (it's really accurate from what I have seen) and we're reporting the horizontal and vertical velocity real-time in the app.

Vertical velocity the main thing I watch real-time, because you can tell whether the apogee ejection and main deployments worked. Good idea about highlighting visually and probably audibly if the vertical velocity gets too fast.



Most people now are just using the real-time pointing to walk up to their rocket. The Featherweight GPS stores the last valid data, so even if it comes in ballistic, you can still follow the directions right to the hole. (or crater, in the case of a 137,000 foot flight at BALLS with a failed deployment)

That is fantastic. I can only see horizontal velocity and a scrolling altitude, not vertical velocity on the apps I'm confined to use currently. Do tell, is the vertical velocity with the GPS constrained by treaty also or is that horizontal velocity only?
For the uninitiated there are limits on consumer GPS devices so one wouldn't be able to use COTS (Consumer Of The Shelf) devices to do something devious. 1000knots and 60k I believe were the limits. Some GPS chipsets locked out on both (1000 knots OR 60k) so they were unsuitable for H.A.B. (High Altitude Ballooning) tracking. There are a large number of chipsets that lockout at 1000 knots but if used on a balloon can go to 156,000 feet last I heard. I used to track some balloons cruising at 175 mph in the
jet stream in the past at the mid upper altitudes. When they get to 70 -100k they generally, lazily float around until envelope rupture. Kurt
 
That is fantastic. I can only see horizontal velocity and a scrolling altitude, not vertical velocity on the apps I'm confined to use currently. Do tell, is the vertical velocity with the GPS constrained by treaty also or is that horizontal velocity only?

We have gotten good live GPS data from rockets flying vertically well over the u-Blox spec max velocity of 100 m/sec. The spec max altitude is 50 Km (~164,000 feet), and we don't know yet what it does in that situation.
 
One word. A N D R O I D!

Take my money, please. :)

Very excited to hear about the beta testing and progress. As soon as they are available for Android, I'll be ordering at least two of them.
 
Semi off topic question here:
With the high reliability and accuracy of this GPS tracker, has anyone at Featherweight considered developing a companion device that would be something along the lines of a Tender Descender, or JLCR without the brains? This companion could be linked to the tracker for triggering either by a tether cable or wirelessly, say using BT? (I would vote BT)

Such a combo would be a real boon to those that for whatever reason, will not or cannot use Dual Deploy.
 
Ok, so Adrian has been prepping units on his end and I just finished this batch of 28 (14 ground stations and 14 trackers) that I'll send to him today....

Not long until Adrian opens the store...!! :smile:

Screen Shot 2018-05-31 at 7.13.15 AM.jpg
 
A quick update: We were about to open up ordering for everyone, but a customer who bought a unit at LDRS uncovered a vulnerability with the current firmware: if you have a bad power connection that causes intermittent power, you can get a corruption of the Bluetooth module flash memory, which prevents connection to your phone and can only be fixed by reprogramming the unit with a special hardware programming tool. Kevin is working on an improvement that looks promising for preventing this problem for new units, and we hope to open orders soon.

Update 6/5/2018: We confirmed that the problem is was in the bootloader code that came from the chip manufacturer, and Kevin came up with a fix that avoids the problem. As soon as we prepare and test enough units with the new firmware to get a good start on the orders, we'll open up ordering.
 
Looking forward to it.

Are you able to post any specs on the transmission frequency/power so I can look into the Australian regulations?

I will hold a HAM license in July which avoids most of the limitations.
 
Looking forward to it.

Are you able to post any specs on the transmission frequency/power so I can look into the Australian regulations?

I will hold a HAM license in July which avoids most of the limitations.

It's a non-HAM band, 915 MHz.
 
In Australia there might be some different frequency requirements, even though it's on the non licensed band in the USA.Twobit might
be able to comment. Kurt

I addressed this on page 3 of the thread and here's Adrian's response below.

Yes, the frequency for the dedicated comm to/from your own ground station will be user-selectable over a wide range. I have been planning to have some special-purpose fixed-frequency public channels as well, and I understand that for you guys down under you would need those to be in 915-928 MHz range as well.
 
The LIPD class license for the ISM band in Australia for the "900MHz" band starts at 918MHZ, not 915MHz like a lot of other places in the world. Australian units are required to not transmit below 918MHz, so as to not interfere with Telco services.

As a rule I make sure I transmit on 919MHz or higher if I am using that band, to ensure a sufficient buffer so I don't end up with any significant out-of-band emissions.

https://www.acma.gov.au/Industry/Sp...ass-licences/lipd-class-licence-spectrum-acma
 
The LIPD class license for the ISM band in Australia for the "900MHz" band starts at 918MHZ, not 915MHz like a lot of other places in the world. Australian units are required to not transmit below 918MHz, so as to not interfere with Telco services.

As a rule I make sure I transmit on 919MHz or higher if I am using that band, to ensure a sufficient buffer so I don't end up with any significant out-of-band emissions.

https://www.acma.gov.au/Industry/Sp...ass-licences/lipd-class-licence-spectrum-acma

I could probably create a virtual 'box' around Australia so the frequencies outside the allowed range are not available.
 
I could probably create a virtual 'box' around Australia so the frequencies outside the allowed range are not available.

If you're looking for names you could call it Amazon! :lol:
 
Sorry for the vagueness of the initial query. I did see the frequency details on page three and repeated above here.

It was more querying along the power and method/technology as the details I read for Australia is 915 to 928 MHz (OverTheTop mentions 918 as the start) for Frequency hopping transmitters and digital modulation transmitters with a maximum of 1 watt for frequency hopping transmitters and must use a minimum of 20 hopping frequencies.

https://www.acma.gov.au/Industry/Sp.../shortrange-spreadspectrum-devices-fact-sheet


This range is not within the HAM licence so holding it or not has no benefit.
 
Thanks for prompting me to have another look at that twobit :). I just checked the latest class licence and it does in fact say 915MHz as the low end (for both FHSS and digital modulation schemes). Definitely not what I remember having seen a couple of years back. Check items 54 and 58 in Schedule 1 of the CL document here: https://www.legislation.gov.au/Details/F2016C00432

So it looks like 915MHz is good for Oz now!

I have noticed in the past some changes in this document. The LIPD seems to be evolving in a fairly contemporary fashion. I guess the lessons are that "the only thing that is constant is change", and "check the current documents".

Note that the Radio Frequency Identification transmitters still have lower limits of 918MHz (1W max) and 920MHz (4W max) under this class license, but these do not apply to us.
 
Is there any chance that I can tell my wife to order one of these systems for me for Father's day?
 
Adrian, I just bought the Full System and really looking forward to it. For those who opt not to get the two tracker setup, is it possible to add that second tracker at a later date? Or, are the ground station and flying tracker locked to each other and no alterations possible, such as in a CATO or similar?
 
Back
Top