Best GPS tracking system?

Discussion in 'Rocketry Electronics and Software' started by rocketgeek101, Sep 8, 2019.

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  1. Oct 19, 2019 #61

    ksaves2

    ksaves2

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    Thanks Steve, Yeah the Multitronix system is impressive for sure. I like the one video posted of a very high flying project that had the camera affixed to record the screen of the Kate system receiver for the entire flight. Vern Knowles really did his homework on this. I recall that the system had a very high recovery rate of data as opposed to the more economically priced systems I’ve been used to.
    Even then, there sometimes would be a few seconds to where there wasn’t a data update and it was later in the flight. Not early where GPS lock is lost in the initial high speed flight. Still, it’s about the best as long as one has the means and the footprint for it.

    Incidentally, when I was dabbling with Linux text to speech using Festival years ago, I swear there was an open source speech module out there for Kate along with a bunch of other voices male and female.
    It would follow that Vern would likely use an Open Source resource to avoid any legal issues.
    Kurt Savegnago
     
  2. Oct 19, 2019 #62

    ksaves2

    ksaves2

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    Ummmm, yes respectfully, keyboarding is not live mapping. Live mapping is where the incoming positions are directly sent to mapping software for instant display while the rocket is in flight. The advantage here is one can see directly the drift/position trend while the rocket is in flight and hence one has the time to point their eyeballs to roughly the the direction where the expected main chute event is supposed to occur. Many times one never sees the rocket or chute deployment if it’s far enough away. Small rockets are hard to see even with the chute out. It’s a great feeling even if one can’t see the rocket under chute to see that descent rate slow after the expectant main deployment. I experienced it first with the Beeline GPS and the Garmin 60Cs and Kenwood D72A with the D72 screen set to display get GPS altitude. I didn’t need to see lat/lon as my rocket was being shown live on the map directly. One knows when the expected main deployment is coming up. The Eggfinder TRS goes one step further as it gives an indication on the LCD receiver display that the current has been sent to the ematch!

    Also with live display of positions on a map, as the rocket is getting lower under the main chute, one can see the drift trend very clearly. If the rocket just goes out of range as it’s lower under the main, the user sees on their map in a split second the drift trend and can proceed in the right direction to reacquire the signal. One cannot manually input positions fast enough to do this realistically.

    Manual input can lend itself to keying errors and wild goose chases if one is not careful. I’ve witnessed that in the past with other fliers. I made one Ham flier very happy after he had a difficult recovery with a Ham band Beeline GPS. He manually input the last know position into a Garmin 60CsX from his D72A and took a half an hour to realize his mistake. I told him about the serial cable for the link to get the 72 to talk to his Garmin and he was a very happy camper the next launch. No more manual diddling. Kurt
     
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  3. Oct 19, 2019 #63

    VernK

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    Kurt, Do you remember where you saw the video? I have not seen it but I would like too.

    By the way, Kate is not an open source voice. I have to pay licensing fees to use it. However, there are other open source voices available. The ones I have heard are not as good as Kate in my opinion.
     
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  4. Oct 19, 2019 #64

    ksaves2

    ksaves2

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    Shoot no. I think if I’m not mistaken it was a staged flight out on the playa. Might have been a past BALLS launch. I tried a google search with a variety of keywords and didn’t get a hit. I think I might have seen the link on TRF. I remember they had the camera focused on the receiver screen the entire flight. I was impressed at the data recovery rate as opposed to the other consumer GPS trackers out there.

    Maybe another reader out there will see this thread and know where the link is. I’d like to study it again myself.
    Even a lowly 100mW 900Mhz GPS tracking system can be made to paint the positions live on a mapping application. Using the APRSIS32 tracking program one can open two instances of the program while using the local GPS inputs of both to read the incoming data stream from the tracker to paint it live on the map and then send the “local” position from the minimized 1st instance to the second open instance (using an internal network port) to paint the local position and the rocket on the same map. The only difficulty is I didn’t get as many rocket positions painted on the map as I would have liked. It later occurred to me that painting the local position might have been colliding with incoming rocket positions and didn’t get “painted”. Took me long enough to realize I should just paint my local position once on the map, then suspend that program and shut off the internal network so the incoming rocket positions have all the processing time to get painted. Once the rocket is down, I can turn the local position back on for the walk out to the recovery site.

    Bottom line is even an entry level system can be made to live track. With life, I haven’t been able to get back to experimenting. Prostate Ca in December ‘16 with surgery. Unfortunately there was local spread and 45 radiation treatments with a boost to the teeny tiny spot seen on choline PET scan next to the prostate bed where it used to be. Two years of Lupron shots. You ain’t been castrated untils one been chemically castrated!!! Three years out and last weeks PSA is .01 the limit of detection so I might have been successfully salvaged. Dad died in ‘17. He made it to 89 and had a great life though. My wife who was five years younger than me got a terminal diagnosis October 22nd, 2018 and died January 25th 2019. Lung cancer and never smoked in her life. I later discovered there is a Radon problem where we live and that didn’t need to be disclosed when we bought the house in ‘95. I tested after she was gone and the readings were 2 to 3 times higher than the upper limit of safety. Abatement installed and they guarantee <4 PiC/L. I see .3 now. My only regret in life is that we were ignorant of this.

    On top of this, TRA prefect dies and local prefecture is unsustainable due to lack of interest. Didn’t lose the flying site. The prefecture died due to lack of members. I can travel a little farther and fly with the QCRS folks though.

    Kate not Open Source? Well shoot, I could swear I heard a female voice that sounded like her available a long time ago in the Festival Speech server so I just assumed it was OS. Thanks for correcting me. Two years to retirement and I will be back! Kurt
     
    Last edited: Oct 20, 2019
  5. Oct 20, 2019 #65

    OverTheTop

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    You can increase immunity to the nearby RF transmitter by installing additional capacitors across each eMatch and battery. Something like 100nF ceramic capacitors is a reasonable thing to add, at the terminals on the altimeter board. This works because capacitors are a low impedance at high frequencies. Any RF picked up by the eMatch and battery leads (aka "antennas") is effectively shorted out by the capacitor. Without the capacitor there would be a significant RF voltage impressed across the terminals. That gets rectified by non-linear components in the altimeter and can radically change biases on ICs and transistors in the electronics, creating an internal EMC (electromagnetic compatibility) problem.

    Capacitors are good. OK? ;)


    Kurt: Take care. You have had a difficult time lately.
     
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  6. Oct 20, 2019 #66

    ksaves2

    ksaves2

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    Thanks, the alternative to capacitors is to simply use newer electronics that are relatively immune to Rf. All my Egg product devices in a bastidized testing regimen I did worked well and one can easily test as I outlined above.

    I still wouldn’t use an Adept 22 with Rf caps or no caps. Not worth the risk in my book to dork a flight. :) Doing O.K but saddened a bit everyday as I miss Sally and expect I will until they pull the sheet over my head. Don’t worry. No death wish on my end here. I may be still sad but am quite functional with all the local support I’ve had. Heck, I’m posting again so that’s a plus. Now all I have to do is get out there and do some flying. Got a local site 2 minutes from me I can do some up to G’s after they get the corn down from the surrounding fields. Kurt
     
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  7. Oct 20, 2019 #67

    OverTheTop

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    The more real-world savvy designers would include such capacitors, and/or other mitigation, on their products. You can't tell what is going to be sitting next to your designs so it behooves the designer to make efforts to have NOE (no observable effect) in an RF immunity situation.
     
  8. Oct 20, 2019 #68

    manixFan

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    Ah, got it. So in that respect the Featherweight would be considered a 'live mapper' in that it provides real-time heading and inclination to the rocket. The iFIP software has two simple graphic indicators to help you find your rocket in the sky - a heading and inclination indication that is green when you are pointing at the GPS location of the last packet. I've attached a cropped animated GIF below that shows this. When the arrow at the top of the screen is green, you are pointing at the right heading, when the circle at the middle left is green, your iPhone is tilted at the right inclination to the rocket. I suppose one could make a sighting tube and mount it to their iPhone and use it to look for their rocket during descent. Also note that it provides what I find to be very useful information, the descent rate and more importantly, the horizontal drift velocity. At BALLS this year we were seeing drift rates as high as 60-70 FPS at higher altitudes.

    The GIF is taken from a 54mm Mongoose clone (shortened) that went to about 24,385' on a CTI L805 at BALLS 2019. No drogue, recovered 7600' from launch site.


    Tony

    (Not sure if this plays correctly, but it is an animated GIF)
    54mm-Mongoose-BALLS.gif
     
    Last edited: Oct 20, 2019
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  9. Oct 20, 2019 #69

    ksaves2

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    The Featherweight system will find your rocket. It appears to have a live DF (direction finding) indicators in the software but currently no ability to pipe the GPS strings to live mapping software directly.
    That is a problem with Apple stuff. They control everything and being able to do that on their platform might be extremely difficult. I'll try to dig up some screensaves from past flights and post them again so you see what I mean. The beauty of a live map as one can get orientation at a glance. For instance, I was tracking a fellows Beeline APRS (Ham band) GPS tracker and it landed to the south on the range. OMG! he exclaimed, "I wonder if it landed on the road?" I didn't have to diddle with manual keying into some GPS mapping software, I just yelled out, "It landed north of the road, is still on the field and doesn't appear to being dragged by the wind." The rocket was close enough that I still had reception with it on the ground, the GPS tracker still had a lock and it was too far to see just where it was. Basically with manual input one it putting in the last known position and as long as they get it displayed on a map, they'll be able to plan a route to the rocket.

    I used the program GPS Rocket Locator for a flight that landed 1.6 miles away from me. At the time, the program didn't have downloadable maps that one could store on their device so they didn't have to have a live Internet connection. I just made the two dots come together but got my feet wet crossing 4 drainage ditches. It didn't occur to me to key the last known position into a mapping program and did a straight line recovery. If I had a live map, I would have seen instantly I could have driven to a spot onroad 75 feet from the rocket. I was flummoxed and if I had done the extra step, I would have seen there was a better route.

    With Ham GPS tracking on 400Mhz and 2 meter band using a D72a and a handheld Garmin 60 Cs(X) is one can scroll to a "flight director" screen to get a compass rose and bearing indicator to the rocket.
    It shows you how far to go, your speed and what time you'll get to the rocket site. I find it easier to keep the map screen up and make the two dots come together. This was doable in 2005 but cost over $1k with a Kenwood D7a(g) and the same Garmin units that were top of the line then. The Beeline GPS Ham band trackers were marketed back then. That's what got me hooked, no more guessing.
    Did a little RDF successfully but I liked the piece of mind knowing where my project is. Kurt
     
  10. Oct 20, 2019 #70

    manixFan

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    The Featherweight does have live 'RDF' indicators, with distance, heading, and inclination as shown in the screenshot above. It also provides full GPS info. While it's an inconvenience to have to manually enter the GPS coordinates into mapping software, that seems like a fairly trivial nit compared to the other real-time data I get during the flight. But when you are recovering a rocket in the middle of a planted field, the directional arrow and distance is a lifesaver.

    Below is a shot the receiver for the Featherweight system. I put it inside the case you see on the left and clip it to a belt loop. (Wallet included for scale.) No yagi antennas, no cables between units, no dongles, etc. Just bluetooth to my iPhone. I'm sure I would get better data during flight if I put it out away from my body but it's pretty hard to lose this way. When I get in the car I just put the case on the dashboard.

    Also below are shots of a recovery from LDRS this year - a 38mm MD CF Mongoose that went to over 15K'. Landed in the middle of a milo (or sorghum) field over a mile away. I kept the receiver clipped to my beptloop and just followed the direction arrow on my iPhone and walked right up to the rocket. Mapping software would not have been nearly as helpful in that instance.

    As I mentioned before, I had the Kenwood radio with the Garmin cable and a BRB. That's a great system for someone who really likes the nuts and bolts of using a HAM radio and all the associated fiddling around. We used a Kate 2.0 system for our big flight at BALLS, which tracked the rocket to over 13 miles away and had the last packet within 20 feet of where we found it. It's a phenomenal setup. But the reasonable cost and simplicity of a system like the Featherweight tracker is a good solution for the average flier who just wants to get their rockets back without a lot of expense or hassle.


    Tony

    entire receiver with a case I had on hand: (wallet for scale)
    receiver.jpg

    Field hiding my 38mm MD rocket:
    field.jpg

    Found using the 'live RDF' of the Featherweight system:
    field-recovery.jpg
     

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  11. Oct 21, 2019 #71

    cerving

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    Exactly what is it that you find hard to read? How could we improve it?
     
  12. Oct 21, 2019 #72

    Cameron Anderson

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    Logged my second flight in my AIM XTRA 2.0 yesterday. I'm very impressed with this system and curious why it more people don't use it/know about it.
     
  13. Oct 21, 2019 #73

    markg

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    Not OP, but I use Eggfinder in my rockets. The 3 sets of arrows on the LCD screen are confusing, I always need to refer back to the manual to figure out which arrow does what and frankly the manual doesn't really give a description of the screen setup.

    Looking at the manual now (http://eggtimerrocketry.com/wp-cont...finder_LCD-GPS_Assembly_Users_Guide_w_Pix.pdf), I'm pretty sure I just ignore the top line of the LCD and follow the double arrows on the bottom right beside the 'L:16'. The 'D' is not mentioned in the manual but I'm pretty sure it's distance, Feet or Meters?

    I haven't used the system since June, so I'm going on memory here. When walking to locate rocket, we are trying to get C/T to match right?

    Here's my attempt at trying to make the instructions more clear, please let me know what I got wrong :
    eggfinder LCD-GPS.JPG
    The other thing that would be good is if the LCD showed when it was connected to eggfinder even if it is not getting GPS signal. When I am testing eggfinder/LCD connection, it is a bit of a mystery if they connect until eggfinder gets GPS signal. I find myself pulling apart the LCD to check if the green LEDs are matching more than I'd like to.

    cheers - mark
     
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  14. Oct 21, 2019 #74

    cerving

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    Thanks for the feedback. Due to the limited number of characters on the display (16 characters x 2 lines) I can't make it as pretty as I'd like. Some people have created labels that go just above and below the display... maybe something like that would be helpful. I'll look into it. You are correct in that if you have the LCD-GPS module installed the only line you really need to look at is the bottom one... how far and which way to your rocket. The "D:" (distance) units are whatever you have them set up to be on the configuration screen, default is feet but you can change it to meters if you want. That goes for the altitude figure on the coordinate screen, too.

    There is an "I'm connected" indicator, the buzzer will give you a little double-beep every 2 seconds if you have a link but don't have a fix, starting from the "Waiting for Fix" screen and continuing through the navigation screens. Maybe a little blinking block in a corner or something like that would be a nice visual indicator of signal, too... currently it shows you how many seconds since your last fix and the quality of the current fix. Unfortunately the RSSI indicator from the Hope RF modules is not particularly useful, which is why I don't show it.
     
  15. Oct 21, 2019 #75

    Eric

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    I did several high flights this last weekend. The highest went to 14,700' and the main came out at apogee. The ground winds were 10mph and I drifted 5.92 miles.

    The Eggfinder Mini took me straight to it. I only use the bottom line of the heading screen. Distance from the rocket and direction I need to go. I only stopped receiving updates when the rocket landed and the receiver showed me to the last known position. The receiver showed over 24,000 feet away as I would already started driving over a mile in that direction.

    Completely impressed with the Mini using the standard antenna.

    Screenshot_2019-10-21-08-54-44.jpg Screenshot_2019-10-19-11-59-12.jpg
     
    Last edited: Oct 21, 2019
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  16. Oct 21, 2019 #76

    markg

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    Glad to hear of your experience Eric, this helps give me confidence for my out-of-sight eggfinder flights. For future reference, could you repost this over here:

    https://www.rocketryforum.com/threads/eggfinder-trs-how-high-far.148576/

    cheers - mark
     
  17. Oct 21, 2019 #77

    ksaves2

    ksaves2

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    Cameron, Not to get into a pi##ing contest but since it's on the 70cm Ham band, technically one in the US should have a Ham technician license to operate. Am not going to argue that but I think the cost is likely the issue.
    I've noted that users that fly them, like them. In reality, I highly doubt anyone from the FCC (Federal Cookie Commission) is going to try to track down a 70cm band, 50mW GPS tracker. (Raincoat on now.)

    I was messing around with super cheap SDR radios for awhile and gave up as I couldn't get my callsign programmed into the GPS strings to stay legal. The idea of a $25.00 "disposable" GPS tracker was very enticing to me.
    Have a devastating CATO or lawn dart and no big deal. Try that with a $256.00 Beeline GPS. Now that hurts the wallet big time. Kurt
     
  18. Oct 21, 2019 #78

    Cameron Anderson

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    Cost is no more than other systems available today. And in some ways I think it's more capable than those other systems, HAM requirement aside.
     

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