Have a look at my flight data? GPS questions... (warning long rambling post)

[Faroutspacenut]

Hi Everyone,

With my recent L1 cert in hand, I was excited to finally fly my LOC Vulcanite this past weekend at ROCstock. The test flight went ok (G80NT) - plenty stable but I had some issues with my chute release (as in it didn't) so it landed with a reefed chute from 1900' feet. Not even a scratch on the rocket, so I felt pretty good about the strength of the build. Since it was the maiden flight, it got to earn its name on that one: "Free Fall".

So on to the main event.

I had a few goals with the next flight:

- Fly my first I motor - AT I280DM. (I used the full 14 sec delay)
- Mile high or more (OR simmed 6,000'+, ThrustCurve iffy)
- Break Mach (OR iffy, ThrustCurve no way)
- Attempt GPS tracking for the first time.

I've been following a "one skill at a time" path, and tracking is next on the list of things to learn. For the most part, the flight would be mostly in visual range so it seemed a good opportunity to test out my system.

On board this flight I had:
Jolly Logic Altimeter 3
Jolly Logic Chute release (set at 400')
Altus Metrium Tele GPS tracker
For picking up the GPS signal, I'm using a Yaesu FT1XD with a 3 element Yagi Antenna.
iPhone for manually inputting GPS coordinates (google maps)

I'm still struggling a little with the HT and all of the ARPS settings, but I managed to get it working and a lock on the tracker on the pad. The gps coordinates showing up on the HT seemed to be correct for the launch site. So far so good.

It was a great looking flight. Wow I love those sparky motors. And loud! This is going to get expensive!

I could see the rocket land, so no real worry about losing it. We were able to get a good clear signal from the tracker and the supposed GPS coordinates at the landing location.

Here's a shot of the tracker's GPS coordinates on the HT. Sorry that it's barely visible.



It says N 34" 29.71' W 116" 57.64'

- First Question/problem: I could not figure out how to get these numbers into google maps to show me where the rocket is. Is there a better map app for this? Is there a standard/easy format to enter these exact coordinates into google maps? (I don't own any Android devices, so for now my understanding is I have to do it the hard way.)

I gave up on having my map take me to the rocket - not a big deal as I could see where it landed but I would have been pulling hair if I hadn't.

Upon recovery, I downloaded the flight data from the JL A3. According to the data, I went over a mile (6,654') but just came a tiny bit shy of breaking mach (757 mph). The chart in this view doesn't really show the chute release deploying at 400' but it does when I zoom in using the app. I did however find the 4fps landing speed a little unusual.



The GPS Data tells a different story. I expected the data from the GPS would not be as accurate as the altimeter, but curious to see what you all think of the considerable difference. Could the Altimeter data be wrong?



Only 3094' and 200 mph slower than my JL3 indicates. Could this perhaps have to with the fact that our launch site is 2800 feet above sea level?

That being said, based on the gps data, the last reported location seems accurate. When I plugged them into Google Earth, it made this nice flight path for me:



One strange anomaly is the straight line connecting my home in Glendale to the launch location. Must have had some data on it from when I was testing it out at home and included it as part of the flight?

So the good news is that as far as the TeleGPS goes, the tracking works great. I love how small it is and it's so far easy to use.

Second Question/Problem: The coordinates displayed on my radio don't match what I downloaded from the tracker. Close, but seemingly not the same. This confused me since the numbers on the radio were being sent by the tracker... so can anyone explain why this is? Do I have something set incorrectly on the HT?

TeleGPS N 34º 29.738574' W 116º 57.462420' vs Yaesu N 34" 29.71' W 116" 57.64'

I'm still a major noob to all things GPS, so any insight here is appreciated. I'm building a Rockety Warehouse 38 Special that will definitely need a tracker, so I'm hoping to get the bugs worked out before putting that one up.

Thanks for reading, and look forward as always to your opinions and advice.

(more flight data)

View attachment Info.pdf

(and the launch!)
[video]vimeo.com/243262804[/video]

 

[Wayco]

Although I use another system for GPS, if you want an easy program to insert your coordinates into, try Motion-X. You can adjust the format of the coordinates to match what you are getting on your Yaesu, making it easier to input.
Make sure you have the same Datum on both devices, Google maps uses wgs84, not sure about your TeleGPS.
I was at ROCstock last weekend, really enjoyed that launch. Hope you can figure out your systems, GPS tracking is a great way to recover rockets, I'm using the Eggfinder and Rocket Locator on an Android phone, my 3" Blackstar and Jughead, my 5" Jart were both recovered at that launch with them.

 

[ksaves2]

Dig into the FT1 instructions and set your units to degrees, decimal degrees. That's something like 44.3445. That will simplify your situation immensely as far as manual data transfer is concerned. Also, read the sticky at the top of the column. Specifically the topic on setting up APRS trackers. I don't believe one can easily get the waypoints out of the FT1 at this time. The out of production VX8GR could connect a cable and send the serial Waypoint information to a handheld mapping GPS or laptop computer.
The combination that can't be beat for portable tracking on the APRS side is the Kenwood D72a or D 74 if one is sitting on piles of gold and the simple serial cable connected to a Garmin 60cs or 60csx. A Kenwood d74 would be able to track just about anything. That comes with a very steep price though. The d72a is more affordable. If using one of the interfaced Garmins, I set the d72a to display theAPRS altitude while the position and range is shown on the map on the Garmin handheld. All this is done in real time.
If one experiences tracking in this fashion they won't want to do it any other way.
The egg finders et al or nmea trackers aren't there yet as far as a full-featured live map navigation suite.
NMEA trackers will find your rocket no doubt and I've used them a lot. If I'm in a lazy mood can't beat the beeline GPS, Kenwood d72a interfaced to a handheld Garmin.
Also losing a $70 egg finder is easier to swallow than a beeline GPS. Lose it you say? Yeah, if there's a ballistic flight or a main at a very high apogee that gets caught in fast upper winds. Oh, you can lose one. Kurt

 

[blackjack2564]

Or just get a Altrus Tele BT base unit. Use with wire or Yagi antenna.

It will bluetooth data directly to an android phone or if like me [have a caveman phone] bought a cheap android tablet from Best buy. [6in screen] 34.00

It's wi-fi so you can download Rocket Locater [free app] when near your wi-fi or at home. Download maps for whatever launch site you fly at. Tele BT has many of club site already pre-loaded.

Any how you don't need any phone or wi-fi service at the launch. Maps preloaded, go fly.

Since tablet/phone has GPS in it. It will show both rocket location & your location. Will walk you right to rocket.
Just like using a GPS in car to get somewhere!

 

[cerving]

The Eggfinders will Bluetooth into Android, either with the RX "dongle" or by adding a Bluetooth module to the LCD receiver. I like the latter... you get the convenience of the map and live track with the assurance that if you lose your Bluetooth feed you're still going to be able to get your rocket back.

 

[ksaves2]

Or just get a Altrus Tele BT base unit. Use with wire or Yagi antenna.

It will bluetooth data directly to an android phone or if like me [have a caveman phone] bought a cheap android tablet from Best buy. [6in screen] 34.00

It's wi-fi so you can download Rocket Locater [free app] when near your wi-fi or at home. Download maps for whatever launch site you fly at. Tele BT has many of club site already pre-loaded.

Any how you don't need any phone or wi-fi service at the launch. Maps preloaded, go fly.

Since tablet/phone has GPS in it. It will show both rocket location & your location. Will walk you right to rocket.
Just like using a GPS in car to get somewhere!

Got a Tele-GPS and a Tele-BT too. Shoot if the Tele-BT did APRS too we'd be REALLY cook'in. Alas, Keith told me it's just a simple digital receiver for their digital protocol. That said, their products can also transmit position via APRS so if one
wants a small GPS tracker on 70cm they can use their APRS receivers (D72a and others) to find their Altus projects. The Tele-BT though is extremely nice and recommended. Kurt

 

[Faroutspacenut]

Thanks everyone for the very helpful feedback. Ideally I would not like to buy a new phone or tablet - or a different tracker. Primary goal for me now is to get the setup I currently have working optimally rather than assembling the optimal setup. At some point I'll probably look into a more robust turnkey system. That said, Jim I'm definitely going to look into a cheap tablet like you suggest. That might make springing for the TeleBT a little easier. I'm going to try to re-congigure the HT settings as Kevin suggests and Motion-X as Wayco suggests. If I can get through a few more launches with what I have, I can probably justify spending a little more $$$.

 

[ksaves2]

Thanks everyone for the very helpful feedback. Ideally I would not like to buy a new phone or tablet - or a different tracker. Primary goal for me now is to get the setup I currently have working optimally rather than assembling the optimal setup. At some point I'll probably look into a more robust turnkey system. That said, Jim I'm definitely going to look into a cheap tablet like you suggest. That might make springing for the TeleBT a little easier. I'm going to try to re-congigure the HT settings as Kevin suggests and Motion-X as Wayco suggests. If I can get through a few more launches with what I have, I can probably justify spending a little more $$$.

Get an Android device with an onboard GPS,Wifi and Bluetooth. Get GPS Rocket Locator and download maps to memory for offline use. GPSRL is not perfect by any means but can give you a visual representation. It doesn't do bread crumbing meaning it
doesn't paint the rocket positions on the screen so you can see where it has been. It's just a straight line from you to the last known position.

Nonetheless, do some flight with the tracker and motors you know will keep your rocket close so you can trial and refine your technique. Once confident, then punch it out of sight.

Remember a good receive antenna and blowing the main up as high as you can tolerate is desirable. Once the rocket settles down under the main chute, the positions are more reliably decoded. Altitude is your friend as far as Rf propagation is concerned.
Kurt

 

[Handeman]

doesn't paint the rocket positions on the screen so you can see where it has been. It's just a straight line from you to the last known position.

It certainly did for me. I had a dark blue line that tracked the rocket from the RSO, to the pad, and it's ground track during flight. It also had a straight white line between the blue dot of the phone and the red pin where the rocket was.

 

[ksaves2]

It certainly did for me. I had a dark blue line that tracked the rocket from the RSO, to the pad, and it's ground track during flight. It also had a straight white line between the blue dot of the phone and the red pin where the rocket was.

Well thank you,

I stand "corrected" here by Mr. Handeman. It does paint paint the blue line of the red pushpin. I've been running the hacked APRS software awhile and have "breadcrumbing" on the brain where there is some information (like altitude) pasted on some of the positions. (I suspect the altitudes might be inaccurate but I need to really punch an NMEA tracker up really high and see what kind of map it paints.) Those APRSISCE/32 screens are from a live flight and not
taking a logfile and putting it into some software after recovery



Creeipes, I even have screenshots of that in my files. The bread crumbing I was fixated on is like the left picture. Admittedly I haven't flown GPSRL in awhile. The GPSRL shots above are with a 3DR tracker system CORZERO has
had a lot of luck with. I've been toying with the allegedly more "powerful" version of the 3DR radios and find the Rf can interfere with the GPS with the 400Mhz Rf range. I can't shrink wrap the GPS to the radio without suffering a loss of
GPS signals. They're attenuated significantly. The 900Mhz rigs seem to tolerate this better. The 3DR radios have a 2 way link although I've read where the base station can be set to receive only. The two way thing I believe cuts down on the potential range as mentioned by some drone fliers whereas we want position fixes from as long a range as possible and don't care about sending data or commands to the air module. Oh, some drone sites mention the dubious power output of the alleged
500mW 3DR rigs.

The only potential advantage with 3DR would have been a $30.00 GPS tracker. Crash it or lose it and a lot easier to swallow than dorking an EggFinder, T3 or Beeline GPS. Although I'd rather lose an EggFinder as opposed to a Beeline GPS tracker any day! (Did that on my first GPS tracked flight 12 years ago.)

Tooling with the GPS addon to the EggFinder LCD base. I got it on top of a Black Aero case. I put my switches off to the side so there was room on the top for the GPS. Did a drive around and some brief foot testing and it works. I really have to
read the instructions and get my brain into "compass" mode on reading the display and the LCD can still be paired up with GPS Rocket Locator or any other app one might want to use.

I recommend this if one doesn't want to keep inputting data into a handheld GPS barring that, it's great backup to have in case one's primary tracking app croaks. Kurt