# Google Earth Realtime APRS tracking?

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#### Kip_Daugirdas

##### Well-Known Member
Question: Has anyone done realtime APRS tracking using Google Earth?

To elaborate, what I have in mind is a realtime trajectory plot in Google Earth. This plot would look just like a .kml file that you can import post flight - except it would be created in realtime.

I know there's an app called W2APRS where you can connect your Kenwood D72a to an Android tablet and see in Google maps the realtime location of an APRS transmitter.

I'm interested in something like this but in Google Earth.

#### SpaceManMat

##### Space Nut
Not sure about APRS but GPS Splitter can bring up a real time KML in Google earth from an incoming NMEA stream as well as send it to other places. I use the free version on my laptop in conjunction with my egg finder.

https://www.eltima.com/products/gps-splitter/

#### ksaves2

I believe for most real time APRS tracking with Google Earth, one would need online access and the app you describe above. APRSIS32 used to be able to cache
MapQuest photomaps (old but usable) but that has gone away. GPS Rocket Locator can cache maps for NMEA trackers, EggFinder, Missileworks and the old
Arts system. My newer cellphone Android 5.1.1 doesn't seem to want to cache google maps with any appreciable zoom level anymore so I don't know if that option is viable anymore or it's just my device.

My suggestion is to avoid cables of the USB type as they easily get torn out and removed unless you put everything in a small box.

Photomaps are nice but there are a lot of unencumbered Open Source maps one can store on their device and not have to rely on a live Internet access.

That W2APRS app you point out above is compatible with a Kenwood D74 with a Bluetooth link to your tablet but holy molee it's pushing $600 to$700!!
Too rich for my taste. A USB cable to a Windows tablet from a D72 would work with a lot of ham tracking programs but again, I don't think they

It is possible to recover a rocket without maps. Two points and a line on a screen is all that's needed but one can't plan a recovery very well then.
I did it once and found out I could have driven on road to a close place to park and just walk a short distance to the rocket rather than hike straight line through
some obstacles.

APRS Droid is workable with a Bluetooth connection to a Mobilink TNC connected by wire to any H/T. One has to have their gain settings correct and I find on
walking recovery I have to "transmit" my local position on air to get my local position to "move" on the map so I can see if I am proceeding in the right direction.
A local distraction but doable.

With NMEA trackers and two instances of APRSIS32 on a tablet, I just walk and my position is plotted every 10 to 15 seconds automatically.

The altitude from the EggFinders are less than to be desired in this setup and the inaccuracy may be compounded by the tracking software. Nonetheless, the
ground plots are dead on. Kurt

#### mccordmw

##### Well-Known Member
Isn't real time tracking possible using the Rocket Locator app? I have an Eggfinder where my receiver transmits to my Samsung Galaxy S7 via Bluetooth, and the Rocket Locator app shows my current location on Google Maps via normal GPS plus the location of the rocket via Eggfinder.

Not Google Earth, but Google Maps. Is it achieving what you want to get? Or maybe I'm understanding the question and oversimplifying?

#### Kip_Daugirdas

##### Well-Known Member
Yeah I'm not using this for finding the rocket post flight. I'll still do that with the last known coordinates and punching those into Google Maps.

Instead it's more for inflight monitoring on out of sight flights - seeing if my drogue deployed, main, downrange distance, etc.

There's a lot you can tell just from a flight plot. For reference I'm using a D72a for receiving and a Beeline 70cm 100mW GPS.

#### ksaves2

Isn't real time tracking possible using the Rocket Locator app? I have an Eggfinder where my receiver transmits to my Samsung Galaxy S7 via Bluetooth, and the Rocket Locator app shows my current location on Google Maps via normal GPS plus the location of the rocket via Eggfinder.

Not Google Earth, but Google Maps. Is it achieving what you want to get? Or maybe I'm understanding the question and oversimplifying?
Yes you are correct. I've stored the maps on two dual boot Android/Windows tablets but haven't tried GPS Rocket Locator with the stored maps yet on those devices. I like the bread crumb trail I get with APRSIS32.
I just sprung for one of those "returned" BLU phones and for some weird reason, I can't get GPS Rocket Locator to store the maps off line. I don't know if I have a file name problem or what.

GPS Rocket Locator doesn't leave a breadcrumb trail which is OK as long as you are staring at it as your primary tracking device. I had it setup as a backup station with its own EF LCD receiver with it sitting on top of
my SUV roof but didn't get a good track. I was using APRSIS32 as my primary reception station and a patch antenna so there may have been reception problems with the GPSRL setup.

Oh, if anyone wants to track one EggFinder with two EggFinder LCD receivers with bluetooth capability, you have to bond the EFLCD to one tablet/device and then walk out of bluetooth range of your 1st system to bond and setup your second
receive station. I tried it with both devices in B/T range and got weird behavior.

Once you have the two systems bonded, you can bring the receiving stations close to each other. Why would on do this? I wanted to test GPSRL and APRSIS32 at the same time. Unfortunately, I couldn't pay attention to both as the same time and there wasn't an experienced user who could use the GPSRL program. Kurt

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#### ksaves2

Ok,

Remember, tracking via Ham Radio APRS is different than the unlicensed NMEA trackers. The Sainsonic AP510 is a 1 watt ham license required tracker which can be tuned to the National 144.390 frequency but be aware one will readily
tick off the APRS folks if sending packet over the air on 144.390 every 5 seconds.

I you were trying to get the 70cm BLGPS into the APRS-IS system one would have to cross band repeat the data on 2 meters to hit a station that could gate the packet to the internet. If you have a device that has wireless internet it would be easier to do.
Kurt

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#### ksaves2

I was referring getting packets to aprs.fi using radio audio to Pocket Packet (Iphone), or APRS droid. There is a cable hack out there for connecting audio to iPhones. There is also the mobil linkd TNC (https://www.mobilinkd.com/) for Android phones. The cell coverage on the playa is good enough for this depending on your provider. Someone from Aeropac did some signal testing and they were getting like 3-5 Mbps on Verizon I think at XPRS.
Right, That's fine if you have internet service on your device. My personal preference (and I know folks prefer other options) is to have a completely self-contained tracking system with no dependency on the outside for maps.
Hence, I'm not interested in using Google Maps because it is not easily done for me. Some have said Google maps can be cached but unless I can be certain the maps aren't overwritten, I prefer a more reliable map
presentation even though it may not be with pretty photomaps. Yeah, it's cool to see the rocket might have landed in a ditch, next to a barn or in a tree but one will find out soon enough when they arrive on scene.

I really forgot to clarify if one does indeed receive APRS position packets at a high rate, once every 5 seconds and directly pipe it to the APRS-IS through an internet connection, no one will mind. The APRS mavens/Nazis get their chains jerked
if one is sending position packets over the 144.390 National APRS frequency via Rf and clogging up the digipeaters. I know 'cause I used to monitor for high altitude balloon trackers and if the fliers chose a high rate position updating with poor path settings, it would really tick people off in the APRS groups. A rocket might be able to get away with a WIDE2-1 path over Rf as the flights are relatively speaking short but you never know who is monitoring.

Really, EggFinders are in the 420 to 450Mhz range so no danger to the 2 meter band. Some 2 meter trackers can be tuned to a different frequency off 144.390 so one can track locally without disturbing the APRS network
via Rf. Kurt

#### r66astro

##### Well-Known Member
TRF Supporter
I have been a ham for many years so it seemed easiest to go that route. Already had Tnc's. So I bought bigRedBee 70 cm 100 mw transmitter. Transceiver is a cheap Baofeng UV-5RV2. I have to take a Laptop with me, I just plug in the last GPS numbers into hand held and walk to rocket.
Bill
KG9ES

#### ksaves2

I have been a ham for many years so it seemed easiest to go that route. Already had Tnc's. So I bought bigRedBee 70 cm 100 mw transmitter. Transceiver is a cheap Baofeng UV-5RV2. I have to take a Laptop with me, I just plug in the last GPS numbers into hand held and walk to rocket.
Bill
KG9ES
That works as long as one uses the correct units. If you've been doing it that way for a long time you have the practice. I've seen people wandering about otherwise. If the rocket drifts quite a distance away and the trackers ground footprint is small, one might not be close enough to get a new position fix.
Live map tracking can usually get enough data points to show a drift trend while the rocket is coming in down low so one knows a direction to proceed.

If you're using the 100mW BLGPS you of course will have quite a large ground footprint and should not have to worry.

APRS tracking with Xastir, APRSIS32 or even the old UIView can get one a rocket icon that shows APRS altitude, ground speed, position and direction of
travel right next to the icon. So far, I've found the altitude reporting of the Beeline GPS chipsets more relevant than the EggFinders with rocket flights.
One must remember the EggFinders are a rocket locating device and not advertised as a telemetry unit. It assists greatly in recovery and well one can always
get the flight data from the deployment electronics. Kurt

#### r66astro

##### Well-Known Member
TRF Supporter
That works as long as one uses the correct units. If you've been doing it that way for a long time you have the practice. I've seen people wandering about otherwise. If the rocket drifts quite a distance away and the trackers ground footprint is small, one might not be close enough to get a new position fix.
Live map tracking can usually get enough data points to show a drift trend while the rocket is coming in down low so one knows a direction to proceed.

If you're using the 100mW BLGPS you of course will have quite a large ground footprint and should not have to worry.

APRS tracking with Xastir, APRSIS32 or even the old UIView can get one a rocket icon that shows APRS altitude, ground speed, position and direction of
travel right next to the icon. So far, I've found the altitude reporting of the Beeline GPS chipsets more relevant than the EggFinders with rocket flights.
One must remember the EggFinders are a rocket locating device and not advertised as a telemetry unit. It assists greatly in recovery and well one can always
get the flight data from the deployment electronics. Kurt
I have mapping stuff. Mostly Linux some cross platform.. I am too lazy to download maps. In the end I still would use hand held gps. had the neighbor hide the nose cone (trans inside).
We live in the country, my hand held (old garmin 12) gets me within a few feet.. I have bought on Amazon some of those cheap gps things. Bought several sims, bought time for sims and I have yet been able to get the things to work
Bill

#### bigredbee

##### Well-Known Member
I've written filters before that take the output from the TH-D72 and converted it into a .kml file for google earth. Or, as others have mentioned, use mapping programs designed for APRS.

Greg

#### ksaves2

I have mapping stuff. Mostly Linux some cross platform.. I am too lazy to download maps. In the end I still would use hand held gps. had the neighbor hide the nose cone (trans inside).
We live in the country, my hand held (old garmin 12) gets me within a few feet.. I have bought on Amazon some of those cheap gps things. Bought several sims, bought time for sims and I have yet been able to get the things to work
Bill
Yeah, When I'm lazy and want to simply track the Beeline GPS stuff I use a simple serial cable like this for example: https://www.navsphere.com/GPS-Cables/rk.php
plug it into the jack on my D72A and the socket on my used Garmin 60CsX. I lucked out and got a used 60CsX on the cheap and the guy said he only used it 4 times. It looked pristine. Downloaded open source maps for it: https://garmin.openstreetmap.nl/ and I have a quick and easy rocket tracking system that
computes a tracking solution in real time during a flight. The maps don't have a good database for restaurants, gas stations, stores etc. but the maps are pretty good.

I set the monitoring screen on the D72A to display the altitude and orient my 60CsX so I can tell where the rocket is at in flight so I can try to get a visual when the main is expected to occur. Just add the ground elevation to the expected main deployment and that's
the altitude display on the D72A one can expect the main to deploy.

With the low powered BLGPS, one usually loses the signal once it's down but as I proceed to the last received position either following the map or scrolling to the
HSI (Heading Situation Indicator) screen on the 60CsX I periodically open the squelch on the D72A and turn up the volume. I can sometimes hear the squawking of the BLGPS that is too faint to decode but I know I'm on the right track to pick up a new position eventually. Reassuring the tracker is intact and survived the flight.

Prices of the D72A have come down a bit and a 60Cs or 60CsX can be had used on ebay. I highly recommend this if one just simply wants an APRS tracking solution without the hassle of a laptop or tablet.

Though, small tablets are workable with Windows APRS tracking programs and a D74A has Bluetooth capability. At \$600.00 too rich for my taste.
Doesn't include the cost of the tablet though they can be pretty cheap.

Kurt

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#### r66astro

##### Well-Known Member
TRF Supporter
HSI? been awhile since I have heard that,, I am CFI rotary instrument se Land. I'll check out the maps you mention. I just hand load #s in gps. too lazy to buy or make cable. If my Garmin 430 was so big I'd use it! has ifr charts. so you have the 10mw 70cm? I emailed (if I remember correctly Brian at the BEE) told him what I was using for, and he recommend the 100mw.
What ever his name a great guy to work with. Answered my email very fast and shipped same day.
Bill

#### Kip_Daugirdas

##### Well-Known Member
I've written filters before that take the output from the TH-D72 and converted it into a .kml file for google earth. Or, as others have mentioned, use mapping programs designed for APRS.

Greg
So what I would need to make is a program that could continuously reload the .kml information. Do you have those filters posted Greg?