LAMA

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jch
Posts: 10
Joined: Thu Jan 23, 2020 8:04 pm

LAMA

Post by jch » Tue Mar 03, 2020 8:26 am

LAMA

Tracking
- Tracking is available at http://egm.cloud/balon/.
- Only flight path based on received GPS coordinates is available now. I will add table showing other data later today.

Last contact
Last message (as of now) lacked coordinates, so we don't know where the probe is, but it was received at 2020-03-03T04:09:48.019582371Z.

Code: Select all

{"device_id":"balloon","raw":"OUtgAAAAAAAAAAAAO3fQAAAAAAAAAAAAOvigAAAAAAAAAAAAPJkIAAAAAAAAAAAA","records":"[map[altitude:0 battery:2290 latitude:0 longitude:0 solar:1820 temperature:0 timestamp:0] map[altitude:0 battery:2375 latitude:0 longitude:0 solar:3810 temperature:0 timestamp:0] map[battery:2355 latitude:0 longitude:0 solar:3940 temperature:0 timestamp:0 altitude:0] map[temperature:0 timestamp:0 altitude:0 battery:2420 latitude:0 longitude:0 solar:4005]]","time":"2020-03-03T04:09:48.019582371Z"}]
More details about team and probe will be added later today.

jch
Posts: 10
Joined: Thu Jan 23, 2020 8:04 pm

Re: LAMA

Post by jch » Tue Mar 03, 2020 10:19 pm

News
I have updated tracking page (http://egm.cloud/balon/) to include more information:
- Table showing all data sent by TTN network (this includes packets without valid GPS position).
- Chart showing plottable data (altitude, voltages, time to fix) changing over time.

Details
I guess that data log table might be confusing, so small explanation is needed. Each of the packets actually contains 4 records, normally these are current one and then 3 historical 5 minutes apart (so that would be -5, -10 and -15 minutes from now). If the probe sleeps for longer time for some reason (e.g. capacitor voltage is too low for MCU and LoRa to operate, these records might be much older.

As there is no timestamp or even counter (hindsight 20/20) in the data records (not to be confused with packets, 1 packet = 4 data records) when we do not have GPS fix, it is not trivial to restore historical data properly. Therefore I have opted to plot only current (last) records in the chart. But adding these would not add much value anyway, it would match interpolated curve very closely.

We have originally planned to transmit temperature as well. Unfortunately we have failed to bring temperature sensor to life so we have used this field to transmit information about time to fix instead. This data field is still incorrectly labeled as temperature in previous post, sorry for possible confusion.

Conclusion
I was quite surprised that the probe was able to keep transmitting all night (lowest capacitor voltage was about 2,3 V which is still about 0,3 V above LDO cutoff) before actually catching morning light again. Unfortunately TTN coverage in this part of world is not that great, so we might have to wait few days before receiving something again. Well, if it's still floating...

jch
Posts: 10
Joined: Thu Jan 23, 2020 8:04 pm

Re: LAMA

Post by jch » Wed Mar 04, 2020 7:06 am

It's still alive! Last contact as of now was at 2020-03-04T00:31:17.53497973Z, so after approximately 37,2 hours of flight time.

Unfortunately no GPS position this time and I still don't have TTN metadata that would include information about gateways that received these messages, so we are clueless where the probe is.

w_LAMA
Posts: 2
Joined: Wed Mar 04, 2020 9:10 am

Re: LAMA

Post by w_LAMA » Wed Mar 04, 2020 2:08 pm

Little update:

we retrieved a few GPS positions from Iran, we took a turn above the Caspian Sea and heading south right now. Due to weather information on windy.com, we will continue to the east through Pakistan and Afghanistan and then hopefully above India, there should be much more LoRa TTN gateways. Praise the sun that we will not end up in Russia.

Image

w_LAMA
Posts: 2
Joined: Wed Mar 04, 2020 9:10 am

Re: LAMA

Post by w_LAMA » Thu Mar 05, 2020 6:58 am

During the night our balloon crossed Iran, so far we are flying according to the flight plan and we are heading to India. Flight plan is based on HYSPLIT trajectory model simulations which are optimized for balloon flights.

The flight level is 7800 m above sea and total flight time right now is 65 hours. It looks promising.

Last update: 2020-03-05T04:40:49.53 UTC
Last location: 26.7052 59.5102

You can watch us here: http://egm.cloud/balon/

jch
Posts: 10
Joined: Thu Jan 23, 2020 8:04 pm

Re: LAMA

Post by jch » Thu Mar 05, 2020 7:07 am

HYSPLIT prediction based on last known position:
hysplit-26.7052-59.5102.gif
hysplit-26.7052-59.5102.gif (52.35 KiB) Viewed 1209 times

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