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Is the Spark fluorescent under UV / blacklight?

yeoldesparky

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Sep 14, 2018
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Lost my Spark, white version, in a forested area with dense underbrush, ground cover and felled trees.

I can't see into the shadows below the brush in daytime sunlight. Going over the area with a bright flashlight after dark helped a lot but was still unsuccessful. If the Spark fluoresces under UV, it might be worth it for me to go over the area again with a UV light at night.

If you happen to have both a Spark and a UV light, it would be much appreciated if you could check both the top and bottom sides and let me know :)

Helpful information includes the color of your Spark and the brand, model and frequency of your UV light, and visibility at various distances from the light.
 

TangoMango

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Jul 31, 2018
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Lost my Spark, white version, in a forested area with dense underbrush, ground cover and felled trees.

I can't see into the shadows below the brush in daytime sunlight. Going over the area with a bright flashlight after dark helped a lot but was still unsuccessful. If the Spark fluoresces under UV, it might be worth it for me to go over the area again with a UV light at night.

If you happen to have both a Spark and a UV light, it would be much appreciated if you could check both the top and bottom sides and let me know :)

Helpful information includes the color of your Spark and the brand, model and frequency of your UV light, and visibility at various distances from the light.
I would guess if you've the White top Spark this may work.

You've tried "Find my drone" in the DJI Go App (will display last known location based on the last sent prior to loss of battery) I used this and found my drone in a wooded area at about a 5 meter distance from where the ping located.
 
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yeoldesparky

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I would guess if you've the White top Spark this may work.

You've tried "Find my drone" in the DJI Go App (will display last known location based on the last sent prior to loss of battery) I used this and found my drone in a wooded area at about a 5 meter distance from where the ping located.
I had no luck with Find My Drone, but thanks for the tip. My connection with the drone suddenly dropped out at a shorter range than I've had any trouble with before. Video was showing the drone flying around 30 ft above ground and with no obstacles. Find My Drone reports the location where the connection dropped out, and I've searched there, as well as at the RTH location, which was 500 ft away from where I lost the connection, and in the same forested area. The drone reported battery at 24% at the last received location. I had RTH elevation set to 300 ft.
 

Defens

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Aug 15, 2018
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Are you able to connect now at all? I lost my Mavic in some brush on my property after an altercation with some tree limbs above. The sound and flashing lights on the Mavic allowed me to home right in on it.
 

quad

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Sep 6, 2018
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Are you able to connect now at all? I lost my Mavic in some brush on my property after an altercation with some tree limbs above. The sound and flashing lights on the Mavic allowed me to home right in on it.
under the light from an uv light the white body does not fluoresce, but it does show very brightly in the dark under the light from a flashlight. it probably would be worth your trouble to go back out after dark with a strong flashlight and a couple friends with good night vision.
 
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yeoldesparky

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It's possible to extract the aircraft's GPS position from the flight data within the DJI app. By entering those coordinates into Google Maps you can really narrow down the search area.
Good luck!
Did that already, but thank you for the tip. I uploaded the telemetry to Google's My Maps, then plotted out the lost connection and RTH points, and added search boxes. Then tracked my location with GPS while searching.
 

Spark 317

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Did that already, but thank you for the tip. I uploaded the telemetry to Google's My Maps, then plotted out the lost connection and RTH points, and added search boxes. Then tracked my location with GPS while searching.

Just a thought.

You might try to get detailed weather information on that day and expand your search in the wind direction should the Spark switched to Atti-mode and drifted with the wind ?
 
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yeoldesparky

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under the light from an uv light the white body does not fluoresce, but it does show very brightly in the dark under the light from a flashlight. it probably would be worth your trouble to go back out after dark with a strong flashlight and a couple friends with good night vision.
Thank you for the info! Much appreciated. Very bright flashlight search at night did not work for me. Maybe it ended up upside down, in which case the matte black underside certainly isn't helping. If I ever get another drone, I'll make sure to put some reflective tape on both the top and bottom.
 

yeoldesparky

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Just a thought.

You might try to get detailed weather information on that day and expand your search in the wind direction should the Spark switched to Atti-mode and drifted with the wind ?
Interesting idea. I checked the flight data now to see if I could find some indication of trouble finding satellites, but it looks ok to me. The flight data, which has 4000 records for that flight, has two fields that look relevant, gpsNum and gpsLevel. gpsNum, which looks like the number of satellites being used, starts out at 7 before takeoff, generally increases over the time of the flight, and is at 14 at the time of lost connection. gpsLevel, which looks like an estimate of the GPS positioning quality, starts out at 1 and ends at 5.
 

Buddy411

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I feel for you. I lost a quad in some thick brush along the edge of a swamp... Took me 4-5 outings in the thorny thickets before I found it. Yep it was RIGHT at the entrance just a foot from my make-shift "trail"... must have walked passed it a bunch of times. :rolleyes: GOOD LUCK!
 
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graywoulf

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I plan on cutting small strips of white reflective tape to attach to the top, bottom and sides of my Spark. That way it could be located at night with a simple flashlight. Even from a good distance. I thought about using the UV idea and a UV flashlight but if I am already out in the dark looking for mine (and I hope that never happens) then I will have an advantage of seeing where I am going as well. Just a thought.
 
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yeoldesparky

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I plan on cutting small strips of white reflective tape to attach to the top, bottom and sides of my Spark. That way it could be located at night with a simple flashlight. Even from a good distance. I thought about using the UV idea and a UV flashlight but if I am already out in the dark looking for mine (and I hope that never happens) then I will have an advantage of seeing where I am going as well. Just a thought.
Orange reflective tape seems to be the way to go. Wish I had done that :)
 

yeoldesparky

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Thanks for all the tips and support, guys!

I've given up on my search. My take on it is that the Spark ended up upside down in a thicket which would make it next to impossible to find, given its matte black underside.

I feel like DJI should do a bit more to help finding their drones. Some reflective areas on there seems likely to have made the difference in my case. If I get another drone, I'll certainly put some on there. Another simple option that could be helpful is a Bluetooth tag. They're available for less than $2 on eBay, small enough to be fasted on the drone without interfering with anything, and they broadcast a ping every few seconds for up to half a year on a single button battery.
 

graywoulf

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Orange reflective tape seems to be the way to go. Wish I had done that :)
As a former sign graphics designer, I have to say that most any color of reflective vinyl will show a white reflection when hit by white light. I have black reflective vinyl that reflects sort of a yellowish color but all others show as white. Now that I have said that, I think I have some royal blue reflective vinyl somewhere. :D
 

yeoldesparky

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As a former sign graphics designer, I have to say that most any color of reflective vinyl will show a white reflection when hit by white light. I have black reflective vinyl that reflects sort of a yellowish color but all others show as white. Now that I have said that, I think I have some royal blue reflective vinyl somewhere. :D
I was thinking something like this. Same tech as in traffic signs.

91UNPWCahZL._AC_UL320_SR244,320_.jpg
 

graywoulf

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Absolutely! That is the good stuff. Much better visibility than regular reflective sign vinyl and much more expensive too. But if you have access to this vinyl then I would say go for it. Besides that, it looks cool with the honeycomb pattern.
 

yeoldesparky

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Decided to do another search for the Spark, and found it, undamaged :)

As I had guessed, it had ended up upside down in a thicket. I spotted it due to the sun glinting off of the 4 connection points on the battery. It was around 50m away from the RTH point, which was much further than expected.

It's probably a good idea for anyone that flies over forest to add some reflective tape, as I intend to do. Here's how it was hiding. It's close to the center.
 

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