Lost signal after landing in remote spot

[Free]

tried landing my p3a in remote spot and it lost communication with aircraft. I was doing this about 3000 feet away but within sight, was watching it through a spotting scope. No camera or commands could be sent or received. I thought that it had crashed but when I got to it it was just sitting there powered up and motors, gimbal and camera were bead. I picked it up and brought it back and this time I landed it only about 500 feet away and after it landed my signal was very week. It's like the ground blocks the signal even though it's in line of sight. Any body have this happen before and what could I do to correct it

 

[maxwell smart]

The antennas are in the legs. So keep up in the air. When you land the antennas are at the lowest point and don't receive well there.

 

[WetDog]

Line of sight is exactly that. Scrunch down on the grass at antenna height (like maxwell points out, the antennas are in the legs) and see how much of a 'line of sight' you actually have. A six inch mound of dirt or even a bunch of grass / scrub** will attenuate the RF signals nicely.

** Vegetation typically consists largely of water. Water absorbs 2.4 GHz signals like a sponge (sorry). So do buildings, trees, clouds. Metal things reflect signals. With all of this going on it's amazing we can connect to the the birds at all.

 

[4wd]

You could land in a distant known safe place for example a friends house provided you have loss of signal action set to land not RTH.
If not done, in the case above it wouldn't have surprised me if it lost signal before touching down and shot up again to RTH.

 

[Free]

There was nothing restricting the line of sight not even a blade of grass. I was on a hill about 20 feet high overlooking a perfectly flat field with no vegetation at all. The field is barren waiting to be planted. Is there a different antenna either on drone or transmitter that would help

 

[Multicoptertec]

How were your antennas oriented on the RC?

 

[RocketBrew]

 

[Free]

Straight up. I was sitting at a table and had 100% signal strength until it touched down then nothing and go app said disconnected. I watched it land perfectly through my spotting scope

 

[WetDog]

Straight up. I was sitting at a table and had 100% signal strength until it touched down then nothing and go app said disconnected. I watched it land perfectly through my spotting scope

That isn't normal behavior. It should land, turn off the motor (sensor on the legs) and happily sit there. From 3000 feet I can envision some path distortion from ground - you're pretty far away. 500 feet, not so much (I assume you are still actually ABOVE the level of the P3 and essentially looking down it).

That said, radio waves can behave oddly at low angles and close to the ground. An experiment would be to put a set of windsurfer antenna reflectors (free to cheap, look it up) and see what you get. That focuses the beam in a somewhat more rectilinear fashion.

 

[Free]

How much do the reflectors help in normal flight. I think I will try one and find out if it helps and if not I may go the directional antenna way like the Terminator

 

[WetDog]

If your even thinking about boosting signal with an antenna mod, you should start out with a windsurfer design. You can make them yourself out of aluminum foil and cardboard, you can buy ones for around $20-$30. Like all antenna mods, they help but not always and not as much as one would perhaps want. In your specific case it seems like you are not getting enough signal at certain times. Certainly focusing the beam stands a good chance of helping. This assumes that there is nothing wrong with your RC / P3 but if you can make it to 3000 feet in a stock configuration, that sounds reasonable.

Here is some light reading....

http://www.hindawi.com/journals/ijdsn/2012/969712/