Naïve question - WiFi is only LOS and satellites are for GPS, right?

Buel · Dec 26, 2020

Stupid question, I'm afraid (but I have to say that this is the only forum I know that doesn't all gang up on someone asking seemingly obvious questions):

After playing around with my MM, I have found that I can get around 600m in distance over the countryside with no obstructions and 800m by using the reflectors I bought from Amazon.

1. Can I just check that using wifi only works if you have clear line of sight? ie - any trees or obstacles will just stop or vastly reduce the signal strength?
2. Why is my signal so poor when I go directly up above myself and yet I hold my RC facing up?
3. Are using the satellites purely to determine GPS data such as distance, altitude, speed, etc?

Sorry if these are silly questions.

P.S. My MM2 is coming this week so hoping to get more distance?

Deleted member 103366 · Dec 26, 2020

GPS is for position information ONLY,and the calculations based on that information. Control is via the radio signal to and from the controller. I don't know if it is wifi, I just cover my derrier and say radio.
How high are you going overhead? Regarding antennae orientation, imagine a line drawn from the drone to the controller, the antennae should be perpendicular to the line and parallel to one another, like the cross bar on a cross.

Buel · Dec 26, 2020

Thanks, Don't know why I said Wifi. Odd.
Re the antennae orientation - can anyone supply an image? I have one facing forward and one facing back to me?

Deleted member 103366 · Dec 26, 2020

People keep mentioning wifi so it's probably from that. Whether the signal is 'packaged', broadcast and recieved in the same way as wifi signals I have no idea and then there is the frequency etc etc, again no idea but I think radio is a broad enough cover "to do" lol.

Perhaps you should supply a picture of your attenae orientation I can not make sense of your written descriiption. In fact, from it, I am a bit concerned something is broken.
the mini manual can be downloaded from Mavic Mini - Downloads - DJI and contains orientation diagrams on page 29

SkyeHigh · Dec 26, 2020

Buel said:
Stupid question, I'm afraid (but I have to say that this is the only forum I know that doesn't all gang up on someone asking seemingly obvious questions):

After playing around with my MM, I have found that I can get around 600m in distance over the countryside with no obstructions and 800m by using the reflectors I bought from Amazon.

1. Can I just check that using wifi only works if you have clear line of sight? ie - any trees or obstacles will just stop or vastly reduce the signal strength?
2. Why is my signal so poor when I go directly up above myself and yet I hold my RC facing up?
3. Are using the satellites purely to determine GPS data such as distance, altitude, speed, etc?

Sorry if these are silly questions.

P.S. My MM2 is coming this week so hoping to get more distance?

The Mavic Mini does use WiFi to communicate via radio between the aircraft and controller. All radio signals can be attenuated by objects such as trees, buildings etc. How much the signal is reduced depends on the radio frequency used and the density of the object the signal is trying to pass through.

To maintain a good signal the antenna should be positioned as shown in the manual. However, if you have added reflectors they must be pointed towards the aircraft at all times as the greatly reduce the spread of the transmission and reception to a relatively narrow beam. Therefore if your aircraft is overhead you will need to point the reflector directly toward the aircraft.

GPS is used by the aircraft to determine its position. Based on position data and time the flight controller can calculate speed and thereby distance travelled. Altitude is measured using a barometer but uses downward facing infra-red sensors for greater accuracy below 30-metres.

old man mavic · Dec 26, 2020

@Buel the MM is not really suitable to be flown great distances mainly because of it small size ,
and you will lose sight of it at quite close range ,the Mini 2 is better for maintaining it signal between the RC and AC, as it uses Occusync which gives a much more stable signal ,the issue is it is still difficult to see at distance ,so if you fly it to far out from where you are you will still lose sight of it ,and we all know what that means

Paci Fista · Dec 27, 2020

Re: orientation of antennas. 'Pointing towards the drone' is misleading.
These antennas transmit and receive with the FLAT side, not with the points. So the right position is almost always to have them pointing vertically, towards the ground or the sky, whilst standing facing of the drone (pointing the receiver in the direction of the drone, that is).
The ONLY exception is (indeed) when the drone is overhead. Then you flip the antennas horizontally (level with the ground) so that it beams upwards toward the drone.

Your suggestion that you would point one antenna up and the other flat is not in order. This angular position of two antennas is only correct for 3G/4G style wave reception/transmission.

Dave Maine · Dec 27, 2020

Note that gps altitude information is not used in positioning. The barometric altimeter sensor is used.

Buel · Dec 27, 2020

Paci Fista said:
Re: orientation of antennas. 'Pointing towards the drone' is misleading.
These antennas transmit and receive with the FLAT side, not with the points. So the right position is almost always to have them pointing vertically, towards the ground or the sky, whilst standing facing of the drone (pointing the receiver in the direction of the drone, that is).
The ONLY exception is (indeed) when the drone is overhead. Then you flip the antennas horizontally (level with the ground) so that it beams upwards toward the drone.

Your suggestion that you would point one antenna up and the other flat is not in order. This angular position of two antennas is only correct for 3G/4G style wave reception/transmission.

Sorry for the confusion, guys. This is wrong then?