A few years ago there was common to build a so-called ground station (GS), that usually consists of the following: receiver, antenna(s), monitor(s), battery pack, all integrated into a small unit, generally a suitcase. As the technology went ahead, receivers got smaller and many video goggles were developed, so we got into a point when there is no need for the GS anymore.
Today’s best solution is to buy video googles that has a modular system, so the receivers are interchangeable. The best googles even have an inbuilt DVR (digital video recorder) unit, and a headtracker as well. The antenna mounted on the goggles, especially for 5.8G is very small and handy.
So basically, we can divide the ground unit solutions for mobile and static ones. The mobile solution allows the user to pack/unpack it fast, or even move with it freely (no cabling), while the static solution as the name indicates is mounted in one place and packing/unpacking is time consuming.
Every ground unit, however, needs the following basic components:
- powering (battery or battery packs)
- display unit (monitor, LCD, goggles)
There are some more sophisticated solutions where one needs precise and stable control all the time. In these cases, a technology called “diversity” is used. It can be achieved either by multiplying the receiver modules (static), or by using an antenna tracker module (dynamic), that is able to track the multicopter in the air and automatically position the antenna to get the best signal.
This technique is getting out of use nowadays, mostly because of the fact that the antennas are getting better and even the directional ones are developing to have wider angles, so at moderate ranges tracking is no more needed.
Regarding the display units, many votes for LCD displays and many for goggles. It is the personal preference for each user. Both solutions have advantages and disadvantages as well.
- – reflections on sunny days
- – display brightness
- + resolution (details)
- – cabling
- – powering
- – size (large displays)
- – blue screen (many LCD-s can not handle static)
- + no reflections
- + no cabling
- – fogging
- – discomfort (for some)
- – optical incompatibility (eye distance, diopters,…)
- – weight (some goggles may be heavy)
- + no “blue screen”
One of the biggest problem when using LCD displays is the lack of week signal handling (“blue screen” effect). That means, if the signal is too weak, the LCD unit switches to a static screen, instead of showing at least some noisy picture. This way the flyer gets copletely blind, instead of seeing a garbaged, distorted picture, upon which he could still fly.
Of course, loosing the picture in many cases means loosing the control and crash.