Dogpilot
Well-Known Member
You need to realize that the GPS signal is very weak, not a high powered output at all. Easily masked by your roof, cement, trees lots of snow, thick with precipitation clouds and so on. One other item is if you have not used your drone in a while, the GPS has to get one other periodic bit of info, the Almanac Data. This is an update on orbital parameters and timing data the internal computer needs to produce a fix. It has to download it from the satellites. Even when I was a Midshipman on a boat, I needed the Nautical Almanac and the HO223 to digest my star shots. Without it, wasn't much I could do with a sextant. Same for the GPS computer. In aircraft, our GPS is occasionally supplemented by a ground station that is very precisely surveyed in and corrects the orbiting satellites in the local area for approaches. Same with RTK and your tying in with NTRIP networks. The network feeds in information that provides the corrections needed to give you inch capable position.
I live next to the Naval Observatory, which is the facility that uplinks all the corrections daily. The director is my hanger neighbor. We have a couple of pages in our GPS in aircraft that tell you several facts about your GPS, aside from signal strength, there is, as previously mentioned, the geometry. The system will let you know if any are out of parameter and do a prediction of where you are going to let you know if you will have approach level positioning on arrival ahead of time. Low orbit satellites, you lose signal all the time. In Borneo, which is exceptionally rugged. Very deep valleys and steep mountains. My sat phone would only work for 3 minutes at a time as the satellites shot from the now very close, due to mountains, horizon to horizon. Led to me staring at the phone and cursing frequently as the conversation abruptly cut off.
I live next to the Naval Observatory, which is the facility that uplinks all the corrections daily. The director is my hanger neighbor. We have a couple of pages in our GPS in aircraft that tell you several facts about your GPS, aside from signal strength, there is, as previously mentioned, the geometry. The system will let you know if any are out of parameter and do a prediction of where you are going to let you know if you will have approach level positioning on arrival ahead of time. Low orbit satellites, you lose signal all the time. In Borneo, which is exceptionally rugged. Very deep valleys and steep mountains. My sat phone would only work for 3 minutes at a time as the satellites shot from the now very close, due to mountains, horizon to horizon. Led to me staring at the phone and cursing frequently as the conversation abruptly cut off.
