Radar indicator, and a few other questions

Cometstorm · Jun 30, 2017

Ok, newbie stilll trying to get a handle on a few things.

The circular radar image. Why does it exists?

I mean, in the somewhat limited flying I've done so far, I always use the Map indicator. It shows RC point, AC point, and home point, AC orientation, and even flight path (for an easy return home) so why the need for the radar? What am I missing?

Is this a case that if MAPS should fail, then RADAR is a fall-back?

Another question, I see a lot of posts about losing GPS acquisition. Thus, the need to learn how to fly in ATTI.

I read so much about loss of GPS, that it worries me (perhaps too much?).

Does it occur mainly around mountains, canyons, high buildings, vastly uneven terrain and such?

Out here in the USA midwest flatlands, everything is pretty even for the most part. Should my GPS worries be reduced?

Lastly, if one loses GPS and imaging/telemetry.... and the bird is beyond LOS. I guess your pretty much cooked and have to go find it? I assume in that case even RTH is a gonner?

Also, am I to assume ATTI is only good for LOS? No good for beyond LOS?

microlinux · Jun 30, 2017

GPS satellites are above you. The path between you and the satellites has to be unobstructed. RTH does rely on GPS.

Meta4 · Jun 30, 2017

Cometstorm said:
The circular radar image. Why does it exists?
I mean, in the somewhat limited flying I've done so far, I always use the Map indicator. It shows RC point, AC point, and home point, AC orientation, and even flight path (for an easy return home) so why the need for the radar? What am I missing?
Is this a case that if MAPS should fail, then RADAR is a fall-back?

The radar display is an alternative to the map display and I find it more useful in my flying.
Here it's showing me that my Phantom is out directly in front of me and shows it is pointing slightly to the right.

Cometstorm said:
Another question, I see a lot of posts about losing GPS acquisition. Thus, the need to learn how to fly in ATTI.
I read so much about loss of GPS, that it worries me (perhaps too much?).
Does it occur mainly around mountains, canyons, high buildings, vastly uneven terrain and such?
Out here in the USA midwest flatlands, everything is pretty even for the most part. Should my GPS worries be reduced?

The fear of losing GPS is overdone by some.
You won't lose GPS unless:

You have a compass error (and with proper habits you'll never have a compass error)
You fly into a narrow canyon or under cover that would block the Phantom's sky view.
You have a very rare GPS equipment failure

After three years flying, I haven't encountered any of those.

Cometstorm said:
Lastly, if one loses GPS and imaging/telemetry.... and the bird is beyond LOS. I guess your pretty much cooked and have to go find it? I assume in that case even RTH is a gonner?
Also, am I to assume ATTI is only good for LOS? No good for beyond LOS?

The hypothetical scenario is a bit extreme. I don't think you'd find yourself in that situation, especially losing GPS.
If your Phantom is way out and you lose signal it will initiate RTH and come home - provided you have sufficient battery, the wind isn't too strong and there are no tall obstacles to block its path.
Atti will work whether you are beyond visual range or not.
Whether you want to use it when you can't see the Phantom is another matter.

Tazz5 · Jun 30, 2017

ATTI is nothing to be scared of.
On a calm day with little wind take your bird up above everything around you and switch it to ATTI mode and don't touch anything. It will drift with the wind. If it's drifting away from you turn it so it's facing away from you and pull back on the right stick (reverse). Play with it a little, get the feel of it. You can always put it back in GPS mode if things start moving too fast for you, just make sure that you're flying higher than anything around you.

ATTI does not rely on LOS, your bird is still connected to your controller. Remember that radar thing? Turn so your RC is facing the AC, in the radar, for better signal strength. You'll be able to see where your AC is relative to you and what direction it's pointing in.

aburkefl · Jul 1, 2017

It might be my imagination, but...

A couple of times, I've gone through my checklist, getting ready to fly, and noticed that the radar data looks like it's "out of sync." That is, my Phantom is actually pointing north (sitting on my "airport" which is a 3' square piece of plywood!) but the radar icon indicates it's pointing well towards the east or west. I calibrated the compass and then the radar showed the proper orientation.

As I said, that may have been my imagination, but that's what it looked like to me.

Art - N4PJ
Leesburg, FL

Meta4 · Jul 1, 2017

aburkefl said:
I calibrated the compass and then the radar showed the proper orientation.

If the plane icon is pointing in the wrong direction, the thing to do is to calibrate the compass ... in your tablet (not the Phantom).

Cometstorm · Jul 1, 2017

Thanks guys,

Newbies have a lot to chew on.

Sometimes over and over and OVER until it finally clicks and sticks!

Cometstorm · Jul 1, 2017

Ok, I think I'm starting to "get"
the radar use.

Maps will show you general. AC, RC, home point data relative to each other.

But Radar will give you signal direction as it is dynamic with the RC pointing (antenna direction) relative to the AC.

So, for a beginner Radar user, I guess it would be best to keep the AC icon nearly straight up on the radar circle, and rotate your RC laterally to keep it that way as the AC flight path changes. At least if signal strength was your biggest consideration?

Particularly so if your in a generally new flight location where ground Mapping may be unfamiliar?

In other words, if I'm in a area that I'm familiar with ground data (say, my house and neighborhood) then Maps might be better if I'm not concerned as much with signal strength due to closer AC/RC positioning...

Would all that be pretty correct?

Meta4 · Jul 1, 2017

Cometstorm said:
But Radar will give you signal direction as it is dynamic with the RC pointing (antenna direction) relative to the AC.
So, for a beginner Radar user, I guess it would be best to keep the AC icon nearly straight up on the radar circle, and rotate your RC laterally to keep it that way as the AC flight path changes. At least if signal strength was your biggest consideration?

Particularly so if your in a generally new flight location where ground Mapping may be unfamiliar?
In other words, if I'm in a area that I'm familiar with ground data (say, my house and neighborhood) then Maps might be better if I'm not concerned as much with signal strength due to closer AC/RC positioning...

Would all that be pretty correct?

That's about right.
One of the most important points is that you can see the orientation of your Phantom and know which way it is pointing rather than wondering.
That makes it easy to turn it the desired direction rather than flying all over the sky trying to get it right.
Here's another example:

For my flying, the radar and telemetry shows me what I need to know. I've probably only used the map 2 or 3 times in 3 years.

DanMan32 · Jul 1, 2017

Note that top of the radar is relative to the direction you are facing, assuming your tablet has a compass. If yours doesn't, top is always north.
Radar also shows AC horizon tilt and coarse distance from you.
DJI has a useful training video on the radar and telemetry. It was based on P3 but applicable to later models for the most part.
If you have an Inspire, it will also show camera direction. That's what the other triangle is for but fixed for the rest of us.

As for RTH due to signal loss, you can lose video and telemetry signal from AC to you but AC still receiving RC signal. That's happened to me a couple times, 1st time I thought I lost my P3 after waiting 4 minutes for RTH. It returned instead due to low battery where on its way back I regained video and telemetry.

Cometstorm · Jul 2, 2017

Thanks a bunch guys...

I'll have to get my P3A out today, and see if I can configure squares (including the green one) that Meta posted.

crash1sttime · Jul 2, 2017

aburkefl said:
It might be my imagination, but...

A couple of times, I've gone through my checklist, getting ready to fly, and noticed that the radar data looks like it's "out of sync." That is, my Phantom is actually pointing north (sitting on my "airport" which is a 3' square piece of plywood!) but the radar icon indicates it's pointing well towards the east or west. I calibrated the compass and then the radar showed the proper orientation.

As I said, that may have been my imagination, but that's what it looked like to me.

Art - N4PJ
Leesburg, FL

you are not mistaken, it does sometimes happen, I first noticed it when flying my Phantom 2 Vision , the fix was to shut everything down and restart, this usually fixed it. its happened a couple of times with my P3A as well.

aburkefl · Jul 2, 2017

Meta4 said:
If the plane icon is pointing in the wrong direction, the thing to do is to calibrate the compass ... in your tablet (not the Phantom).

I defer to your opinion as (1) didn't have any idea my tablet might have a compass and (2) calibrating the compass in my Phantom "straightened up" the appearing to be out of sync icon - I have *never* calibrated a compass in my tablet.

Art - N4PJ
Leesburg, FL

Meta4 · Jul 2, 2017

Cometstorm said:
Thanks a bunch guys...
I'll have to get my P3A out today, and see if I can configure squares (including the green one) that Meta posted.

Don't worry about the green square.
It's a focus point for the P4 pro and the P3 series don't have it.

Numone · Jul 3, 2017

I use the radar display a huge amount. In fact, it is this single feature that tends to drive me toward a launch using GO rather than Litchi. It's invaluable to keep the TX aligned with the AC, as well as the AC orientation. Love it.

Numone · Jul 3, 2017

aburkefl said:
I defer to your opinion as (1) didn't have any idea my tablet might have a compass and (2) calibrating the compass in my Phantom "straightened up" the appearing to be out of sync icon - I have *never* calibrated a compass in my tablet.

Art - N4PJ
Leesburg, FL

My iPad compass calibration often comes up when I launch GO or Litchi.

aburkefl · Jul 3, 2017

Numone said:
My iPad compass calibration often comes up when I launch GO or Litchi.

Okay - I guess what you're referring to is when you power up the app and a circle appears on the device and you have to "roll" the ball around the circle? Yes, I have seen that - but only once every blue moon LOL. I have no idea how you would call that up on purpose. I think when I saw it, I thought it was involving the controller - never thought about my tablet.

Most of my flying the last few months has been with Litchi - on my iPad. The iOS version doesn't have the radar icon. It can't calibrate the IMU either. As far as I can tell, you *must* run DJI GO to utilize the calibration function for the IMU.

Art - N4PJ
Leesburg, FL

Numone · Jul 3, 2017

aburkefl said:
Okay - I guess what you're referring to is when you power up the app and a circle appears on the device and you have to "roll" the ball around the circle? Yes, I have seen that - but only once every blue moon LOL. I have no idea how you would call that up on purpose. I think when I saw it, I thought it was involving the controller - never thought about my tablet.

Most of my flying the last few months has been with Litchi - on my iPad. The iOS version doesn't have the radar icon. It can't calibrate the IMU either. As far as I can tell, you *must* run DJI GO to utilize the calibration function for the IMU.

Art - N4PJ
Leesburg, FL

Correct. There doesn't appear to be a set number of starts, its random. The old compass app itself is no longer included in the iPad iOS, hence why you can't find it.
Yeah, as per my other post, I really like Litchi but the absence of the Radar makes me use GO far more often.