Antenna on the top?

[Photo]

Hi, why does some drones have an antenna on the top? Seems that it*s more "expensive" drones...
Is it a GPS antenna for safer GPS signal or what? If so, why doesn't the H has one? I guess that an antenna on top doesn't have anything to do with a signal to and from the ground?

 

[Dr Delta]

Hi, why does some drones have an antenna on the top? Seems that it*s more "expensive" drones...
Is it a GPS antenna for safer GPS signal or what? If so, why doesn't the H has one? I guess that an antenna on top doesn't have anything to do with a signal to and from the ground?
View attachment 5552

That is a High-Resolution GPS antenna.

 

[Photo]

That is a High-Resolution GPS antenna.

Thanx, high res for GPS? Why doesn't the H has one? Cost reason? What does high res for GPS mean?

 

[Dr Delta]

High resolution GPS antenna, yes. That combines with a state-of-the-art GPS unit which has a much smaller error margin then the GPS used in the Typhoon H and for instance tablets and smartphones.
High res gps is also used in aviation and in engeneering like building roads etcetera, working with margins of centimeters/millimeters instead of meters/10's of meters like the more cheapo gps's.

Our H has a simple GPS module, mainly because of costs and also space inside the hull. Besides that is our H designed as a camera-platform, so the use of GPS is relatively subservient. The general purpose of the drones with high resolution GPS is also in more industrial fields, like inspection, mapping etcetera. The quality standards are quite different.

 

[Photo]

High resolution GPS antenna, yes. That combines with a state-of-the-art GPS unit which has a much smaller error margin then the GPS used in the Typhoon H and for instance tablets and smartphones.
High res gps is also used in aviation and in engeneering like building roads etcetera, working with margins of centimeters/millimeters instead of meters/10's of meters like the more cheapo gps's.

Our H has a simple GPS module, mainly because of costs and also space inside the hull. Besides that is our H designed as a camera-platform, so the use of GPS is relatively subservient. The general purpose of the drones with high resolution GPS is also in more industrial fields, like inspection, mapping etcetera. The quality standards are quite different.

Dr Delta! Thanx alot, now I know more than yeasterday! Lots of skilled people here...

 

[Steve Carr]

To add to that, the GPS antenna on the H is on the top but under the shell. The antenna for video transmission is inside the camera and there are two more for telemetry and control located by each of the landing gear struts.

 

[PatR]

High resolution? Who and what defined that. Perhaps we could see the published design specs from the GPS manufacturer. The H used a Ublox system, which is considered high quality for a hobby grade unit. The specs for the Ublox system have previously been published in this forum.

 

[Typhoon Charlie]

What PatR said.

Typhoon H GPS Specifications

 

[Dr Delta]

.... for a hobby grade unit.... yep. no high defintition unit.

Well.... exactly what tried to explain in very plain language, there are zillions of differences in cost/use/dimension GPS systems (and antennae). Please ask forum-newbie Mr Photo what drone it is @picture. I do not know and I do not care much. Just wanted to answer a fair newbie-question in an illustrative newbie-way.

As a professional pilot I know there are several systems that come with their cost (in money and in space/weight).
I am quite content but not at all impressed with/by the GPS functionality in the Typhoon H (that I have.... issued feb 2017). Looking @telemetry I (my GPS/Typhoon) am shooting from here to there and nowhere. Normally I take off way underground or @ altitudes that are unknown in the Netherlands (GPS readings, cause the altimeter does not know yet).
The used algorithms for navigation level these readings to servicable values, which is great. I will never deny the coolness of the H, I still am quite content with the drone and its possibillities.

Sorry Pat I kind of love you for your very useful postings and your patience every now and then. Hats off. Your contributions and good humor to this forum were a large factor in deciding for the H instead of other drones.
I have come to slightly different opinion in the last few months (since I have a H myself that is). I feel 'discussions' to have sharpened and are of less importance (seems people do not read manuals nor good willing posts) lately. This is a global issue, as a sextagenaire (like you are) I know these mechanisms.
Never mind, if my postings are just an annoying step to sublime your insights (which I esteem greatly) I'll stop posting or answering any post as of now, not wanting to step on any toes. Maybe I'll quit this forum anyhow.


Good luck and nice flights.....!

 

[Dr Delta]

What PatR said.

Typhoon H GPS Specifications

Real good for a consumer's photo platform, yes.

Nevertheless........


Cheers!

 

[PatR]

My point was in reference to the "high resolution" description. No single GPS antenna can provide any greater resolution than the signal it is being sent. To generate greater resolution requires multiple antennas separated by several meters and a complex computer program, something I've been working with for years. A few antennas only a couple inches apart don't make it happen.

 

[RiverRunner]

The antenna in the photo looks like an old NAZA GPS one, nothing special about it. In fact it is probably not as good as newer ones that also receive GLONASS. The antenna is mounted high up to avoid interference from the other electronics in the multirotor. It likely also included the compass which is sensitive to electromagnetic interference. I have purchased cheaper Chinese copies which work better than the DJI NAZA GPS antenna.

 

[Typhoon Charlie]

And that is one of the weaknesses of the H. Mounting the GPS receiver and compass so close to the electronics and battery.

 

[Photo]

.... for a hobby grade unit.... yep. no high defintition unit.

Well.... exactly what tried to explain in very plain language, there are zillions of differences in cost/use/dimension GPS systems (and antennae). Please ask forum-newbie Mr Photo what drone it is @picture. I do not know and I do not care much. Just wanted to answer a fair newbie-question in an illustrative newbie-way.

As a professional pilot I know there are several systems that come with their cost (in money and in space/weight).
I am quite content but not at all impressed with/by the GPS functionality in the Typhoon H (that I have.... issued feb 2017). Looking @telemetry I (my GPS/Typhoon) am shooting from here to there and nowhere. Normally I take off way underground or @ altitudes that are unknown in the Netherlands (GPS readings, cause the altimeter does not know yet).
The used algorithms for navigation level these readings to servicable values, which is great. I will never deny the coolness of the H, I still am quite content with the drone and its possibillities.

Sorry Pat I kind of love you for your very useful postings and your patience every now and then. Hats off. Your contributions and good humor to this forum were a large factor in deciding for the H instead of other drones.
I have come to slightly different opinion in the last few months (since I have a H myself that is). I feel 'discussions' to have sharpened and are of less importance (seems people do not read manuals nor good willing posts) lately. This is a global issue, as a sextagenaire (like you are) I know these mechanisms.
Never mind, if my postings are just an annoying step to sublime your insights (which I esteem greatly) I'll stop posting or answering any post as of now, not wanting to step on any toes. Maybe I'll quit this forum anyhow.


Good luck and nice flights.....!

Hi Dr Delta, "Mr" Photo here. I don't know what drone it is I just took a pic from internet to show a sample of GPS antenna on the top.

 

[RiverRunner]

And that is one of the weaknesses of the H. Mounting the GPS receiver and compass so close to the electronics and battery.

Phantoms have always had the GPS antenna mounted inside with a bit of shielding between it and the other electronics. They have the compass on the landing gear leg which can cause as many problems as it tries to avoid. Not sure where the compass is mounted on the H.
Edit: the compass for the Typhoon H is mounted on the GPS board. The GPS for the Typhoon H also receives GLONASS. It is shielded from the other electronics and mounted at the opposite end from the main power connections.

 

[FlushVision]

And that is one of the weaknesses of the H. Mounting the GPS receiver and compass so close to the electronics and battery.

I recall that the Phantom 2 Vision plus had a similar issue regarding the GPS receiver being mounted too close to the electronics. All that separated it from the electronics was a thin layer of insulation and, certainly, before they started shipping the V3 model, users had issues with connecting enough stable satellites for flight.

Fortunately, a third party supplier came up with a solution that involved the user first moving a wire to a position under this insulation and installing their extra insulation pad.

Users who did this, including me, on average were able to lock on to two extra satellites more than they could expect without the modification.

So, certainly, this is not a weakness unique to the H. Others have had issues to do with the proximity of the GPS module too.

 

[PatR]

For the record, my best guess has the pictured multirotor a DJI s1000, which could be equipped with a Naza, Wookong, or A2 FC. All three use essentially the same GPS antenna.

Those that build their own systems know the Ublox GPS antenna can be mounted on a pedestal and provide better function than what is provided where it's located on the H. A design improvement would incorporate and elevated antenna. Also for the record, I'm another that finds the H GPS accuracy to be less than it could be.

 

[PatR]

Photo,

After all the above I suppose the answer to your original question would be "because they were smarter than Yuneec".

It's a fact of life a GPS antenna can be significantly impacted by magnetic fields generated by power supply wires and ESC's. Home builders have been aware of this for a long time and positioned antennas and wiring as far apart as possible. There are installations where copper foil has been used to shield the bottom of GPS antennas from other electrical components. On the discontinued Yuneec/Blade Chroma, Yuneec used a pop up GPS antenna. For some reason, most likely associated with cost of production, Yuneec elected to stuff the antenna in about the worst place I can think of to have one.

I don't believe the altitude reporting issues that have been mentioned are related to the GPS though. My money would go to lack of protection at the baro altimeter from impacting wind influences. They are extremely sensitive to pressure changes and relative wind is a well known influence. Believe it or not, so is direct sun light.

 

[Photo]

Photo,

After all the above I suppose the answer to your original question would be "because they were smarter than Yuneec".

It's a fact of life a GPS antenna can be significantly impacted by magnetic fields generated by power supply wires and ESC's. Home builders have been aware of this for a long time and positioned antennas and wiring as far apart as possible. There are installations where copper foil has been used to shield the bottom of GPS antennas from other electrical components. On the discontinued Yuneec/Blade Chroma, Yuneec used a pop up GPS antenna. For some reason, most likely associated with cost of production, Yuneec elected to stuff the antenna in about the worst place I can think of to have one.

I don't believe the altitude reporting issues that have been mentioned are related to the GPS though. My money would go to lack of protection at the baro altimeter from impacting wind influences. They are extremely sensitive to pressure changes and relative wind is a well known influence. Believe it or not, so is direct sun light.

Hi PatR , I "love" people who knows what they are talking about, as you do! Thanx! As people here seems to do all kind of modifications, why not try to put the GPS antenna outside even on a H?
Is it cause the GPS module is to cheap = no reason to do that = it wouldn't help.

 

[mcbutler]

.... for a hobby grade unit.... yep. no high defintition unit.

Well.... exactly what tried to explain in very plain language, there are zillions of differences in cost/use/dimension GPS systems (and antennae). Please ask forum-newbie Mr Photo what drone it is @picture. I do not know and I do not care much. Just wanted to answer a fair newbie-question in an illustrative newbie-way.

As a professional pilot I know there are several systems that come with their cost (in money and in space/weight).
I am quite content but not at all impressed with/by the GPS functionality in the Typhoon H (that I have.... issued feb 2017). Looking @telemetry I (my GPS/Typhoon) am shooting from here to there and nowhere. Normally I take off way underground or @ altitudes that are unknown in the Netherlands (GPS readings, cause the altimeter does not know yet).
The used algorithms for navigation level these readings to servicable values, which is great. I will never deny the coolness of the H, I still am quite content with the drone and its possibillities.

Sorry Pat I kind of love you for your very useful postings and your patience every now and then. Hats off. Your contributions and good humor to this forum were a large factor in deciding for the H instead of other drones.
I have come to slightly different opinion in the last few months (since I have a H myself that is). I feel 'discussions' to have sharpened and are of less importance (seems people do not read manuals nor good willing posts) lately. This is a global issue, as a sextagenaire (like you are) I know these mechanisms.
Never mind, if my postings are just an annoying step to sublime your insights (which I esteem greatly) I'll stop posting or answering any post as of now, not wanting to step on any toes. Maybe I'll quit this forum anyhow.


Good luck and nice flights.....!

Dont go Doc, I enjoy your informative posts