GPS Elevation Mask.What is the minimum you use with UAV Forecast?

jcommstudios · Sep 14, 2019

Typhoon H480..GPS Elevation Mask what is the minimum you use from UAV Forecast?

PatR · Sep 14, 2019

I don’t know that’s user adjustable with an H but 8 sats would be my minimum number.

To be completely honest, I don’t care what UAV Forecast has to say about that or the KP index as the ST-16 displays what I need to know where I am flying, not some generalized info encompassing several continents.

There’s a term; paralysis through analysis, that will quickly hamstring people that get too wrapped up in data of questionable usefulness.

Mrgs1 · Sep 15, 2019

I keep it on 15. It is adjustable, but the whole App is only a guide to me personally, local conditions can vary dramatically, and it can be way out.

FlushVision · Sep 15, 2019

Depends on where I'm planning to have a fly. Open countryside far enough away from any significant hills or trees or if my take-off point is on higher ground than that surrounding me I set it to 5. If on lower ground or with trees fairly close by then it's 10. In a valley or next to a high hill, or if it's an urban PfCO flight it's 15

So, it's where I am and what is around me that determines the settings I choose.

jlading · Sep 15, 2019

PatR said:
I don’t know that’s user adjustable with an H but 8 sats would be my minimum number.

To be completely honest, I don’t care what UAV Forecast has to say about that or the KP index as the ST-16 displays what I need to know where I am flying, not some generalized info encompassing several continents.

There’s a term; paralysis through analysis, that will quickly hamstring people that get too wrapped up in data of questionable usefulness.

PatR, you bring up a very good point. "Paralysis through analysis". I suffer from this myself. After reading some of the posts here and Facebook, I get a little queazy about putting my birds up in the air. I gotta stop that

.

jcommstudios · Sep 15, 2019

FlushVision said:
Depends on where I'm planning to have a fly. Open countryside far enough away from any significant hills or trees or if my take-off point is on higher ground than that surrounding me I set it to 5. If on lower ground or with trees fairly close by then it's 10. In a valley or next to a high hill, or if it's an urban PfCO flight it's 15

So, it's where I am and what is around me that determines the settings I choose.

@FlushVision Thanks! it appears you understood the question. I use UAV Forecast as a somewhat informal guide to what the conditions are and generally keep the indicator at 15 as a basis. I read that 5 is acceptable in flatland areas which adds a bunch of Sats. First day, in a while, that it is not hotter than **** here in the California Central Valley and haven't flown the H in a while. I've been shooting with the EVO and the H480 needs some flight time. I noticed the Sats start falling off around 1:00 PM at a setting of 15. At 5 it indicates there are plenty all day. Going to shoot out in the Delta which is in "The Big Valley" and very flat for miles. Thanks for confirming my thoughts! Jim

PatR · Sep 15, 2019

We need to know more about how the U-Blox module is set up as many GPS units intentionally ignore GPS data from satellites located within 10* of the horizon as they can provide unreliable signal due to curvature of the earth.

Primary causes of GPS masking that are of concern to short range multirotors are structures and foliage. We (multirotor operators) flying LOS just don’t put our aircraft out far enough for curvature of the earth to be a problem.

Because structures and foliage are always relative to the flight location I don’t understand why UAV forecast considers it an issue. For those flying long range, and by long range I mean tens of miles or more, it’s certainly a concern, but not for range limited multirotors. We only need 6-8 sats for reasonably good position data. For us C2 signal masking is more of an issue.

PatR · Sep 15, 2019

Where are you at in the Valley? I’m just above it in Calaveras County.

Mrgs1 · Sep 15, 2019

FlushVision said:
Depends on where I'm planning to have a fly. Open countryside far enough away from any significant hills or trees or if my take-off point is on higher ground than that surrounding me I set it to 5. If on lower ground or with trees fairly close by then it's 10. In a valley or next to a high hill, or if it's an urban PfCO flight it's 15

So, it's where I am and what is around me that determines the settings I choose.

Do you feel in UK the lower setting is beneficial? Do we really have any areas possibly Scotland I suppose where using higher Sat's would help, just curious.

FlushVision · Sep 15, 2019

Mrgs1 said:
Do you feel in UK the lower setting is beneficial? Do we really have any areas possibly Scotland I suppose where using higher Sat's would help, just curious.

If flying in an urban area (legal under PfCO Exemptions) a high setting is helpful to mitigate for surrounding structures since those buildings are going to shadow GPS particularly during take-off and landing phases. Same with hills. Living next to the Pennines I have my fair share of them things. A lower setting is only of any benefit when the take-off point is on higher ground...taking off from the top of those said hills.

At this point a take a nod to what @PatR says that curvature of the Earth not being an issue to LOS flights but I still see nearby structures and hills as a concern in regard to Mask. For example, I also fly an elderly P2V+ (thinking of retiring it though) which will only 'see' the American GPS constellation. However, it requires to 'see' at least 6 useful satellites for a GPS assisted flight. Many is the time I've taken off from a place where mask has been an issue and finished up doing the flight manually. When flying that P2V+, then, I've always found it helpful before setting out to consult resources for current satellites count with a higher mask setting than I would with my TH and choose my take off point with more care. Indeed, if the number of sats predicted 'seen' is on the low side I may choose to use my TH instead since it can see multiple constellations...to date I've never had an issue picking satellites up when using my TH except when taking off next to a building. I can't say that for my P2V+...I learned quickly how to fly manually with that thing.

Mrgs1 · Sep 15, 2019

FlushVision said:
If flying in an urban area (legal under PfCO Exemptions) a high setting is helpful to mitigate for surrounding structures since those buildings are going to mask GPS particularly during take-off and landing phases. Same with hills. Living next to the Pennines I have my fair share of them things. A lower setting is only of any benefit when the take-off point is on higher ground...taking off from the top of those said hills.

At this point a take a nod to what @PatR says that curvature of the Earth not being an issue to LOS flights but I still see nearby structures and hills as a concern in regard to Mask. For example, I also fly an elderly P2V+ (thinking of retiring it though) which will only 'see' the American GPS constellation. However, it requires to 'see' at least 6 useful satellites for a GPS assisted flight. Many is the time I've taken off from a place where mask has been an issue and finished up doing the flight manually. When flying that P2V+, then, I've always found it helpful before setting out to consult resources for current satellites count with a higher mask setting than I would with my TH and choose my take off point with more care. Indeed, if the number of sats predicted 'seen' is on the low side I may choose to use my TH instead since it can see multiple constellations...to date I've never had an issue picking satellites up when using my TH except when taking off next to a building. I can't say that for my P2V+...I learned quickly how to fly manually with that thing.

I can see the benefits for some areas, I suppose for now I fly possibly restricting myself by not flying any urban or areas as such, just hilltops of the Cotswold's and open areas.

FlushVision · Sep 15, 2019

Mrgs1 said:
I can see the benefits for some areas, I suppose for now I fly possibly restricting myself by not flying any urban or areas as such, just hilltops of the Cotswold's and open areas.

I did a commercial job at a church a few weeks ago (in an urban area incidentally). I had previously tried to do that job using my P2V+ but had to abandon the job because of the GPS 'shadow' from the church. I finished up doing the job using my TH but even that was iffy due to the shadow. It was a close up inspection of high gutters but the church tower was giving me grief.

I won't fly urban unless someone pays me to do it and I have a good clearance from building not under my control. I took off from the graveyard which gave good clearance but that church tower loomed above me.

jcommstudios · Sep 15, 2019

PatR said:
Where are you at in the Valley? I’m just above it in Calaveras County.

@PatR I'm in Stockton. I have had a cabin in Murphys, on the creek, for years (well my ex-wife does now..lol) I'm up that way all the time. You should let me know where you are and perhaps we can meet up and shoot some footage some time. Lots of great places to shoot up there. All the best, Jim

PatR · Sep 15, 2019

We’re close. Valley Springs.

jcommstudios · Sep 15, 2019

PatR said:
We’re close. Valley Springs.

@PatR I'm very familiar with Valley Springs. Just about a 40 minute drive from my house which is off the Miracle Mile in Tuxedo Park in Stockton.

PatR · Sep 15, 2019

We should get together one of these days. Too darn hot to do any flying right now. Spring time up this way can be pretty, but we have to steer clear of the lakes. All the reservoirs and associated water shed are DHS no fly areas.

jcommstudios · Sep 15, 2019

PatR said:
We should get together one of these days. Too darn hot to do any flying right now. Spring time up this way can be pretty, but we have to steer clear of the lakes. All the reservoirs and associated water shed are DHS no fly areas.

@PatR Sounds good to me. Yes it has been an extremely hot summer. Valley Springs is about the same as here temp wise. I'd be up for a trip and yep we can stay clear of the lakes and water shed. Lots of cool stuff to shoot other than lakes in the area if you look for it. Once the colors change, which should be soon, it is beautiful in the foothills. I would imagine Pardee is considered watershed. Always amazed me that they will allow motor boats but no swimming. I was up there fishing a couple of months ago and it was at 101% of capacity and the spillway was dumping like crazy.
Lets stay in touch and we will take a day, some time soon, and find some interesting areas to shoot.

PatR · Sep 16, 2019

Can do.

Pardee is part of the Bay Area’s drinking water supply. It’s ok for them to come up here and foul our water supply with their bodies and waste but they won’t tolerate us doing the same to theirs[emoji6]

They also have an interesting outlook about drones. They flat prohibit drone operations but are fully aware some of their low level employees are filming the lake and spillway using drones for posting on YouTube and won’t do anything about it. Had a conversation with their management about all that. Learned there is a double standard where regulatory enforcement is concerned.