Drone advice needed, please

I was considering paying for a ‘Drone Survey’ of a site, to supplement my conventional measurement … But a quick cost/benefit analysis suggests that buying a small drone would be a much better idea !!

Steve’s recent thread: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=179395

suggests that a 249g drone would suffice

Obviously, I would like something with the optics to do photogrammetry … but let’s keep this realistic …

Can anyone please point me to representative imagery from a low-flying, modestly priced, easily handled drone ?

I only need static nadir images from a few specific locations, and video of a general fly-around.

Grateful for any advice.

MichaelG.

There is now Regulations for where and who can fly drones which also require registration and training how much training I think depends on the size of the drone and what your going to do with it. I don’t think its complicated but it does need consideration before going out and spending money.

Register to fly a drone or model aircraft | Civil Aviation Authority (caa.co.uk)

the test is easy, have the rules and regs open while you do the test paper.

After you pass you will have to pay £10 to the Gov. you will get an OPERATOR ID and a FLYER ID, Flyer ID is foir you the flyer of the drone, the OP id is for the owner of the drone. The OP id is in the form GBR-OP-############ and should be displayed on the drone. Drones under 250grams are subject to less restictions than larger drones and can be flown just about anywhere ( subject to official no fly zones such as airports, prisons etc.

Another important must have is INSURANCE, what damage can a sub 250gram drone do?

Try telling that to the judge when you are being sued for taking someones eye out........

Basically the rules and regs have almost put paid to larger drones apart from commercial use.

the biggest impact has been on model aircraft flyers who are now subject to the same rules and regs..

ALL model aircraft are classed as drones.

they are good fun though........

How will you process the 'few' images Michael? I build drones ( fixed wing) that Surveyors use for land survey - fitted with reasonable ( 25mpxel) cameras and 50mm lenses - we fly with autopilot, a ladder track over the area taking photos that have left/right/forward overlap of 40 to 60%. We used Agisoft software to process - creating full 3D imagery, full dimensions, volumes, etc. Used a lot by local mines to determine stockpile volumes versus mined 'hole' volume, etc. Camera sensor size/pixels, lens focal length, etc all play a role in ground resolution - so not sure what you are after - We have obtained very good results - 10cm ground accuracy to 2sigma - with simple cameras Canon Powershot - pocket camera - 350grams, with a pentax fixed focus 50mm lense. FLight height above ground should be better controlled if sub 10cm ground resolution is needed...since I don't know what you need, I cannot comment!

What constitutes to be an aircraft? Are there minimum weights, size etc.

Eg: Is a paper dart an aircraft ? A chuck glider, again a 20p chuck glider sold on the beach as opposed to a competition glider which could be seriously large and heavy.

Anything over 250g requires registration. But some regulation applies to those less than 250g you need to wade through the regs.

plus you need a licence to take photos with it!

My toy drone is under 250g and takes photos but it's quite hard to fly: a few hours wasn't enough for me to reliably steer it around a course, even with no wind. Even after much practice I'm nowhere near good enough to aim the camera accurately. Transmitter range, fly time, and height are all limited. Might be good enough if Michael's needs are trivial, but the amount of effort needed to learn to fly it is off-putting.

A friend has a £600 drone which he says is easy to fly and great fun. Three or four times bigger than mine. No problem getting up to 400 feet, it's auto-stabilised, obeys orders smoothly,the transmitter range is several hundred meters, and if the control signal is lost, the drone flies itself back to the launch point and lands. It has GPS and knows where it is to within about 5 metres. He can also see what the camera is looking at. This would do the job I think, apart from processing the images. However I wouldn't spend £600 on a drone that only did a few jobs, I'd need more fun out of it. Worth checking drone prices though - they've been coming down steadily over the last few years. What my friend wanted was about £2000 when he first enquired 5 or 6 years ago. He waited!

Dave

Helium balloon (perhaps several), a long string and a camera with radio control shutter

Kite aerial photography...?

I recall a magazine publishing an article on the subject some little time ago.

Only for commercial purposes.

Hi Michael. The Drone used in my Holiday vids was a DJI Mini 2. Under 250 grams. 4K 30 video. The controller is like a playstation controller. It takes your smart phone at the top & that is your viewing area.

You can switch midflight between photo or video. It has 2 times zoom. The Gimble on them is rocksteady. The video i posted was in Fuerteventura & it's always very windy there. Over 20mph but the Drone copes well with winds up to 22mph.

It is very easy to fly after a few tries at your local field. As usual i bought mine 2nd hand & has been great.

Not the cheapest Drone but very good. The Mini3 has just come onto the market & is even better with 4K 60, & has a 1/1.3" x 1.7 lens.

The other good thing about the DJI is the batteries are smart. Lithium polymer. If you have them fully charged & don't use the Drone for a whil the batteries automatically drop to 90%. After a few weeks of not using they drop further to i think 60%. So the batteries will have a long life.

I took the simple test online without much knowledge & passed. So i do have my flyer id & drone i.d. But it is not actually needed for under 250Grams weight. With those you can fly over buildings / over people . But not over crowds. The app tells you when it is safe to fly I.E how many Satellites it's picked up & return to home has been set. Any flight paths where you should not fly. It even brings up a Google map on the screen. You can toggle between the camera & the map to see where you are.

In Conclusion they are an amazing little Drone , as i am sure some others are too. I think Autel do a nice one.

It turned into a bit of a Hobby for me & so far no regrets buying it. They must be the ultimate tool for surveying building walls , brickwork, windows & roofs. Or even area's. Flight time is around half an hr per battery. Height unlimited but regs say 400 ft max. Distance . Some guys on you tube fly them up to around 4 miles & back. Not legally though.

Hope this is of some help.

Steve.

As an alternative have a look at Promap.co.uk. A friend used there location mapping services when he worked creating updated building service plans. They can supply location maps and many other types of ariel views for a price, nothing to loose looking at the web site.

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That’s one of the reasons I was interested in the 249g one that Steve mentioned.

MichaelG.

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Not really convenient … I specifically want nadir images from identifiable locations and [say] 10m altitude.

MichaelG

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Which might make the £250 that I have been quoted for a ‘Drone Survey’ more reasonable than I thought

… more research required

MichaelG.

O.K. … for clarity here are some numbers for the immediate need

The site is a thin quadrilateral, approximately 476 square metres, with a perimeter of about 109 metres

[ values derived from Google Earth ]

… I am guessing that a flight altitude of 10m would be reasonable, but am open to advice from the wise.

Google Earth satellite images don’t have enough resolution, but the Street-View quality would probably suffice.

I will be doing a traditional survey, but want drone images to supplement it.

MichaelG.

Lot's of rules and regulations - even after Brexit - but what actually happens in real cases such as Michael's? A small piece of private land that needs quickly surveying from 10 metres height. End of.

Do people just go ahead anyway and feign ignorance?

Something approaching the quality of the ‘Roof Surveys’ on this page would be fine:

**LINK**

https://mortimerphotography.com/services/drones/drone-roof-survey-footage/

MichaelG.

10mtrs is fine. As long as nothing around is higher. Easy to fly back or sideways to hit if so.

I survey the area & set a height above the highest point.

With 4k you will get stunning clear shots & photo,s.

The ones I did on hol over the sea are very clear at around that height.

Steve.