KAP & UAV

The problem with UAV:

You can pop down to Maplins and get yourself a DJI Phantom and go fly, shooting video and stills as you whiz  flawlessly across your favorite landscape: what’s not to like? The shots you get from the sky are awesome and you can stick the thing anywhere- low level aerial photography couldn’t be simpler right?

Kevins DJI shot

DJI 4 Image by Kevin Lajoie (Aeriali)

https://www.flickr.com/photos/ningaloo/

Up to a point: take your Dji to a popular event, say a football match or an open air concert- this is going to be great: you are going to capture the scene no one else can- you are an aerial photography God! Look at the tiny people below! see how the crowds look up and point at your peerless command of the skies! ..and you are breaking the law …and the police will shut you down.

p39 of CAP 722 (March 2015) states :

For operations in congested areas, a small unmanned aircraft (SUA) operator will need to apply to the CAA for permission to fly a camera-equipped SUA (i.e. a small unmanned surveillance aircraft  (SUSA)):

Over or within 150 metres of any congested area.

Over or within 150 metres of an organised open air assembly of more than 1,000 persons.

When not engaged in take-off or landing, within 50 metres of any person, vessel, vehicle or structure which is not under the control of the person in charge of the aircraft (during take-off or landing this may be reduced to 30 metres or less if attendant persons are under the control of the person in charge of the aircraft).

A short version is published as a leaflet:

CAP 1202 -2

CAP 1202 -1

The full document (166 pages)  : https://www.caa.co.uk/March 202015.pdf

Short form ‘You have control’ leaflet: http://www.caa.co.uk/docs/1995/CAP%201202UAVsafetyrules.pdf

The CAA and the police are taking this seriously. Recent prosecutions by both the CAA (successful) and Police (on going) :

At the time of posting there is no further news on the prosecution of Nigel Wilson since the adjournment to set a trail date on May 7th 2015- what happened?

So you need a shed load of clearances to fly the thing over people, buildings and pretty much any thing other than empty countryside. If you think you can get your drone to pay for lunch you need some important paperwork too:

A recent statement from Historic England:

“Where the use of drones is deemed useful to a project this is only carried out by contractors who:

  • hold a current and valid ‘Permission for Aerial Work’ (PFAW) and can provide
  • evidence of valid insurance cover
  • a risk assessment for the proposed flight; and
  • a method statement outlining what equipment will be used and a flight plan outlining where flying is proposed.

If any of these are not provided they are not allowed to fly – end of!”

…and that’s before you have consent for photography.

So, in short, the drone is easy to use but operates in a fog of red tape put in place for perfectly sensible safety reasons. Certainly you can shoot great footage, there is rarely a news feature on TV that isn’t backed by wonderful tracking aerial views : the ‘crane shot’ has been replaced by the drone shot.

The good news is that, in the UK,  it is possible to clear the hurdles and get the required permissions (as the ubiquitous TV footage shows) it costs a few bob but aerial survey work can be achieved with great results at much lower cost than aeroplane charter. Not so good is the position is some of the US states where outright bans on non-military use are coming into force.

The restrictions on UAV can make KAP a realistic alternative and a fair few people are now looking at KAP as alternative to low elevation aerial cover.  For some applications this might be a good idea, archeological recording of open sites is a good case in point, others are small scale topographic mapping of landscape swaths around 5 Ha in size. KAP is very dependent on local site conditions and because of this needs to be carefully considered along with balloon aerial photography (BAP)  and pole aerial photography (PAP) as alternatives to UAV.

Differences between KAP and UAV/UAS

Regulation:

  • In the UK kites are limited to 60M AGL and 30m AGL within 3 miles of an operational aerodrome or air traffic control zone. That’s it.
  • Photography from a public place is largely unrestricted, overflight of private property requires permission. Note that bans on flying model aircraft and kites are in place on many nature reserves and public parks.
  • ‘Permission for Aerial Work’ (PFAW) not required.

Safety: A KAP risk assessment should reflect

  • the danger to persons of the area swept by the line
  • The ‘attractive hazard’ of an object in the sky
  • The ‘distraction hazard’ to those operating machinery
  • The ‘wildlife impact’ of an object in low the sky
  • possible failure of kite/line and impact of camera on persons or property
  • procedures employed to ensure safe elevation and recovery of camera
  • Rapid avoidance maneuvering is limited, aircraft under CAA minimum height (600m) may be at risk.

KAP camera positioning

  • Limited to down wind zone
  • height limited
  • cannot be maneuvered where overhead lines, trees, buildings etc interrupt the sweep of the flying line
  • requires a clear stand off from subject
  • desired position may not be possible without repeated attempts in different wind directions
  • height varies with wind speed, may not be regular throughout a swath
  • proximity to buildings, people etc not restricted ( within the limits of safe operation)

KAP Operation

  • takes practice to estimate height/distances for camera positioning
  • dependent on wind
  • can only be scheduled by a ‘possible flight window’
  • precise performance cannot be predicted easily
  • choice of appropriate lifter to match wind speed, height and reach needs practice.

Reliability: Scheduling and programming KAP can be fiendishly difficult, you are at the mercy of the elements for lift and light.

  • Typical required wind speed for 1kg camera:  7-12mph
  • Wind direction should place target downwind of flier
  • topography of some sites (e.g. in ‘wind shadow’) can make launches difficult or impossible
  • video cover can be achieved but the stability of the KAP platform is nothing like as good as from a drone.

Quality of KAP cover/ the KAP swath

  • Photo-scale variation caused by height variation can be excessive
  • Down wind offset/bias is common, images tend to  ‘cluster’ in a down wind corner of the site
  • Site boundaries or flight cone limits (trees, fences over head wires etc) can result in  pinned anchor points which can force oblique cover
  • Consistent overlap difficult
  • High resolution frames can be captured with heavy camera if needed.
  • Height limit reduces the cover per frame.

Some advantages over UAV

  • Payload, 1kg camera rig is easily achievable
  • low cost platform, a typical KAP kite is around £100
  • flight duration: can be sustained for hours
  • Swath capture possible provided access is clear.
  • Simple operation

Compared to flying a drone, KAP is different. Yes flying a kite is pretty straight forward but knowing how much kite to use, what it takes to lift a payload and how to handle line, catenary etc all takes patience and practice, you cannot expect quality capture ‘straight out the box’ : some basic skill must be acquired to get the hang of placing the camera where its needed and learn the ‘go/no-go’ constraints of site, wind and safety. Learning how a kite and camera can ‘fit’ a site takes practice.

Anenometer

KAP needs a keen eye for the wind..

The kite fliers agenda compels close engagement with the site. I believe the conditions for KAP are so specific it engenders a much more considered reconnaissance process than for any other aerial capture (with the possible exception of BAP) method. Getting to know a site is important. Understanding the environment with respect to KAP takes time and that time is valuable as part of the kite fliers unique experience of the landscape.

The photographic agenda. A good UAV pilot would make similar consideration of lighting, vegetation state etc. but the ability of UAV to fly in poor conditions means there will be a tendency to fly in poor light. A good Kapper is compelled to work when the wind lets him (or her) and so makes a much more careful choice of flight time.

Cost, accessibility and skill transfer. Like a drone almost anyone can fly a kite but at considerably less expense. KAP should be considered as part of the documentation tool set along with BAP and PAP: photographic capture and photogrammetric processing  are primary site recoding tools regardless of the origin of the imagery.

Model and pics

A typical KAP swath cluster

KAP releases aerial capture from restrictive UAV Regulation. In the UK this is a major benefit as any contracting archaeologist would need full CAA certification to proceed- KAP just needs landowner consent in most cases- nothing more.

Contour overlay _01

Topographic survey of small sites is achievable by KAP.

I’m not saying ‘grab a kite and fly a camera over the next football match’…you’d still need permission to do that, but the kite offers the aerial photographer an option with a bit less paper work. By and large the police are not likely to give you too hard a time if they deem the risk to public safety not to their liking: they can always find you at the end of the string!

Parking the drone and flying the kite. Following the FAA ban on UAV in the USA,  KAP and BAP have proved a viable alternative for forensic aerial imaging:

Since the FAA placed a ban on all commercial use of drones, Randy Anglin, a retired DPS officer who now specializes in surveillance security, crime-scene analysis and accident reconstruction, began researching other ways to capture video and images from above.

By using kites and balloons, Anglin has found a loophole as big as the Arizona sky.

http://www.azcentral.com/story/joedanareports/2015/02/24/12-news-drones-surveillance/23963337/

KAP Accident investigation record by Randy Anglin

B

About billboyheritagesurvey

Heritage worker
Gallery | This entry was posted in KAP, Survey Practice and tagged , . Bookmark the permalink.

3 Responses to KAP & UAV

  1. Kevin says:

    Just wanted to mention to the blog watchers here that I am a practising KAP ninja and not just a (PFAW holding) drone monkey!

    Kites are still my #1 🙂

  2. Randy Anglin adds by email:

    I got into KAP and BAP to fill a void that was created by new regulations on UAVs. Initially I felt that if KAP would be a viable option 10% of the time I could recover my investment in two years. I have found that for the kind of work I am doing (forensic reconstruction) I am able to use KAP most of the time (+80%), assuming I have some wiggle room. I recovered my initial investment quickly and now teach classes on using KAP/BAP for surveillance. Although we started with UAVs in 2005 I don’t see investing in new equipment anytime soon, as tethered equipment has proven to be very effective.

    All the best,

    Randy Anglin,

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