botic — What the drone lets you see

Case study · photovoltaic roof

A roof photo, or a survey that actually serves ?

Plenty of people can fly a drone over a roof. What changes the outcome is knowing what you are looking at. Here, the state of the panels was not the point — most of what mattered was happening around them.

Flat industrial roof in bituminous membrane, fully covered with rows of tilted photovoltaic modules, several white rooflights set among them, and a concrete parapet with no guardrail in the foreground. — **The installation, whole**Rows running to all four edges, rooflights hemmed in by the array, no clear perimeter anywhere. The overview does not yet say where the problem is : it says there are several, and where to go looking.overview

Edge of a flat roof: the last row of modules stops a few dozen centimetres from the concrete parapet, a bundle of red and black cables runs directly on the membrane along the supports. — **The edge, and what runs along it**The last row stops less than a metre from the drop, with no guardrail and no lifeline. The DC harness runs along the row directly on the membrane, unfixed in places, to two penetrations a few dozen centimetres from the parapet.HSSE · cabling

Rectangular galvanised metal frame sitting on the bituminous membrane, with no dome or grille, in the middle of the equipped area; on the left, a smoke vent hemmed in by modules and the cable bundle running down to two penetrations. — **An open frame, in the middle of the array**No dome, no grille, no marking. On the left, a smoke vent hemmed in by panels : whether it can still open fully comes before any question of yield.unguarded opening

Fall protection

No guardrail on the parapet, no visible lifeline, and panels laid right to the edge. Every intervention — cleaning, swapping an inverter, checking torque — happens at the edge of the drop, on a membrane the rain makes slippery.

Walkways and access

No dedicated walkway. To reach a middle row you walk between the modules, on the waterproofing, stepping over cables. The work position is reachable ; the route to it is not.

DC cabling

A harness resting on the bitumen along the whole row, unfixed in places. Under UV and abrasion, a sheath eventually gives — and a DC insulation fault does not switch off the way an AC circuit does.

Openings and smoke vents

An unguarded open metal frame, and smoke vents with panels less than a metre away. Two separate matters : falling through the opening, and smoke ventilation that has to open fully.

Interface with the waterproofing

Feet and rails sit directly on the membrane, and the cables pass through it. Those details, not the modules, decide how long the roof lasts — and they are the most expensive to put right once the array is down.

What the photo does not settle

Actual ballast in edge and corner zones, the wind-load calculation, cable cross-sections, earthing, commissioning records. The image shows what is visible ; compliance is read in the file. The survey tells you which documents to ask for.

What is delivered besides the images

A reading, not a generated report. Findings are marked on the shots themselves, at the exact spot where they read, with the enlargement taken from the original photo.

A hierarchy. What puts people at risk first, what damages the installation next, what costs yield last. The three are not handled at the same pace, nor by the same trades.

Follow-ups you can act on. The points to be closed out, the documents to request from the installer, and what belongs to a qualified professional rather than to a flight. The drone observes ; it does not sign off an installation.

Roof covering and metalwork

The whole slope, then the slate

The overview is not there to conclude: it is there to say where to look closer. Both scales come from the same flight, seconds apart.

Slate slope seen three-quarters from the ridge, regular pattern, gardens and neighbouring buildings at the top of the frame. — **The whole slope, in one shot**Pattern, overlap, alignment of the courses. At this scale you diagnose nothing — you spot where the pattern breaks, and come back to it.overview

A loosened cylindrical zinc part lying across the slates of a slope, gutter and arris visible. — **A loosened part, left lying on the slope**Harmless until it slides — but it is the piece missing from wherever it came from, and that place has to be found.defect spotted

Hipped end of a slate roof: two zinc hips converge on the ridge, safety hooks fixed to the courses. — **Hips, valleys and hipped ends**Junction lines are where water gets in. They are photographed square to the pitch, which no position on the ground allows.detail points

Lower part of a slope in old slate; the gutter running along the stone wall is filled with soil, roots and growth. A white hook lies on the slates. — **The eaves gutter, full**Soil, roots and growth in the gutter; higher up, a loosened hook on the slope. A full eaves survey fits into a few minutes of flying.maintenance

Thermography

The thermal camera opens nothing : it says where to open

The images below are raw readings, with no temperature attached. A quantitative survey is another thing : it demands a sufficient temperature difference, a chosen hour, a stated emissivity — and the calibration that goes with it.

Ribbed metal cladding shown in two halves: on the left the infrared image in orange and magenta bringing out ribs and fixings, on the right the same wall in grey in the visible spectrum. — **The same wall, two domains**Visible on the right, infrared on the left : ribs, fixings and the structure behind the sheet appear where the eye saw only uniform cladding.comparison

Infrared image of a roof: even purple background, sharp yellow edge, two clear orange patches and a fainter diffuse trace. — **Three signatures, three causes**Two sharp anomalies and one diffuse trace on an even background. They are not the same defects, and the image shows it before anything is opened.raw reading

Infrared reading of a wall, a black ellipse drawn on the image marks off a colder zone above a warm band. — **The area to open, drawn**The outline is drawn on the image, not recalled from memory. The roofer goes up to the marked spot rather than the assumed one.reporting

Chimney stacks

The highest element, and the least looked at

From the ground you see nothing of the crown. From a ladder leant against it, you see only one cheek. From straight above, it is all in one plane — capping slabs, flues, joints and flashings.

Vertical view of the crown of a stone chimney stack: two flues, the right one lined with a clay liner, the left one bare. Slates and lead flashing all around. — **The crown, vertically**Two flues : one lined with a clay liner, the other bare. The capping slabs, their joints and the surrounding lead all read on the same image.nadir view

Foot of a masonry chimney stack on a slope of new slate; the lead flashing and apron of the junction are visible, the masonry carries colonies of orange lichen. — **Flashing and apron**The lead junction between stack and covering, taken at an angle so the stack does not mask itself. The orange lichen marks the most exposed face.junction

Stone chimney stack at the top of a slate slope; two red lines connect one face of the stack to a circular enlargement showing eroded joints and loosened stones. — **The finding, annotated**Eroded joints on one face of the stack. The enlargement is taken from the shot itself : not a second photo, the same one, at its original resolution.reporting

Heritage and steeples

Structures you cannot otherwise reach

On a steeple, the scaffolding often costs more than the survey it enables. The flight gives the first reading — and sometimes that is enough to decide.

Slate church spire seen from above, its four faces converging on the point; street, houses and village roofs all around. — **The spire, from above**All four faces of the covering in one image, with the surrounding fabric to place the structure and judge access.nadir view

Face of a church belfry: arched opening topped with wooden louvres, stone surround, slate roofs below. — **Louvres and belfry openings**Slats, surrounds and sills at eye level, without a lift. That is almost always where water gets into a tower.elevation

Slate roof of a church nave, seen lengthwise from ridge to chancel; replaced slates appear lighter than the old ones. — **The nave in one piece**One longitudinal pass above the ridge. Replaced slates differ from the old ones in tone : the history of repairs reads off the image.overview

Masts and technical sites

Inspecting without climbing mostly changes the frequency

A climb has to be planned, secured and justified. A flight, far less so. You can look twice a year rather than only when work is due.

Top of a telecommunications mast carrying antennas and a dish, above forest stretching to the horizon. — **The site in its surroundings**Clearance, vegetation, line of sight to the horizon. The flight documents the setting as much as the structure — and sometimes it is the setting that has changed.setting

Mast seen vertically from above: the arms carrying the antennas form a star over the access track and the trees. — **The antenna plane, from directly above**Arm orientation, footprint of the fixings, condition of the supports. Geometry you cannot survey from the foot of the mast.nadir view

Underside of a radio unit mounted at the top of a mast: silkscreen for ports EAC, OPT1 to OPT4, ALIM and DC IN, optical connectors and labelled cables. — **Labels and connectors, legible**Optical ports, power feed, cable marking, earthing braid. At this distance the image answers the question without anyone climbing up to ask it.detail

A mission

What happens before and after the images

The shots on this page are the visible part. Most of the work is being able to take off on that day, at that hour, in that place.

Feasibility first

Geozones active in the target slot, the ceiling that actually applies, nature reserves, hour-by-hour weather. That is exactly what botic does — the tool grew out of these flights.

The flight

One overview pass, then the detail points one by one. Both scales come out of the same visit : coming back costs a second trip and a second weather window.

The sort

Many images, few useful views. What is delivered is sorted, oriented and named — not a copied memory card.

The reporting

Findings are marked on the image itself, with the enlargement taken from the original shot. What is shown is what was photographed.

Oblique aerial view of a village surrounded by fields and copses, under a broken sky, the horizon clear in the distance. — **And take-off is not a given**A ceiling lowered under an approach path, a nature reserve on no drone map, a military area active in the afternoon : the answer depends on the slot, not only on the place.preparation

Equipment

What these shots do not show yet

All of them predate the Matrice 4TD, which has since arrived. Three things change — and this page will change with them, mission by mission. A stated capability is not a shot : until there is an image, it stays inside this box.

Measurement, not just colour

Radiometric thermal sensor 640 × 512 : every pixel carries a temperature. The three readings above say “it is warmer here” ; the next ones will say by how much.

The detail without getting closer

Three focal lengths up to 168 mm, 112× hybrid zoom, and a laser rangefinder. Read a nameplate, or dimension a height, from the distance you are already at.

The same framing, two months later

IP55 and Dock 3 compatibility : a flight plan replayed identically. Two comparable images beat two visits that are not.

The four fields of work and the full equipment sheet : Services.

Limits

What these images do not replace

A stated limit beats an assumed coverage — on this page as on the rest of the site.

An image shows a surface, not what lies beneath it

The drone does not probe, dismantle, lift a slate or measure any thickness. It records the apparent state at the moment of the shot, in that moment's light. A damp roof structure under an intact covering cannot be seen from the sky.

The infrared readings shown here are qualitative : they locate differences, they do not quantify them. A usable measurement assumes a protocol — indoor/outdoor temperature difference, no recent direct sun, stated emissivity, calibrated equipment.

The diagnosis remains the work of a qualified professional : roofer, engineer, expert. These images serve to have them look in the right place, and sometimes to spare them the climb.

What the drone lets you see.And from how close.