Difference between revisions of "Drone Meteorite Searching"

Revision as of 02:12, 28 November 2024

Introduction

Main Survey Data Collection

Drone Image Survey Requirements

Ground resolution: 2 mm /pixel
Overlap: 10%
Minimum sun elevation: X degrees (to avoid long shadows creating too many false positives. Ignore if overcast). Use https://www.sunearthtools.com/dp/tools/pos_sun.php to calculate survey start/end times for your location.
GPS tagging of the images (Exif)
Timezone set to UTC

Note:

Survey strategy

When the data is processed, the oldest images are somewhat prioritised. Hence the higher priority/probability areas should be surveyed first.

The simplest way to achieve this is to cut the search area polygon into 5-20 smaller polygons, depending on the size of the survey. Try not to make the polygons too elongated.

Training Data Collection

True images (meteorites)

Pack list

Meteorites OR meteoritic shaped rocks (meaning a rock between 2 and 10 cm diameter, with no elongated axis, or sharp edges)
2 people: one drone pilot, one pointer.
black spray paint (matte or shiny).
a drone
a cardboard box and some gloves can be useful to avoid making a mess with the painted rocks

Capturing true training data

Final resolution should be between 1.8 mm/pix and 2.2 mm/ pix resolution, know your drone, know your resolution. If using the M300 with the 50 mm lens, your altitude should be between 18 and 30 m.
If you have real meteorites with fresh fusion crusts, place a meteorite and point to it at least 3 m away, then pick up the meteorite to re-place it, to then take the next picture
If you have fake meteorites (i.e. spray-painted rocks) place them in a line near different background objects (limestone rocks, saltbush, grass tuft, hole, lichen colony, etc) at least 3 m apart from the others, then walk next to the line and point to each rock
The pointer should walk slowly, pointing to the rock nearest to them, the drone flyer should take only one image per rock, and should call out to the pointer if the pointer moved too quickly and the flyer was unable to take an image, otherwise the flyer should confirm ‘good’ once they have taken an image fo the current rock in question
Between images, rotate the drone by up to 90 degrees to change the angle of shadows in the image
When labelling (drawing a box around the rocks) make sure to include the shadow the rock makes, that will help distinguish the rock from holes in the ground or other features that have no shadow. -> TODO move that bit to the webapp documentation.

False Images (non meteorites)

Fly in a perimeter around the fall zone and take images every 10-30 seconds.
If the search area displays significant variations in ground features (rock type, vegetation), try to capture as much of these different backgrounds as possible.

Low-resolution Survey

(optional) Needed to make a background map of the survey area (used as a layer on slippy map on Webapp).

Data Collection

Ground resolution: 5 cm /pixel
Overlap: 70%

Data Processing

Upload and process the data on WebODM (cloud version).
Download the data product: Orthomosaic (large geoTiff file).
Upload geoTiff to Mapbox: https://studio.mapbox.com/tilesets/
Wait for processing, note the Tileset ID, make sure it is public, and put that ID somewhere... TBD

WebODM setup

feature-type: orb
use-fixed-camera-params: enable
sfm-no-partial: disable
skip-3dmodel: enable
skip-report: enable
fast-orthophoto: enable
dsm: disable

Meteorite Candidates Follow-up

Webapp Deployment

See deployment notes: https://github.com/desertfireballnetwork/dfn-meteorite-drone-webapp/tree/main/webapp

GPU machine Deployment

Heavy lifting jobs (Machine Learning training and inference) need a GPU desktop or beefy VM. This machine just needs to be connected to the internet, and will work as a slave wrt the webapp on the VM.

See install notes: https://github.com/desertfireballnetwork/dfn-meteorite-drone-webapp/tree/main/mldaemon

Checklists

Misc

Computer things

Laptop + backup laptop. Linux distro, ~1TB free space, SD card reader. On DFN VPN, with relevant people's public keys authorized so remote debugging can happen.
Spin-up Webapp VM.
Start high-performance GPU computer (lab), and/or reserve a g2.xlarge GPU VM on Nectar (https://dashboard.rc.nectar.org.au/project/reservations/). Start the client (see #GPU_machine_Deployment).

Comms

Starlink unit.
Starlink ethernet adapter.
Re-activate Starlink subscription that should be on pause (ask Hadrien).
WiFi router with WAN port and swappable antenna (SMA).
high-gain 2.4GHz WiFi antenna.
hand-held UHF radios (1 pp) + charger.

Power

Generator.
Petrol and/or diesel. Usage: ~X litres / 12h
Battery station + cables (notably XT90 to Anderson plug connector).
Rhonda roof-rack solar system: ~300W panel + MC4 fuse + MC4 extension leads + MC4 to Anderson adapter (all of this should be mounted permanently on Rhonda and not removed).

Drone

Drone.
Drone camera + lenses.
Drone controller.
RTK base station.
Batteries (charge them just before the trip).
Battery charger.
SD cards.
Something to make a landing pad (e.g. tarp).
stuff for making ground control points (for the low-res survey)

@@ Line 38: / Line 38: @@
 * a cardboard box and some gloves can be useful to avoid making a mess with the painted rocks
+==== Capturing true training data ====
 * Final resolution should be between 1.8 mm/pix and 2.2 mm/ pix resolution, know your drone, know your resolution. If using the M300 with the 50 mm lens, your altitude should be between 18 and 30 m.
 * If you have real meteorites with fresh fusion crusts, place a meteorite and point to it at least 3 m away, then pick up the meteorite to re-place it, to then take the next picture
@@ Line 45: / Line 45: @@
 * Between images, rotate the drone by up to 90 degrees to change the angle of shadows in the image
 * When labelling (drawing a box around the rocks) make sure to include the shadow the rock makes, that will help distinguish the rock from holes in the ground or other features that have no shadow. -> TODO move that bit to the webapp documentation.
 === False Images (non meteorites) ===