Stage 4 meteorite candidates review

Introduction

Stage 4 is the in situ visit of meteorite candidates that remain after the remote sensing assessments. To facilitate this, a GPS-enabled slippy map is used. The map has background satellite imagery, with drone survey images overlaid on top, and an interactive layer for the meteorite candidates.

Accessories list

  • Android mobile device (1 pp):
    • Android 11 or later.
    • Ideally good gyro and compass, for a better navigation experience. Cheaper devices usually skimp on these sensors (for example: Samsung S series devices are okay, but not the A series).
    • Most people prefer a tablet over a phone for this task.
    • At least a couple of GB of free space to cache candidates for offline (each cached candidate uses ~40 MB).
  • Power bank + charging cable.
  • Personal Locator Beacon or Satellite phone (1 pp).
  • Hand-held UHF radio (1 pp) + charger.
  • Garmin GPS unit (1 pp) + spare AA batteries, or equivalent (bulletproof GPS device that will get you back to camp).
  • Water, clothing, first aid kit etc. as appropriate for the site and conditions.

What to do

Set up

_Note: Android trusts apps from the Google Play Store by default and warns about apps from anywhere else, so you may have to update some settings along the way to install the app (or even just to download it, use Firefox instead of Chrome).

Before heading out, while you have good internet

  • Go to the Basecamp tab
  • Claim a batch of candidates you want to visit (do not exceed 100). Clicking on them individually, or draw a polygon around an area and “Claim inside”.
  • Hit the download button .
  • The Map should now have everything you need.
  • Make sure you have all the safety equipment from the Accessories list.
  • Do not rely on the app for returning to camp. Set a home point on GPS unit (+ on your phone as backup).
  • Let someone know which general direction you are heading towards, and when you are expecting to return. For a small team (≤3) verbal is fine. For larger teams, use some sort of written system (whiteboard for example).

While out

  • Check in with others regularly using UHF.
  • Revise planned loop if it is taking longer than expected.
  • When walking longer distances (for example between camp and candidates cluster), avoid constantly looking at your devices. Use the direction arrow to point towards your destination, and spot a distant landmark to walk towards. During this time you can turn the screen off (saving battery), and crucially you can keep a eye on where you put your feet!
  • Visit candidates. Record if it is a meteorite or not (+optionally take a picture). Finding the candidate is not always straightforwards, as the drone images’ georeferencing could be a couple of metres off, depending on how the survey was conducted; so you may need to figure out what the offset is based on other features in the image.
  • Find a very convincing meteorite looking rock? Follow the procedure. Radio your location so other team members can come and find you.

Coming back to camp

  • Charge devices.
  • Synchronise your results ( tab).
  • Release the candidates you are no longer planning to visit in the Basecamp tab.
  • (optional) Clear the cache in the Settings, to free up space on the device.
  • Check up on others.
  • Rest.

Note: if an inconsiderate user has claimed candidates that they are not actually visiting, you can ask a survey core member to release claims from this person on the web version

If using the web browser version

The web version of stage 4 has more or less the same functionalities as the mobile app, except that it is browser-based. This means that it cannot cache the data very well. Use only if you can maintain an internet connection.