<p>This has happened every now and then to me, and the solutions ate a combination of using clickers like @Jakob Tougaard suggested, and also taking measurements as commented by @etgriffiths.</p>
<p>By measurements, I mean taking distances to landmarks with a laser range finder or tape. If the landmarks are slightly far away, you won't pick up small alterations in distance, but can realize bigger ones.</p>
<p>In addition to distance, you can also additionally take 'tilt-measurments' every now and then. Some range-finders come with tilt measurements in built too, which reduces the number of things you need to carry in the field.</p>

CC BY-SA 4.0
2022-07-10T07:55:46.990Z
2022-07-10T07:55:46.990Z
Thejasvi
<p>While walking backwards in the dark, I bumped into my  4-channel inverted T-shaped acoustic array placed on a tripod. The array has a central mic with 3 peripheral mics at 60 cm Radius at 120 deg intervals. (See sketch below).</p>
<img src="https://i.sstatic.net/wdqU5.png" width="300">
<p>(<em>Quick sketch of a 60 cm radius inverted T shape array geometry, photo to come. Red dots indicate mic positions on the frame.</em>).</p>
<p>The frame shook a bit, but seemed to remain more or less in the same position as it was. I'm a little worried now. The frame is rigid, and the inter-mic distances will remain the same. The 'pose' of the frame is my concern.</p>
<p>How much will this change the final coordinates of the localised bat calls?</p>
<p>What do you do in case something like this happens?</p>

CC BY-SA 4.0
2022-07-08T15:01:12.483Z
Can you remeasure the distances to make sure that they are the same? I'm not sure if you can do anything much if you suspect the tripod moved, except incorporate that into your margin of error.
etgriffiths
CC BY-SA 4.0
2022-07-08T15:11:58.173Z
This would be a neat answer! i also updated the question to clarify that the frame is rigid.
Thejasvi
<localisation><array><microphone>
Bumped into acoustic array during fieldwork - localisation issue?
# Bumped into acoustic array during fieldwork - localisation issue?

(Asked by: username_0 on 2022-07-08)

While walking backwards in the dark, I bumped into my 4-channel inverted T-shaped acoustic array placed on a tripod. The array has a central mic with 3 peripheral mics at 60 cm Radius at 120 deg intervals. (See sketch below).

![](https://i.sstatic.net/wdqU5.png)

(*Quick sketch of a 60 cm radius inverted T shape array geometry, photo to come. Red dots indicate mic positions on the frame.*).

The frame shook a bit, but seemed to remain more or less in the same position as it was. I'm a little worried now. The frame is rigid, and the inter-mic distances will remain the same. The 'pose' of the frame is my concern.

How much will this change the final coordinates of the localised bat calls?

What do you do in case something like this happens?

**Tags:** localisation, array, microphone

> **Comments:**
> **username_1**: Can you remeasure the distances to make sure that they are the same? I'm not sure if you can do anything much if you suspect the tripod moved, except incorporate that into your margin of error.  
> **username_0**: This would be a neat answer! i also updated the question to clarify that the frame is rigid.  

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## 1 answers

### Answer by username_0 on 2022-07-10. Score: 0

This has happened every now and then to me, and the solutions ate a combination of using clickers like @Jakob Tougaard suggested, and also taking measurements as commented by @username_1.

By measurements, I mean taking distances to landmarks with a laser range finder or tape. If the landmarks are slightly far away, you won't pick up small alterations in distance, but can realize bigger ones.

In addition to distance, you can also additionally take 'tilt-measurments' every now and then. Some range-finders come with tilt measurements in built too, which reduces the number of things you need to carry in the field.


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