
The Location Engine: Some quick notes on trying the DW1000 - bborud
https://blog.exploratory.engineering/post/decawave/
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billconan
I do not understand the following:

> Tags are mobile and are used to track the physical location of whatever they
> are integrated in - with centimeter precision (DecaWave promises maximum
> 10cm error). A tag recevies location data and distance to anchors within
> range. An onboard location engine calculates the x,y,z position of the tag.

> You can choose to use the default location engine or you can roll your own.
> This is relatively straight forward if everything is on the same plane.
> Slightly less so in R3 space. Google “trilateration algorithm” or
> “multilateration algorithm” to get started. The IEEEXplore archive alone,
> has 400+ papers on the subject.

> If using the built in location engine, keep in mind that the units used for
> anchor coordinates and distance estimates are millimeters.

> The update frequency is a function of the number of tags in the network.
> Using only one tag results in 150 Hz updates. Using 750 tags, you get 0.2Hz
> updates. Deploy up 9000 tags in a given anchor cluster and the update
> frequency drops to 0.0167Hz, which is still more than reasonable for many
> applications.

Why is the update frequency a function of the number of tags?

Say I have a tag A, why the update frequency of tag A is a function of the
number of other tags (assuming we have tag B and C in the system.)? They
should be unrelated to each other, right?

If this technology is an analogy to GPS, tag A should only communicate with
Anchors, not other tags? And the anchors should only passively broadcast their
time?

~~~
jhayward
According to the DecWave web site [1] the anchors time stamp the arrival of
the tag's beacon and pass it to a central host for trilateration. So the
network is single-tasking, essentially.

[1]
[https://www.decawave.com/technology1/](https://www.decawave.com/technology1/)

~~~
naikrovek
Exactly right.

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avmich
Do they specify somewhere the maximum working range between tags and anchors?

