questions about "Experiments on local positioning with Bluetooth"

[jun shen]

Hi Sushma,
Here are some of my questions about the paper.
Q1:in formula (4), what is the exact meaning of Zk? Is that the
observation value of state k?
Q2: in formula (7), why only using 1st order term of Taylor series?
if we use more terms, will that promise a more accurate value?
Q3: I dont understand how to obtain formula(9)? Can you help explain
that?

one general questions:
Q1: in most cases the scope of bluetooth(bt) is only around
10meters, the error range of 3.76meter seems a significant variation,
is the localization meaningful?

[Sushma Myneni]

Hi,

Q1:in formula (4), what is the exact meaning of Zk? Is that the
observation value of state k?

--> Yes, Zk represents the measurement state of the true state xk

 Q2: in formula (7), why only using 1st order term of Taylor series?
if we use more terms, will that promise a more accurate value?

---> Using first order gives more accurate values for a straight lines, where as for curves the second order gives better results

 Q3: I dont understand how to obtain formula(9)? Can you help explain
that?

 ---> We have to linearize the h(x) matrix using Taylor series and remove the higher order terms ( power greater than 1)

 one general questions:
  Q1: in most cases the scope of bluetooth(bt) is only around
10meters, the error range of 3.76meter seems a significant variation,
is the localization meaningful?

 --->Yes, error in positioning is too high, and as I have mentioned in today's class we need to improve the distance estimation metric. That is use RX power levels rather than trying to estimate them from RSSI values.

Thankyou,
Sushma