[LINK] RFI: Quality in Emergency Phone-Location

[Roger Clarke]

A young woman was missing for 6 days just outside Canberra.

Within 24 hours of her being reported missing, it was established that her mobile phone was last activated at 11:33am, 8km west of Black Mountain Tower.  (This is in the Molonglo River valley - mostly open country, but pretty steep in parts, just upstream from the confluence with the Murrumbidgee).

Searches were conducted in the area, with no success.

On the 6th day after she went missing, "authorities get more precise information on where her phone last contacted a tower, and are able to narrow their search considerably".

The ABC report refers to them "reanalysing Ms Bautista's phone signal history".

But the key quote is: "We were able to see where the signal was intersecting between Black Mountain and Isaacs Ridge, and those areas and the timings of those signals enabled us to say with some certainty that Kat's phone was in that location", Constable Ryan said.

The Isaacs Ridge area is about 10km S of Black Mountain.  The area they then shifted to was 8km SW of the middle of the earlier zone.  That's a correction of about 40 degrees in angle and 10km in distance (8 to 18km).

The new search-area is pretty awful country on a fairly steep hillside, and in the 'care' of ACT Forestry - which means radiata pine, few insects and birds, and periodic clear-felling.  

SES volunteers quickly found her upturned car off the road and down a gully, and shortly afterwards found her.  She had some injuries and hence had limited ability to walk up the ridge.  She had access to creek-water, and was apparently pretty well after 6 days in the open with no food.


I'm wondering how come it took 5 extra days to get "more precise information on where her phone last contacted a tower".

I'm assuming that we can discount the possibility that the analytical techniques are so massively compute-rich that the computer took that long to spit the answer out.

The data-search performed by the operator of the cell-phone network didn't turn up the Isaacs Ridge tower data the first time?

The AFP took the first data that came to hand, and ran with that?
And no-one was left in the office to keep looking through the data?


http://www.canberratimes.com.au/act-news/missing-canberra-teenager-kathleen-bautista-found-alive-20150911-gjk81q.html

http://www.abc.net.au/news/2015-09-11/missing-canberra-teen-kathleen-bautista-found-alive/6767864

https://www.google.com:443/maps/place/Settlement+Rd,+Paddys+River+ACT+2620,+Australia/@-35.3350336,149.0469701,12z/data=!4m2!3m1!1s0x6b17b782708d26f7:0xd35718f45f455376


-- 
Roger Clarke                                 http://www.rogerclarke.com/
			             
Xamax Consultancy Pty Ltd      78 Sidaway St, Chapman ACT 2611 AUSTRALIA
Tel: +61 2 6288 6916                        http://about.me/roger.clarke
mailto:Roger.Clarke at xamax.com.au                http://www.xamax.com.au/ 

Visiting Professor in the Faculty of Law            University of N.S.W.
Visiting Professor in Computer Science    Australian National University