Smartphone Avalanche Search Apps—A Review

7/27/2019 Smartphone Avalanche Search AppsA Review

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Box 2759, Revelstoke, BC V0E 2S0 ph: (250) 837-2141 / fax: 1-866-366-2094 [email protected] / www.avalanche.ca

SmartphoneAvalancheSearchAppsAReviewJamesFloyer,PhD

SeniorForecaster:CanadianAvalancheCentreDiscussionpaper:October,2013

IntroductionSmartphonesarepopularinCanada,around56%ofpeopleuseone

1.Recently,appshaveappearedon

themarketdesignedtoallowonesmartphonetosearchforanotherinavalancherescuescenarios.Inthis

way,usersaregivenavalanchevictimsearchfunctionalityontheirhandhelddevice.Therearecurrently

threeappsavailable:iSisIntelligent(Mountain)RescueSystem;SngAvalancheBuddy;andSnoWhere.

TheiSisandSngappsareavailableforiPhoneonly.SnoWhereisanAndroidonlyapp.Suchappsare

referredtoassmartphoneavalanchesearchapps.Thispaperpresentsatechnicaldiscussionoftheoperationandlimitationsofthesedevices.Thesuitability

ofthistechnologyisanalysedfromapublicsafetypointofview.Existingliteraturewasreviewedandapp

developerswere

contacted

to

provide

detail

on

how

their

systems

work

as

well

as

test

results2.

Technical

andrescueexpertswereconsultedforspecificadvice.Nofieldtestingwascarriedoutaspartofthis

review,anddetailsofhowthesystemsworkaregleanedinpartthroughmarketingliterature,including

videospostedondeveloperswebsites,andinpartthroughtheoreticalconsiderations.Notealso,atthe

timeofpreparation,noindependenttestsorreviewswereavailable.

HowtheyworkSmartphoneavalanchesearchappsmakeuseofvarioustwowaycommunicationtechnologiesincluding:

cellnetwork;WiFi;andBluetooth.Additionally,twooftheappsmakeuseofGPSsignals.Eachappusesa

slightlydifferentsetoftechnologiestocommunicateitslocationtoanothersmartphone,whichmustalso

havetheidenticalappinstalled.Table1liststhetechnologiesthedifferentappsmakeuseof.

WhensearchingusingWiFiorBluetoothsignals,asmartphoneapppermitssearchesinasimilarwaytoan

olderstyleanalogueavalanchetransceiver.Signalstrengthmaybedisplayedasanumber(SnoWhere)or

onabarchart(Sng),withanincreaseinsignalstrengthindicatingincreasingproximitytothevictim.

Signaldirectionispoorlyresolved,assmartphonesonlyhaveoneantenna(percommunication

technology),andtheorientationofthatantennamaynotbeknowntotheuser.

TheSnoWhereandiSisappsuseGPStoaidsearchlocation.Thelocationofthevictimshowsupona

basemap,allowingthesearchertousemappingfunctionstoguidethemtowardsthevictim.

Twoappsalsoincludefunctionalitythatnotifiesotherrescuersofanavalancheincidenteither

automatically(iSis)ormanually(SnoWhere).Thesefeaturescouldbeusefulwithinthebroadercontextof

searchand

rescue,

including

avalanche

search

and

rescue.

However,

since

this

paper

focuses

on

the

victim

searchfunctionalityofsmartphoneavalanchesearchapps,thesefeaturesarenotconsideredfurtherhere.

1GoogleReport:OurMobilePlanetUnderstandingtheMobileConsumer.IpsosMediaCT.May2013.

2Twoofthethreeappdevelopers:PiranhaStuffBV(Sngsdevelopers)andCharcoalFrostLtd(SnoWheres

developers)respondedtoourenquiries.


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Table1:Summaryofsearchandcommunicationtechnologiesemployedbythreeavalanchesearchapps.

App Primarysearch(Range) Finesearch NotificationiSis

(iPhone

4/5)

GPSlocationsentbyWiFiorcell

internet

connection

(1000

m

claimed)

ordirectviaBluetooth(45mclaimed)

Microgridsearch

using

Bluetooth

Automatic(usingtrajectory

analysis)

alert

from

victim

or

manualalertfromrescuer

Sng

(Android)

WiFisignalstrengthanalysis(50m

claimed)

Sameasprimary None

SnoWhere

(iPhone

3/4/5)

GPSlocationsentbyBluetooth(40m

claimedforiPhone3,45mforiPhone

4and5)

Mapassisted

Bluetoothsignal

strengthanalysis

Rescuercansharelocation

usingemailorSMS

RangeissuesWiFiandBluetoothsignalsarestronglyaffectedbytransmissionthroughwaterbasedmediums,including

snow.Therefore,signalstrengthisreducedwhenthetransmittingdeviceisburiedinanavalanche;this

effectis

amplified

if

the

debris

is

dense

and

moistoften

the

case

for

all

but

the

smallest

avalanches.

Signalstrengthisalsoaffectedbythepresenceoftrees,rocksorthevictimsownbodylyingoverthetop

oftheirphone.

Intheirmarketingmaterials,developersreportrangesofbetween40and50mforWiFi/Bluetooth

searches.Theserangeslikelyreflectbestcasescenariosforrelativelyshallowburials,ordevicesplacedon

thesurfaceofthesnow.SngAvalancheBuddydevelopershavereportedthatforestedterrainpresents

difficultiesforWiFitransmission.Effectiverangewasreducedtoaround12mduringtheirtestsin

forestedterrain.Whileindependenttestshavenotbeencarriedout,similarrangereductionsmightbe

expectedfordeepburialsinavalanchedebris,and/orwhenthedeviceisshieldedbyavictimsbody.

SimilarrangereductionsareexpectedforBluetoothsignals.

GPSaccuracyisinsufficientforprecisevictimlocation.SnoWheredevelopersclaimabestreported

accuracyof5mwithaniPhone4/5.Accuracyvaluesof7.5to15mareprobablymorerealisticfor

devicesburiedunder2mofsnow,sinceGPSperformancedegradesrapidlywithburialdepth3.Searchers

willstillhavetoswitchtoWiFi/Bluetoothsignalsearchmodeforthefinesearchphase.IftheGPSisnot

alreadyswitchedonandtracking(whichrequiresconsiderablebatterypower),itmaytakesometimeto

acquireasignalwhenburied,ifitisabletodosoatall.

GPStechnologyoffers,atbest,acoarsesearchfeaturetobringthesearchertowithinapproximately10m

ofthevictim.Atworst,ifaGPSlocationwereincorrect,searcherscouldactuallybeledawayfromthe

victim,believingtheyweremovingclosertowardsthem.

CompatibilityInternationalstandards

4dictateavalanchetransceiverstransmitandreceiveatafrequencyof457kHz.

Regardlessofbrand,allcurrentavalanchetransceiversarecompatiblewitheachother.Compatibility

3Schleppe,J.andLachapelle,G.GPSTrackingPerformanceunderDepositedSnow.IONGNSS,Sept.2006.

4ETSIEN3007181V1.2.1.ElectromagneticcompatibilityandRadiospectrumMatters(ERM);AvalancheBeacons;

Transmitterreceiversystems;Part1:Technicalcharacteristicsandtestmethods.EuropeanStandard

(Telecommunicationsseries).May2001.


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betweentransceiversisafundamentaltenetofavalancherescue;evenolderanaloguetransceivers5

operateonthe457kHzfrequencyandarecompatiblewithmorerecentdigitalmodels6.

Incontrast,smartphonesdonottransmitat457kHzandthereforedonot(andcannot)adhereto

internationaltransceiver

standards,

regardless

of

what

software

is

installed.

Theyarenotcompatiblewith

457kHzavalanchetransceivers.Further,smartphoneavalanchesearchappsarenotcompatiblewitheachother.Thismeansallmembers

ofabackcountrypartymustusethesamesmartphoneplatformwiththesamesoftwareinstalledtohave

auseablerescuesystem.Thiscreatesheightenedpotentialforsomeonetoassumetheyhavea

compatiblesmartphonedevice,whileinactualfacttheyhaveadifferentandincompatibledevicetothe

onesusedbytheircompanions.Thisincompatibilitywithexistingavalanchetransceiversandlackofinter

compatibilitybetweentheappsmakestheseapplications,attheircurrentlevelofdevelopment,

particularlyinadequatefromanavalancherescueperspective.

BatterylifeBatterylifeisanothercriticallimitationwiththecurrentstateofsmartphonetechnology.International

standardsforavalanchetransceiversdictatethatdevicesshouldbeabletotransmitfor200hoursat

+10Candthenstillhaveenoughpowertosearchfor1hourat 10C.Manysmartphonebatteriesdonot

lastforafulldayofuseononecharge,especiallywhenpowerintensivefeatures,suchasGPSlocation,

BluetoothorWiFicommunicationmodesareemployed.Batterydrainishigherinareaswithnocell

coverage,asphonesconstantlyseekasignal.Theeffectofthecoldfurtherreducesbatterylife.Many

phones(includingiPhonemodels)donothaveuserreplaceablebatteries.

SARgroupsreportrescuevictimsfrequentlyhavetroublecommunicatingwithrescuersattheendofthe

dayastheirsmartphonesrunoutofbatterypower.AdventureSmart,CanadasnationalSARprevention

program,recommendsusersswitchtheirphonesofftoconservebatterypowerincaseofemergency

situations.Usersofsmartphoneavalanchesearchappspotentiallyfaceanunacceptablechoice:switch

theirphoneofftoconservebatterypowerforcommunicationbutdisabletheiravalanchesafetydevice,or

maintainpowertotheiravalanchesafetydevicebutruntheriskofnothavingeffectivecommunication

foremergencyrescueuse.

Robustness,reliabilityandeaseofuseInternationalavalanchetransceiverstandardsincludestringentdropandimmersionteststhatmustbe

passedbeforeanydevicecomestomarket.Additionally,devicesmustincludeacarryingsystemdesigned

toguardagainstbeingrippedoffduringanavalanche.Whilesomesmartphonemodelsarereasonably

robust,manyarenot,andmaybesusceptibletowateringressorshock.Whilesmartphoneoperating

systemsaregenerallygood,softwarecrashesdooccur,sometimesrequiringareboot;thesemaybe

causedbyotherinstalledsoftwareandnotnecessarilytheavalanchesearchappitself.Ifthiswereto

happenduringarescue,valuablesearchtimewouldbelost.Phonesarenotsuppliedwithacarrying

5457kHzwasadoptedbytheInternationalCommissionforAlpineRescue(IKAR)in1986.Somemodels

manufacturedbeforethatdateoperatedat2.275kHzandarenotcompatiblewith457kHztransceivers.6TheCanadianAvalancheCentrerecommendstheexclusiveuseof3antennadigitaltransceivers(withnobrand

preference),duetotheirincreasedperformanceinarangeofburialscenarios.


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system,increasingthepossibilityofthedevicebecomingdetachedfromthevictimduringanavalanche,

ordroppedinthesnowduringasearch.

Mostsmartphonesrelyontouchscreens,whicharenotoperablewearingthickglovesormittensandmay

notwork

effectively

ifthe

screen

is

covered

with

snow

or

water.

The

large

size

of

screens

creates

vulnerability,astheymightbeeasilycracked.Totheircredit,appdevelopersappeartohavefavoured

relativelysimpleinterfacesfortheirsoftware;however,itmaystillbenecessarytonavigateamenu

system,orturnadditionalsoftwareorphonefeaturesofftoproperlyoperatetheavalanchesearchapp.

Thereisthepossibilityfordistractionfromanincomingcall,emailortextduringasearch,whichmightbe

lesseasilyignoredifthesmartphoneisinuseintherescuershandratherthanstashedawayinapocket

orbackpack.

InterferenceRecentstudies

7,8haveanalysedtheeffectsofinterferenceonavalanchetransceiverperformancefora

rangeofdevicesincludingcellphones.Basedonthesestudies,theCanadianAvalancheCentre

recommendsthe

following

separation

distances

between

an

avalanche

transceiver

and

other

electronic

devices:

Transmitmode(Send):20cm

Searchmode(Receive):50cm

Itisnotknownforcertainwhetherdedicatedavalanchetransceiverswouldexperienceadditional

problemsifusedinproximitytosmartphonesrunningavalanchesearchapps.However,since

WiFi/Bluetoothfrequencies(~2.4GHz)arequitedifferentfromthe457kHzfrequency,theriskof

additionalinterferencefromtheproximaluseoftheseappsisprobablylow.(Note:aspreviouslystated,

smartphoneavalanchesearchappsareNOTcompatiblewith457kHztransceivers.Thediscussionhereis

whethertheincidentaluseofsuchanappwouldhaveanimpactonasearchbetweentwoormore

dedicated457kHztransceivers.)

InterferencebetweenBluetoothandWiFisignalshasbeendocumentedandoccursbecausetheoperating

frequenciesareclosetogether.Thisshouldnotposeaproblemifonlyonecommunicationtechnologyis

usedatanyonetimeandtheothertransmittingmodeisswitchedoff.However,otherinstalledapps,or

featuresactivatedbytheusermayturnWiFiorBluetoothsignalson,increasingthepossibilityof

interference.OtherpossiblesourcesofinterferencearereceivingacellphonecallandusingtheGPS

receiverandotherBluetoothenabledelectronicdevicescarriedbyusers,suchascameras,headphones

etc.theeffectoftheseonsmartphonesearchappperformanceiscurrentlyunknown.

MarketingAvalanche

search

apps

are

being

actively

marketed

as

software

that

turns

asmartphone

into

an

avalanche

transceiver.Noneofthedevelopersclaimthesoftware/phonecombinationwilladheretointernational

transceiverstandards.Infact,atleasttwodevelopershavespecificdisclaimersthattelltheuserthe

systemisnotcertifiedanddoesnotmeetinternationalstandardsforavalanchetransceivers.Despitethe

7Barkhausen,J.TheEffectofExternalInterferenceonAvalancheTransceiverFunctionality.InProceedings

InternationalSnowScienceWorkshop(ISSW2012).Anchorage,AK,USA,Sept.2012.8Genswein,M.,Atkins,D.,Obad,J.,Grady,E.,Piche,M.,Guyn,T.,Whelan,R.andBrattlien,K.Recommendation on

howavoidInterferenceIssuesinCompanionandOrganizedAvalancheRescue.2013.


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disclaimers,themarketingintentionsarequiteclearfromtext,videosanddiscussionsondevelopersweb

pages,Facebookaccounts,andothercommunications:theseappsarebeingtoutedspecificallyforusein

findingburiedvictimsintheeventofanavalanche.

Onemarketing

statement

from

the

Google

Play

store

about

the

Sng

Avalanche

Buddy

states:

Sng

is

a

missingpersontrackertool.Atooldesignedtoquicklylocateandfindavictim,buriedunderan

avalanche.SnoWheredevelopersincludethispersonalavalancheconnectionstatement:20yearsago

ourfounderwasburiedinanavalanchewithinboundsinpoorvisibility.Heonlysurvivedbecausehewas

quicklydiscoveredbyapassingboywhothoughthehadfoundahat.ThatexperienceinspiredSnoWhere:

tohelpensurenooneelsessurvivalreliesonluck.iSisdevelopersareprobablythemostaggressivein

pitchingtheirappasadedicatedavalancherescuesystem,andincludeaprofessionallyeditedvideo9

containingamockavalancheincidentwithagroupofskierswhohaveapparentlylefttheconfinesofthe

resort.Theincidentiscompletewithimagesofaskiertriggeringanavalancheandbeingburiedbysnow,

beforehiscompanionsusetheirphonewiththeiSisapptorescuethevictim.

LegalandethicalissuesWhileitisclearthatavalanchesearchappsarebeingactivelymarketedassoftwarethatenables

smartphonestobeusedasavalanchesearchdevices,thelegalstatusofmarketing/sellinganappthat

turnsanotherwisecompliantsmartphoneintoanavalanchesearchdevicethatdoesnotmeet

internationalstandardsisunclear.Additionally,itisnotasimplemattertoestablishwhetherinternational

standardsforavalanchetransceiversarebindingorvoluntaryintheCanadiancontext.Specificlegal

advicewouldberequiredtoestablishthesepointsinCanada.

Regardlessoflegalstate,developersdohaveanethicalobligationtoensureproductstheybringtomarket

donothaveanegativeimpactonpublicsafety.Foralifesavingdevicewithmissioncriticaloperating

parametersthatreliesonsuccessfulcommunicationwithothersimilardevices,independenttestingin

realworld

scenarios

is

imperative.

None

has

been

made

available

to

us,

and

to

our

knowledge

none

has

yetbeencarriedout.Thenumerousandseriousflawsinthecurrentstateofsmartphoneavalanche

searchapptechnologygivejustifiablecauseforconcernthatpublicsafetymaybecompromisedbythe

introductionofthiskindofavalancherescuedevice.

ConclusionanddiscussionTheCACdoesnotconsideranyoftheexistingappsdiscussedheretobeviabledevicesforavalanche

companionrescue.Thereareseriousconcernsandvulnerabilitieswitharangeofimportantaspectsofthe

technology.Themostcriticaloftheseare:

lackofcompatibilitywithexistingavalanchetransceivers

lack

of

compatibility

between

different

operating

systems

and

software

brands

smartphonebatterylife

rangeconcernsinrealworldscenarios(i.e.whenburiedinavalanchedebris)

Additionalconcernsare:systemrobustness;smartphonereliability;easeofuse;interferenceissues;and

thepossibilityofdistractionduringasearch.

9http://www.youtube.com/watch?v=qpqnszYXdmg&feature=player_embedded


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Therearegoodreasonsforhavinginplaceinternationalstandardsforavalanchetransceivers.Ofcourse,

standardsmaychangeandevolvewithtimetoreflectnewtechnologies.Butthismustbedoneina

transparent,collaborativemannerthatmaintainsatitscorethebestinterestsofpublicsafety.Present

development

of

smartphone

avalanche

rescue

apps

appears

haphazard,

is

unregulated,

and

is

potentially

dangeroustoendusers,whomayconfusethistechnologywithlegitimateavalanchetransceivers.The

optiontospendonlyafewdollarsonacheapappinplaceofspendingseveralhundredsofdollarsona

dedicatedavalanchetransceivermaybetemptingtomany,particularlynoviceusers.However,thechoice

tousesuchanappasasafetydevicewhenenteringavalancheterraincouldimperilallmembersofthe

usersbackcountrygroup.

Somemayarguethattheubiquityofsmartphonedevicesmightmakeupfortheshortfallinperformance

ofavalanchesearchapps.Underthispretext,thelikelihoodofanavalanchevictimbeingwithoutanyform

ofavalancherescuedeviceislower,whichcompensatesforanyreducedsearchperformance.This

argumentisinvalidforthefollowingreasons.

First,the

critical

issues

of

cross

compatibility,

inter

compatibility,

poor

battery

life

and

range

underavalanchedebrisprecludeanykindofbenefitfromsmartphoneubiquity.

Second,appsmustbemanuallyinstalledandactivated,sosmartphoneubiquitydoesnotequate

toaubiquityofavalanchesearchdevices.

Third,onaccountoftheurgencyofavalanchecompanionrescuewithtargetrescuetimes(i.e.the

combinationofsearching,pinpointlocationusingaprobeandextricationbydigging)of10

minutesorless10,substandardavalanchesearchdevicesarelikelytohaveaconsiderablenegative

impactonvictimmortality.

Fourth,thereispotentialforasignificantnegativeimpactonusersofdedicatedavalanche

transceiversbythepresenceofsmartphoneavalanchesearchapptechnology:thatisthe

possibilityforpeoplewhowouldhaveotherwisepurchased(orborrowedorrented)adedicated

avalanchetransceivertobetemptedtodownloadanappontotheirsmartphoneinstead.These

peoplemaynotbeawaretheirsmartphonesearchappisnotcompatiblewithothergroup

membersdedicatedavalanchetransceivers,soputtingthemselvesandtheircompanionsatrisk.

RecommendationsInlightofthedeficienciesofcurrentsmartphoneavalanchesearchapptechnology,theCanadian

AvalancheCentreisimplementingthefollowingstrategies:

1. Maintaintheprevailingcultureofusingdedicated457kHzavalanchetransceiversduringwinter

backcountryrecreationbycontinuingtopromotetheCanadianAvalancheCentresandother

partnersexistingawarenesscampaignsthatrecommendtheuseofdedicatedavalanche

transceivers,probes

and

shovels

for

all

group

members.

2. Discouragetheadoptionofsmartphoneavalanchesearchapptechnologyinplaceofdedicated457kHztransceivers.Thismighttaketheformoftargetededucationcampaignsdirectedat

specificusergroups.Campaignsshouldhighlightthebenefitstousersofdedicated457kHz

transceiversoversmartphoneavalanchesearchapps.

10Haegeli,P.,Falk,M.,Brugger,H.,Etter,HJ.ComparisonofavalanchesurvivalpatternsinCanadaandSwitzerland.

CanadianMedicalAssociationJournal.doi:10.1503/cmaj.101435. Mar.2011.


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3. Respondtomediaandpublicenquiriesregardingthisnewtechnology,includingbeingprepared

torespondintheeventofanincidentinvolvingavalanchesearchapps,eitherinCanadaor

elsewhere.

4. Advocate

that

new

avalanche

search

technologies,

especially

those

that

deviate

from

agreed

uponinternationalstandards,bedevelopedcollaboratively,thoroughlyandwithtransparency.

Developersmustberemindedoftheirethicalobligationtoensurefullandindependenttestingof

theirrescuesystemspriortogoingtomarket.

Documents

Smartphone Avalanche Search Apps—A Review