PostProcessingandbringingthe DataintoGIS

Butwait

thattoppartoftheroutewasnttherebefore!

Original

Final

Unfortunately,GPSisnotfoolproof

Unfortunately,GPSisnotfoolproof

Butitseasytospotmistakesinthedata

Thereisadrasticchangeineverycolumn

Butitseasytospotmistakesinthedata

Thereisadrasticchangeineverycolumn

PostProcessing

HavingqualityGPSdatasometimesrequires postprocessing

Software,madebytrimbleorotherswilldo thisforyou

Itiseasytodoonyourown,ineitherExcelor GoogleEarthorGIS

PostProcessingTheGPSlogs

apointatthe giveninterval.

Thesoftware drawsapath, asabestfit

line

PostProcessingThepointsandlinesinGoogleEarthare

organizedintofoldersjustliketherestof Windows

Creatingthefinishedproductrequires creatinganewfolder,andcopyingand pastingthedesiredpointsandlinesintoit.

Thetimeittakesdependsonhowlong(in time)yourpathis,andtheinterval.

Thisparticularmapwasanhourlongbus ride,withonepointpersecond=approx3600

points.Itiseasytofindthepathandthebusstops,

becauseGoogleEarthgivesthemdifferent symbols

BringingthedataintoGISforanalysis

DescriptiveFileName.csv

Reformatthedata Itseasierthanitsounds TheGPSunitformatsLatsandLongsdifferently

thanwedotheyjustuseE/W,N/Sinsteadof negatives

GISdoesnotlike/

incolumnheadings,andwill notunderstandtheLatLongcoordinatesunless

theyarereformatted.Change42.687161,N,73.827057,W,To42.687161,73.827057 ThisprocesscanbeautomatedinMSWord

usingtheFindandReplaceFunction.

AddthefiletoGISasnormal

Rightclickonthefile,andclickDisplayXYData Changeittoacoordinatesystemtomatchyour

maporothershapefiles

Dontworrythatyouhavepointssofarawayfromeachother,

everyGPStesthasbadpointsatthebeginningandtheendof therun

(Thisdatawasnotpostprocessed)

Onceyoufindthevaliddata,zoominandyou willfindwhatyouarelookingfor

Ifyouhavedoneeverythingcorrectly,adding otherlayerstothemap,suchasStreetmaps, shouldlineupperfectly.

Rightclickthefilename,MouseoverData,andclickonExportData.Addthelayertothe

map.Nowyouwill

beabletoeditthe

dataorrelateitto

othertables.

Post Processing and bringing the Data into GISBut wait that top part of the route wasnt there before!Unfortunately, GPS is not foolproofUnfortunately, GPS is not foolproofBut its easy to spot mistakes in the dataBut its easy to spot mistakes in the dataPost ProcessingPost ProcessingPost ProcessingBringing the data into GIS for analysisReformat the dataAdd the file to GIS as normalSlide Number 13Slide Number 14Slide Number 15Once you find the valid data, zoom in and you will find what you are looking forIf you have done everything correctly, adding other layers to the map, such as Streetmaps, should line up perfectly.