GPSの研究　その41

#概要
GPSを理解したかった。
初めて、rtk測位できた。rtkpostだけど。

#写真

![output2.jpg](https://qiita-image-store.s3.amazonaws.com/0/18104/f3265faf-f5d8-48fd-5acb-0ff93a5aff99.jpeg)


#手順1　ubxファイルを作る。
7月10日14：00から17：00まで
neo-6m,9600ボー,com4,1秒間隔でデータを取得。
u-centerを使う。
COM4_180710_091452.ubx
が出来た。

#手順2　rinexファイルに変換。
rtkconvを使う。
COM4_180710_091452.obs
COM4_180710_091452.nav
が、出来る。

#手順3　電子基準点データを取得する。
ftp://terras.gsi.go.jp/data/G_2.11/2018/191/0198191g.18n.gz
ftp://terras.gsi.go.jp/data/G_2.11/2018/191/0198191g.18o.gz
を落とす。解凍する。
0198191g.18n
0198191g.18o
が、出てくる。

#手順4　rtkpostで測位する。

```
# rtkpost options (2018/07/10 22:51:53, v.2.4.2)

pos1-posmode       =kinematic  # (0:single,1:dgps,2:kinematic,3:static,4:movingbase,5:fixed,6:ppp-kine,7:ppp-static,8:ppp-fixed)
pos1-frequency     =l1+l2      # (1:l1,2:l1+l2,3:l1+l2+l5,4:l1+l2+l5+l6,5:l1+l2+l5+l6+l7)
pos1-soltype       =forward    # (0:forward,1:backward,2:combined)
pos1-elmask        =15         # (deg)
pos1-snrmask_r     =off        # (0:off,1:on)
pos1-snrmask_b     =off        # (0:off,1:on)
pos1-snrmask_L1    =0,0,0,0,0,0,0,0,0
pos1-snrmask_L2    =0,0,0,0,0,0,0,0,0
pos1-snrmask_L5    =0,0,0,0,0,0,0,0,0
pos1-dynamics      =off        # (0:off,1:on)
pos1-tidecorr      =off        # (0:off,1:on,2:otl)
pos1-ionoopt       =brdc       # (0:off,1:brdc,2:sbas,3:dual-freq,4:est-stec,5:ionex-tec,6:qzs-brdc,7:qzs-lex,8:vtec_sf,9:vtec_ef,10:gtec)
pos1-tropopt       =saas       # (0:off,1:saas,2:sbas,3:est-ztd,4:est-ztdgrad)
pos1-sateph        =brdc       # (0:brdc,1:precise,2:brdc+sbas,3:brdc+ssrapc,4:brdc+ssrcom)
pos1-posopt1       =off        # (0:off,1:on)
pos1-posopt2       =off        # (0:off,1:on)
pos1-posopt3       =off        # (0:off,1:on)
pos1-posopt4       =off        # (0:off,1:on)
pos1-posopt5       =off        # (0:off,1:on)
pos1-exclsats      =           # (prn ...)
pos1-navsys        =1          # (1:gps+2:sbas+4:glo+8:gal+16:qzs+32:comp)
pos2-armode        =continuous # (0:off,1:continuous,2:instantaneous,3:fix-and-hold)
pos2-gloarmode     =on         # (0:off,1:on,2:autocal)
pos2-bdsarmode     =on         # (0:off,1:on)
pos2-arthres       =3
pos2-arlockcnt     =0
pos2-arelmask      =0          # (deg)
pos2-arminfix      =10
pos2-elmaskhold    =0          # (deg)
pos2-aroutcnt      =5
pos2-maxage        =30         # (s)
pos2-syncsol       =off        # (0:off,1:on)
pos2-slipthres     =0.05       # (m)
pos2-rejionno      =30         # (m)
pos2-rejgdop       =30
pos2-niter         =1
pos2-baselen       =0          # (m)
pos2-basesig       =0          # (m)
out-solformat      =llh        # (0:llh,1:xyz,2:enu,3:nmea)
out-outhead        =on         # (0:off,1:on)
out-outopt         =on         # (0:off,1:on)
out-timesys        =gpst       # (0:gpst,1:utc,2:jst)
out-timeform       =hms        # (0:tow,1:hms)
out-timendec       =3
out-degform        =deg        # (0:deg,1:dms)
out-fieldsep       =
out-height         =ellipsoidal # (0:ellipsoidal,1:geodetic)
out-geoid          =internal   # (0:internal,1:egm96,2:egm08_2.5,3:egm08_1,4:gsi2000)
out-solstatic      =all        # (0:all,1:single)
out-nmeaintv1      =0          # (s)
out-nmeaintv2      =0          # (s)
out-outstat        =off        # (0:off,1:state,2:residual)
stats-eratio1      =100
stats-eratio2      =100
stats-errphase     =0.003      # (m)
stats-errphaseel   =0.003      # (m)
stats-errphasebl   =0          # (m/10km)
stats-errdoppler   =10         # (Hz)
stats-stdbias      =30         # (m)
stats-stdiono      =0.03       # (m)
stats-stdtrop      =0.3        # (m)
stats-prnaccelh    =10         # (m/s^2)
stats-prnaccelv    =10         # (m/s^2)
stats-prnbias      =0.0001     # (m)
stats-prniono      =0.001      # (m)
stats-prntrop      =0.0001     # (m)
stats-clkstab      =5e-12      # (s/s)
ant1-postype       =llh        # (0:llh,1:xyz,2:single,3:posfile,4:rinexhead,5:rtcm)
ant1-pos1          =90         # (deg|m)
ant1-pos2          =0          # (deg|m)
ant1-pos3          =-6335367.6285 # (m|m)
ant1-anttype       =
ant1-antdele       =0          # (m)
ant1-antdeln       =0          # (m)
ant1-antdelu       =0          # (m)
ant2-postype       =llh        # (0:llh,1:xyz,2:single,3:posfile,4:rinexhead,5:rtcm)
ant2-pos1          =37.9636081999998 # (deg|m)
ant2-pos2          =140.09352581 # (deg|m)
ant2-pos3          =200.306000001131 # (m|m)
ant2-anttype       =
ant2-antdele       =0          # (m)
ant2-antdeln       =0          # (m)
ant2-antdelu       =0          # (m)
misc-timeinterp    =off        # (0:off,1:on)
misc-sbasatsel     =0          # (0:all)
misc-rnxopt1       =
misc-rnxopt2       =
file-satantfile    =
file-rcvantfile    =
file-staposfile    =
file-geoidfile     =
file-ionofile      =
file-dcbfile       =
file-eopfile       =
file-blqfile       =
file-tempdir       =
file-geexefile     =
file-solstatfile   =
file-tracefile     =

```

以上。