To check on the right coordinates of OS active stations, see the link below 
http://gps.ordnancesurvey.co.uk/active.asp

Conversions:
http://gps.ordnancesurvey.co.uk/etrs89geo_natgrid.asp

Base station data not 1 second resolution?  Resample (interpolate using posgps).  While this doesn't improve the data, it apparently makes it more evenly applied (no internal interpolation?).  Unverified.

== Short notes on processing ==

 1. Understand what you're doing!
 1. Create new project, aim at <data dir>/applanix.  Name should be '''"YYYYJJJ.ppc"'''.  Both filename kernels should be '''"YYYYJJJ"'''.
 1. Hit "Extract"
   1. Kernel should be '''"YYYYJJJ"'''.
   1. Read through output for errors - key things to look for are data gaps (if large, you may have to split the processing)
 1. Hit "POSGPS"
   1. Convert input files to GPB (File -> Convert -> Raw GPS to GPB)
   1. Plane applanix
     1. Set receiver type to autodetect
     1. Point at the applanix/Extract directory (check this!) and 'Auto add all' (this should add a NovAtel OEM3 file)
     1. Select the Novatel file, click options and ''Make all epochs Kinematic'' (this is because the Novatel is the sensor on the plane, which is definitely kinematic!)
     1. Run the conversion (check output for errors)
   1. Base stations
     1. Set receiver type to autodetect
     1. Point at the base station directory, probably Rinex, and 'Auto add all' (this should add a file, probably Rinex for the UK)
     1. Run the conversion (check output for errors, some health warnings are ok)
  
     

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Todo: add in detailed notes from Applanix training course