Missing speed values

[routeconverter]

Comparison of the two sets of data shows missing positions (i.e. not consecutive seconds), missing speeds and missing height. Note that the NMEA sentances have been created by me from other data and therefore may not be syntactically correct!

Thank you for your explanation. There are two effects that cause this:

Your data contains checksums with lowercase characters like in

$GPGGA,132713,5509.7861,N,00140.5854,W,1,07,1.0,98.9,M,,M,,*7d

which were ignored by RouteConverter. I have created a new prerelease that accepts lowercase characters, so more from your data is read.

Your data contains invalid checksums like in

$GPRMC,132713,A,5509.7861,N,00140.5854,W,2.1,278.3,010110,,*e

which are ignored by RouteConverter.

There background for this decision is here:

There is a provision for a checksum at the end of each sentence which may or may not be checked by the unit that reads the data. The checksum field consists of a '*' and two hex digits representing an 8 bit exclusive OR of all characters between, but not including, the '$' and '*'. A checksum is required on some sentences.

So if you download the latest prerelease and fix the checksums of your NMEA sentences all positions are displayed with speed information.

I think that there are 'filters' which eliminate consecutive positions which are within a tolerance?

Yes, but the tolerance is zero: consecutive NMEA sentences with the same Latitude/Longitude values are joined.