[time-nuts] Survey plot as art.
holrum at hotmail.com
Sun Jan 8 22:41:07 EST 2017
The Adafruit receiver outputs NMEA format data. The lat/lon values are sent as dddmm.mm format (ddd=degrees, mm.mm=minutes) This restricts the resolution of the values. Some receivers and newer NMEA specs support more digits past the decimal point. Receivers that support native binary formats that report lat/lon as 32-bit floats show similar quantization.
The Thunderbolt has a command for entering the receiver position, but it uses 32-bit floats. This restricts the accuracy that you can enter a position. Lady Heather's precision survey routines can calculate a position to greater accuracy. In order to save the high-accuracy calculated position it uses the rather nasty technique of doing single-point self-surveys until one happens to be within a foot or so of the calculated position.... that can take an indeterminate amount of time to happen, but eventually gets the job done.
> The Adafruit plot seems to have quantization. Are the values being
"snapped" to a grid in any way?
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