diff --git a/M17_spec.pdf b/M17_spec.pdf index 558c400..2df960b 100644 Binary files a/M17_spec.pdf and b/M17_spec.pdf differ diff --git a/M17_spec.tex b/M17_spec.tex index cc2a897..39a573e 100644 --- a/M17_spec.tex +++ b/M17_spec.tex @@ -1375,9 +1375,9 @@ The next three bits of the second byte is the numeric \textbf{Radius} field. Thi The last bit of the second byte is the most significant bit of the $9$ bit \textbf{Bearing} numeric field. This bit is combined with the third byte and contains the bearing value. This is the heading direction for the velocity data in degrees and should never contain a value greater than 359. Zero is due north and 90 is due east, \textit{etc}. -The $24$ bit \textbf{Latitude} is specifed in the next three bytes (fourth through sixth). After the sign bit, the remaining $23$ bit numeric field is the binary fraction of $90$ degrees, where the value $0$ represents $0$ degrees latitude, \textit{i.e.}, the equator, and $8388607$, $2^{23}-1$, represents $90$ degrees, \textit{i.e.}, the poles. With $23$ bits, this is a resolution of approximately 39 milliseconds of arc (~1.2m). +The $24$ bit \textbf{Latitude} is specified in the next three bytes (fourth through sixth). After the sign bit, the remaining $23$ bit numeric field is the binary fraction of $90$ degrees in two's complement format, where the value $0$ represents $0$ degrees latitude, \textit{i.e.}, the equator, and $\pm8388607$ ($\pm2^{23}-1$) represents $\pm90$ degrees, \textit{i.e.}, the poles. With $23$ bits, this is a resolution of approximately 39 milliseconds of arc ($\sim$1.2m). -The $24$ bit \textbf{Longitude} follows in the seventh through ninth byte. After the sign bit, the remaining $23$ bits is the binary fraction of $180$ degrees, where the value $0$ represents $0$ degrees longitude, \textit{i.e.}, the prime meridian, and $8388607$ represents $180$ degrees. With $23$ bits, this is a resolution of approximately 77 milliseconds of arc (~2.4m at the equator). +The $24$ bit \textbf{Longitude} follows in the seventh through ninth byte. After the sign bit, the remaining $23$ bits is the binary fraction of $180$ degrees in two's complement format, where the value $0$ represents $0$ degrees longitude, \textit{i.e.}, the prime meridian, and $\pm8388607$ ($\pm2^{23}-1$) represents $\pm180$ degrees. With $23$ bits, this is a resolution of approximately 77 milliseconds of arc ($\sim$2.4m at the equator). A $16$ bit numeric \textbf{Alitude} field is in the tenth and eleventh bytes and decodes in $0.5$ meter steps, offset by $500$ meters. A value of $0$ is an altitude of $-500.0$ meters, while the largest value of $65535$ is an altitude of $31767.5$ meters.