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version 2.0, and a few other typos corrected

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Tom Early 2025-08-13 10:06:39 -07:00
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@ -108,7 +108,7 @@ draw=black]
\vhEntry{1.4}{01 Jan 2025}{SP5WWP}{Removed the KISS appendix and created a separate KISS specification document.}
\vhEntry{1.5}{11 Feb 2025}{N7TAE|VK7XT}{Rearranged the Data Link and Application Layer chapters for better flow, removed IP Network chapter and File Type appendix, added more details to Packet Mode, 3 new IP packets defined, and added new clarifying bit tables.}
\vhEntry{1.6}{08 Aug 2025}{SP5WWP}{Section 3.4 was moved to Part II.}
\vhEntry{1.7}{12 Aug 2025}{N7TAE|N7ADJ|SP5WWP}{GNSS Meta data changed extensively. Values are now metric, and a new param related to HDOP was added.}
\vhEntry{2.0}{12 Aug 2025}{N7TAE|N7ADJ|SP5WWP}{GNSS Meta data changed extensively. Values are now metric, and a new param related to HDOP was added.}
\end{versionhistory}
\chapter{Licenses}
@ -1373,15 +1373,15 @@ The second byte starts with a $4$ bit \textbf{Validity} field. Bit $1000_2$ is s
The next three bits of the second byte is the numeric \textbf{Radius} field. This radius is an estimate of lateral position uncertainty and is based on the horizontal dilution of precision (HDOP) value provided by the GNSS module. HDOP measure is based on the number of received satellites and their geometric position relative to the receiver. Note: the HDOP value (and therefore radius) is only a coarse estimate and in some cases might not reflect the actual uncertainty metric.
The last bit of the second byte is the most significant bit of the $9$ bit \textbf{Bearing} numeric field. This bit is combiled with the third byte to define value of bearing. 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 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 $24$ bith \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).
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).
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.
A $12$ bit \textbf{Speed} numeric field, $0..495$ is in the twelfth byte and the $4$ most significant bits of the thirteen byte. The decoded values range from 0.0 to 2047.5 km/hr in 0.5 km/hr steps.
A $12$ bit \textbf{Speed} numeric field is in the twelfth byte and the $4$ most significant bits of the thirteen byte. The decoded values range from 0.0 to 2047.5 km/hr in 0.5 km/hr steps.
Finally, the remaining $4$ bits of the thirteenth byte and the fourteenth byte are reserved and should be set to zero.