4 files changed, 60 insertions, 0 deletions
diff --git a/doc/Makefile b/doc/Makefile
index a09380cf..5b264e02 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -3,6 +3,7 @@
 #
 
 RELNOTES_INC=\
+	release-notes-1.8.1.inc \
 	release-notes-1.8.inc \
 	release-notes-1.7.inc \
 	release-notes-1.6.8.inc \
diff --git a/doc/altusmetrum-docinfo.xml b/doc/altusmetrum-docinfo.xml
index 3c230f1a..595422f1 100644
--- a/doc/altusmetrum-docinfo.xml
+++ b/doc/altusmetrum-docinfo.xml
@@ -47,6 +47,14 @@
 <revhistory>
   <?dbhtml filename="altusmetrum-revhistory.html"?>
   <revision>
+    <revnumber>1.8.1</revnumber>
+    <date>27 Aug 2017</date>
+    <revremark>
+      Fix Apogee Lockout time value wrapping bug. Change high-speed
+      Kalman filter function.
+    </revremark>
+  </revision>
+  <revision>
     <revnumber>1.8</revnumber>
     <date>12 Aug 2017</date>
     <revremark>
diff --git a/doc/release-notes-1.8.1.inc b/doc/release-notes-1.8.1.inc
new file mode 100644
index 00000000..d9e4a2d9
--- /dev/null
+++ b/doc/release-notes-1.8.1.inc
@@ -0,0 +1,47 @@
+= Release Notes for Version 1.8.1
+:toc!:
+:doctype: article
+
+	Version 1.8.1 includes an important bug fix for Apogee Lockout
+	operation in all flight computers. Anyone using this option
+	must update firmware.
+
+	This release also contains a change in how flight computers
+	with accelerometers deal with speeds around and above Mach
+	1. In previous versions, the flight computer would completely
+	disregard the barometric sensor above 330m/s (around Mach
+	1). Now, the data from the barometric sensor is reduced in
+	effect without ever going away entirely. This prevents early
+	drogue deployment for flights which spend considerable time
+	above Mach 1.
+
+	1.8.1 also contains a couple of minor fixes for AltosUI when
+	analyzing saved data files.
+
+	== AltOS
+
+	AltOS Bug Fixes
+
+	* Handle time value wrapping in Apogee Lockout
+          correctly. Without this, apogee lockout would sometimes
+          prevent any drogue charge from firing.
+
+	* Change Kalman filter on flight computers with accelerometer
+          to continue using the barometric sensor even at high speeds
+          to avoid unintentional drogue deployment during
+          deceleration.
+
+	== AltosUI and TeleGPS Applications
+
+	AltosUI New Features
+
+	* Add new 'Huge' font size to make text even bigger on high
+          resolution monitors.
+
+	AltosUI Bug Fixes
+
+	* Prevent some crashes when reading older saved flight data
+          for graphing or KML export.
+
+	* Load frequency preference at startup. The loading code was
+          broken, so you'd see only the default frequencies.
diff --git a/doc/release-notes.inc b/doc/release-notes.inc
index e52e36b5..adcf57ed 100644
--- a/doc/release-notes.inc
+++ b/doc/release-notes.inc
@@ -2,6 +2,10 @@
 == Release Notes
 
 	:leveloffset: 2
+	include::release-notes-1.8.1.raw[]
+
+	<<<<
+	:leveloffset: 2
 	include::release-notes-1.8.raw[]
 
 	<<<<