Skip to content

Commit ad62e7d

Browse files
committed
Adjust discussion of multi-star selection
1 parent 8196232 commit ad62e7d

File tree

1 file changed

+13
-10
lines changed

1 file changed

+13
-10
lines changed

help/Basic_use.htm

+13-10
Original file line numberDiff line numberDiff line change
@@ -596,10 +596,10 @@ <h4><a name="Simulators"></a>Simulators</h4>
596596
asked for a means to override guide star selection based on what they
597597
see on the display.&nbsp; These requests have not been acted upon
598598
because they would disrupt the underlying mathematics of the multi-star
599-
process. More importantly, they would lead to inferior results for
599+
algorithm. More importantly, they would lead to inferior results for
600600
reasons described below.&nbsp; The algorithm applies the basic
601601
principle that the accuracy of centroid calculation - the fundamental
602-
calculation of where a star is located on the sensor - it proportional
602+
calculation of where a star is located on the sensor - is proportional
603603
to that star's SNR.&nbsp; It has nothing to do with the shape of the
604604
star, its location on the sensor, its proximity to the sensor edge, or
605605
any other visual characteristics of the star candidate. The algorithm
@@ -608,7 +608,7 @@ <h4><a name="Simulators"></a>Simulators</h4>
608608
on a particular system.&nbsp; Two parameters, Min-HFD and Max-HFD,
609609
define a range of star "sizes" that control whether a bright area on
610610
the sensor can be accepted as a star candidate rather than being
611-
rejected as sensor noise, internal reflections, or close pairs of
611+
rejected as sensor noise, an internal reflection, or a close pair of
612612
stars.&nbsp; The third parameter, Saturation ADU, defines an upper
613613
limit to the peak brightness of a star candidate, usually defined as
614614
the maximum ADU value produced by the guide camera.&nbsp; The algorithm
@@ -620,7 +620,8 @@ <h4><a name="Simulators"></a>Simulators</h4>
620620
examining the PHD2 guide logs to see the range of star sizes that are
621621
typical for the guiding system and its seeing conditions. Once set,
622622
they should rarely need to be changed unless something in the
623-
configuration or the atmospheric conditions has substantially changed.<br><br>Users
623+
configuration or the atmospheric conditions has&nbsp;changed
624+
substantially.<br><br>Users
624625
are commonly fooled by what they see on the display and think they can
625626
do a better job of guide star selection.&nbsp; This is a mistaken
626627
impression.&nbsp; The single biggest reason is that many of the
@@ -631,13 +632,15 @@ <h4><a name="Simulators"></a>Simulators</h4>
631632
completely eliminate these artifacts. In summary, simply squinting at
632633
the screen and clicking on bright spots will produce inferior results
633634
compared to the quantitative, systematic approach taken by the
634-
auto-select star-finding mechanism.&nbsp; Of course, die-hard users can
635+
auto-select star-finding mechanism.&nbsp; Of course, skeptical users
636+
can
635637
still manually choose a guide star, but they won't then be able to use
636-
multi-star guiding. For people who are not convinced about the merits
637-
of the auto-select process, the debug log file contains a detailed
638-
list, for every auto-find, of the location and properties of every
639-
single candidate object in the guide frame and how these were included
640-
or excluded to compile the final list.<span style="font-weight: bold;"></span>
638+
multi-star guiding. For people who question&nbsp;the auto-selection
639+
process, the debug log file contains a detailed
640+
list, for every auto-find, of the location and properties of
641+
every&nbsp;candidate object in the guide frame and how these were
642+
included
643+
or excluded to compile the final list of usable guide stars.<span style="font-weight: bold;"></span>
641644
<h3><a name="Automatic_Calibration"></a>Automatic
642645
Calibration</h3>
643646
<h4>Conventional Mounts</h4>

0 commit comments

Comments
 (0)