The first known practical telescopes were refracting telescopes

It seems that GlassLens is a particular typed of Lens, and the block RefractingTelescope (which extends OpticalTelescope) has redefined the Type and multiplicity of the reference property lens:Lens[0..*] to lens:GlassLens[2..*], where it has been assumed that a RefractingTelescope has at least 2 lenses, as indicated by the stereotype keyword «pa:assumed» on an editorial Comment. If we were treating refracting telescopes in more detail we'd have to justify this at some stage, but for now we'll note these two supporting snippets from separate Wikipedia pages:

Wikipedia: 'All refracting telescopes use the same principles. The combination of an objective lens and some type of eyepiece is used to gather more light than the human eye is able to collect on its own, focus it, and present the viewer with a brighter, clearer, ...'

Wikipedia: 'An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device.'

Some SysML-fluent readers may ask why "only" AggregationKind 'shared' has been used here on lens:GlassLens[2..*], instead of making it a part property with AggregationKind 'composite'. The answer is that later we are going to have assemblies for containing parts like primary and secondary lenses and mirrors (including multi-element ones), so we don't want competing composition heirarchies.

I've also done it so that members of the SysML community who like to wage war on shared aggregation not having clear semantics have something to argue about at the pub (see also the linked specification references and separate tutorial slides about shared aggregation below).

Some other model elements such as Netherlands, Astronomy, and TerrestrialApplication have been elicited, with "semantic triple" Dependency keyword stereotypes «used for» and «invented in». We're not overly interested in representing the history of telescopes in this trail, but for the sake of illustration, the «invented in» stereotype has an attribute when so that one can assign a tagged value {when = "17th Century"}.

In the Webel Parsing Analysis recipe you are not obliged to map every single part of a Snippet's text extract to a UML or SysML model, just traceably elicit model elements of immediate or anticipated interest to your task or goal.

At regular intervals when using the Webel Parsing Analysis recipe for SysML^® you should pause and create dedicated "focus" BDDs for main blocks, as shown next .

Up next

Focus BDD for block RefractingTelescope

Notes

[DISPLAY, STYLE, TIP]{SUGGESTED} Webel Parsing Analysis: If the dashed-line "anchors" from your «snippet» ElementGroup symbols to elicited elements make a «pa» Parsing Analysis Diagram (PAD) too hard to read, try making them light grey using symbol properties.

[POLICY, STYLE]{STRICT} Webel Parsing Analysis «pa» diagrams are NOT intended as final presentation diagrams! They serve merely to traceably elicit model elements, which may then be shown in other (typically much tidier) presentation diagrams elsewhere.

[POLICY, STYLE]{STRICT} Webel «pa» Parsing Analysis Diagrams (PADs) are "scratchpads" used to elicit model elements traceably from text Snippets (extracts from source Documents). While BDDs are a good initial choice, most types of SysML diagram can be used as a «pa» diagram.

[POLICY]{TIP} In the Webel Parsing Analysis recipe you are not obliged to map every single part of a Snippet's text extract to a UML or SysML model, just traceably elicit model elements of immediate or anticipated interest to your task or goal.

Snippets (quotes/extracts)

The first known practical telescopes were refracting telescopes invented in the Netherlands at the beginning of the 17th century, by using glass lenses.

They were used for both terrestrial applications and astronomy.

All refracting telescopes use the same principles. The combination of an objective lens and some type of eyepiece is used to gather more light than the human eye is able to collect on its own, focus it, and present the viewer with a brighter, clearer, ...

An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device.