22 January 2019

DSP Mobile: Plan & Equipment Libraries

As mention in an earlier post, Deep-Sky Planner Mobile Edition (DSPME) allows you to browse and import plans from the Plan Library in the Deep-Sky Planner Community at knightware.biz. This post discusses this and the ability to import equipment lists from the Community.

Accessing plans and equipment lists (resources) online is a simple process: first, you download a list of available resources, and then you can download the resource and store it on your device. Any of these resources can be deleted later if you like.

[Note: Screenshots for this post were made on a 10" iPad tablet with the BunkerGray app style. The Community is running on a test server.]

The Latest Plans in the Community

You can scroll through the list of plans to review them, and tap Get when you want to download one. The plan is stored on your device and can be opened with Plans on Device.

Browsing and downloading equipment lists works similarly. The screenshot below shows the equipment lists available from the Community. The equipment lists can be sorted by manufacturer or by type [instruments, eyepieces, filters, barlows/reducers, observers, cameras].

Equipment Lists in the Community

You can browse these lists and tap Get to retrieve the equipment list you want. The equipment is stored on your device and may be viewed with Equipment.

14 January 2019

DSP Mobile: Settings

Deep-Sky Planner Mobile Edition (DSPME) provides a Settings screen for displaying and modifying app-wide settings. At the moment, it contains configuration options for the download and display of Digitized Sky Survey (DSS) images, and it contains your selection of the application's display style.

[Screenshots were produced on a 10" iPad using the RegalBlue or BlackRed (nightvision) style.]

DSS Options

DSPME allows you to download DSS images for the objects in your observing plans. When you download DSS images, the size of the image is automatically selected based on the size of the object in the plan. For objects that do not have a size metric (like stars), a default size value can be set.

DSS Settings: Image Size and Invert Colors
You can also choose to invert the colors of the image when it is displayed. The default is white on black; inverted produces black on white.

DSS image of M 31 shown with inverted colors

DSS image of M 31 shown with normal colors
DSS images are served from 2 different websites. If one is unavailable temporarily, you can choose the other.

App Style

Several styles are provided with DSPME. You can choose the one that suits your taste. The BlackRed (nightvision) style is included to help keep your eyes dark-adapted. This style should be used along with brightness settings for your device screen to yield a useful display in a dark environment.

Plan displayed in BlackRed (nightvision) style

07 January 2019

DSP Mobile: Sky Conditions

Deep-Sky Planner Mobile Edition (DSPME) allows you to record the sky conditions when you observe. These conditions - darkness, transparency and seeing - play a role in calculating visibility models for different kinds of objects. The first two metrics are used to determine whether you can see extended object like galaxies, globular clusters and nebulae. The latter is used to predict whether you can split a pair of double stars. Note that these predictions pertain to visual observing, not imaging.

[Note: Screenshot for this post was made on a 7" Android tablet with the Diamond app style.]

Conditions: Darkness, Transparency and Seeing

The various Sky Conditions should be set for each observing session because these metrics change over time. In fact, they change constantly so you may want to change these several times while you observe.

Darkness is entered in magnitudes per square arcsecond  (MPSAS). This value is readily available from Unihedron's Sky Quality Meter. Naked-eye limiting magnitude (NELM) is also shown, and you can use it to estimate MPSAS. Lastly, the Light Pollution Atlas Zone color[1] is displayed for the MPSAS and NELM values These 3 values can be used together to provide an objective assessment of sky darkness to DSPME.

Transparency can be determined objectively from the aerosol optical depth (AOD) at your observing time and place, or you can use the subjective scale. AOD information is available from various services online, including IDEA[2].

Seeing is a well-known metric to double star observers. A value can be entered in a subjective scale which links a description to the Antoniadi and Pickering scales.

These sky conditions are required for some of the visibility models. Once you have entered all the required components (equipment, observer, conditions), you can use the visibility models in DSPME to help predict your observing results.

[1] The New World Atlas of Artificial Sky Brightness, https://cires.colorado.edu/Artificial-light

[2] IDEA (Infusing satellite Data into Environmental air quality Applications) is a NASA - EPA - NOAA partnership, https://www.star.nesdis.noaa.gov/smcd/spb/aq/