DSO Image

Figure 15: DSO Image screen
Image dsoimage

This module shows object images (Figure 15). There is an internal image database that has an image for almost any Ngc object (7840 images). You could also add any number of images for your own user database objects:

This module could be called from context menu of Observations Lists, Object Selection and View Database, and by Image button from Details Screen.

If there are several images for an object you could change them by flicking up the current image. Use pinch to zoom gesture to change image scale.

Global Search

Figure 16: Global Search screen (night mode)
Image globalsearch

''Global Search'' looks for specified string in all application object databases (in name fields), in note database (in name and content fields) and in star chart layers (in name fields)12. This function (Figure 16) could be called from any place by pressing Find button if it is present on the device, or via Object Selection, Observations Lists or Star Chart Menus.

Search examples:

User Horizon text format

Figure 17: User horizon
Image user_hor     

To draw your local horizon on Star Chart you need to prepare a text file where each line contains Az Alt pair. For example, Figure (17) shows a user horizon for the following data:

19 0

20 10

30 30

40 60

60 60

61 0

DSO Planner text format

Each object is represented by a text string which starts with ''& '' symbol and then contains pairs of the form ''field=value'' separated by '';'' symbol. The pairs could be put into a text string in any order. It is possible to use only some fields and omit other, in this case omitted fields will be automatically set to 0 or zero string. To deal with several objects at once place several lines into the text file, every line corresponding to its own object.

If you need to use ''& '' or '';'' within value (e.g. within text fields), just put ''\\'' before the symbol: ''\\&'' or ''\\;''.

Standard object fields

Additional (custom) object fields

If standard object fields are not sufficient for object description one could use any number of additional fields. Additional fields could have the following types:

Auxiliary fields

When exporting/importing the application uses several auxiliary fields for database reference, note description, location description, etc; users should not use these fields for their object description (''note'', ''notebaseid'', ''date'', ''time'', ''path'' , ''latitude'', ''longitude'', ''aperture'', ''afov'', ''catalog'', ''id'', ''selected'', etc.).

Useful abbreviations


Double star from WDS (Washington double star) catalog: $\&name1=00000+7530;name2=00000+7530;ra=0.001844;dec=75.483276;mag=10.27000;pa=235;type=ds;year=1982;components=;mag2=11.50000;spectrum=;separation=0.600001$

This double star description uses the following additional fields14:

Dark nebula from Lynds catalog: $\&name1=LDN1;name2=LDN1;ra=16.480963;dec=-16.107859;opacity=3;a=13.942740;b=13.942740;type=neb$

Bright nebula from Lynds catalog: $\&name1=LBN1;name2=LBN1;ra=17.752939;dec=-28.851336;brightness=5;a=4;b=4;type=neb$


The program extensively supports import/export operations in DSO Planner text format. Any list with objects, notes, locations, telescopes and eyepieces could be exported in text format and imported back.

Temporary/Permanent Objects

Objects could be permanent and temporary Temporary objects are created much easier. They are required if you need to see something quickly and you do not care whether they will exist later. Temporary objects are also required for exchanging observation lists among users. Temporary objects has less functionality than permanent.

Permanent objects could be used in Object Selection filtering. Permanent objects are included into Global Search.

Temporary object exists until it is removed from the observation list. Temporary object is not included into Global Search, however it is still included into Find/Next search.

When importing external list into observation list (from other users) it is temporary objects (with limited functionality) that are created, with the only exception of internal database objects15. This is understandable as every user may have its own database structure and its own object location within it. Therefore, other user objects could not be referred to your own databases.

This issue could be partly solved by creating a new user database and importing objects into it. However, before importing you need to create a database with exactly the same additional fields as used in object lists, otherwise information in additional fields will be lost. This may not be a solution when an external observational list that you import contain objects from various user databases.


This is a simple search of a string within the object name in a current list only. ''Find'' looks for the first coincidence, ''Next'' for all others. The positive search result is shown in bold. The search is inclusive (e.g. ''12'' is found in ''abc12'' name). To reset the search just press ''Find''.


DSO Planner supports 2 simple gestures. Flick Up at the bottom - to call the main menu of the window, and flick left to simplify returning to the previous window, or to close the dialog window (similar to "Back" button of Android). However the gesture will not work over such active GUI controls as buttons, list and edit fields.


Figure 18: Dobsonian telescope with simple setting circles; One star alignment dialog
Image dob1      Image dob2      Image dob3      Image onestaralign

The application could calculate setting circles readings for telescopes with Alt-Az mount. There is no need to align setting circles so that zero azimuth points exactly to the North, and zero altitude is exactly at horizon. It is sufficient to level the telescope base in horizontal plane16 and perform one star alignment. Telescope base should be in horizontal plane for correct calculation of setting circles azimuthal reading.

Application author uses Dobsonian telescope for observations (Figure 18). Azimuthal circles glued to mount base have a 0.5 degree step. Altitude circles are represented by a cheap digital inclinometer with 0.1 degree accuracy. In practice with a help of the application such an equipment permits to find almost any object during 1-2 minutes.

To perform one star alignment you need to go to Star Chart and select an alignment star. Then point your telescope to this star and select Align Star from Star Chart Menu. Make sure that the star is seen exactly at eyepiece center and fix the time of this occasion by pressing Now button (Figure 18). Then enter azimuth and altitude readings of your setting circles into Measured Az and Measured Alt fields and press One Star Align button. The application will calculate necessary adjustments for setting circles.

ClockWise and CounterClockWise buttons allow to select the azimuthal setting circle direction.

Later you could see azimuth and altitude values of any object recalculated for setting circles at the left bottom side of star chart control and information zone by turning on Show Adjusted Az/Alt.

Object Types

The following object types are used throughout the program:


Object visibility is measured on 0-5 scale,where 0 is invisible and 5 bright. Visibility depends on object brightness and dimensions, sky condition (its limiting magnitude - the magnitude of the faintest star one could see at zenith), telescope aperture, its passthrough and magnification (that is an eyepiece used with the telescope). Blackwell model is used for visibility calculations.

Visibility is not calculated for comets and objects with absent magnitude or dimension. For such objects visibility is considered a missing parameter. Set Empty field treatment as you need to include / exclude such objects when filtering them in Object Selection.

As an exception if dimension is missing in planetary nebula, minor planet, or double star its visibility is calculated as that of a star (point-like lighting source).

Detection limit is a minimum visibility threshold: when using visibility filter to look for objects only objects with visibility above or equal to the detection limit are found.

Bluetooth GoTo

Figure 19: GoTo Mount Setup. Details GoTo button (bright theme)

     Image gotomountsetup      Image detailsgoto

This module allows to communicate with telescope via bluetooth dongle (to be acquired separately). At the moment the program supports two telescope types: Celestron and Meade. It is planned to increase the number of supported telescopes.

To connect to your telescope you need first to pair with it via standard Android settings and turn bluetooth on. Then go to ''GoTo Mount Setup'' screen either via Settings or Star Chart Menu (Scope go). There you could set up communication with your telescope.

''GoTo Mount Setup'' screen functions (Figure 19):

After connection is set you could


... file11
just make sure that you have the image files on SD card at the paths that you specified. The path form depends on each particular device, first try to add the image manually to see what form the path takes. Usually it is ''/mnt/sdcard/some directory/file''
... fields)12
except for USNO UCAC4. The reason is that the index file required for fast search would be too large, but the search without such a file is very slow
... type13
e.g. using custom object type you could assign a ''meteor'' type to your object
... fields14
which were set when database was created
... objects15
i.e. when internal database objects from other user list are imported they are created permanent
... plane16
e.g. with the use of a simple level device