You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 20 Next »

Use case

(Updated Aug 2017 with Aladin v9.6, SE)

Use case by Sébastien Derrière, CDS (June 2015), enlarged with comments and implementation notes

Summary : Build a 3D spherical HiPS off Io, and overplot surface features from USG catalogue.
This is an extension of Use Case #28 of Aladin Beta Test page (requires Aladin v9 and up):

• Planetary maps are available, for example from here:
or here

In this example, we work with Io:

• extract io_bjj_0dd.tif, convert to jpg

In the terminal, type:
    > convert io_bjj_0dd.tif io_bjj_0dd.jpg

• Load jpg image in Aladin as local file
Image size is 2880 x 1440
Set Frame drop menu (next to Location field) to Planet

• Apply astrometric solution:
Image > Astrometrical calibration
Use parameters:
Central pixel 1440.0 720.0
Pixel angular size = 7.5' (= 360/2880*60)
Projection = CARTESIAN
Rotation = 0°
RA symmetry: False

• Convert to HiPS :
Tool > Convert current image to a HiPS
Apply grid, pan around, zoom in/out ...
    > Type Comm-G to overplot coordinate grid
    > Beware that  longitudes are handled as Righ Ascensions (inverted)

• Adding catalogue:
Planetary nomenclature downloaded from
Extract nomenclature_all_feb2004.dbf
convert to csv with

Little cleanup of csv file, and load it in TOPCAT.
    > Remove EOL character <NULL> in TextMate or another handy editor

• Filter Io features only by creating subset (io, expression SA=="io")
-> 221 lines out of 8395 in io subset
    > Click on red/violet icon, add a filter
    & "plot subset" io in main window

Choose io Row subset in main TOPCAT window and broadcast to Aladin via SAMP

• Right-click catalogue plane in Aladin, Column Information
Click on Coord for LATITUDE and LONG360, pretending they are DEC and RA, respectively.

• Create dedicated filter :
In advanced mode, use the following expression :
    > this is Catalogue menu item / create new filter / advanced mode

# scale is 113.3 arcsec/km
draw ellipse(113.3*${DIAM}, 113.3*${DIAM}, 0) rainbow(${AD},1979,2003)
draw ${NAME} rainbow(${AD},1979,2003)
Displays names and sizes of surface features, color-coded by year of discovery.

• Remaining issues :
Defaut orientation of RA or longitudes in Aladin is different
from the one used in planetary science, therefore the surface
is viewed as from within the planetary body, not from outside.

> Other pb on my side :
- long180GIS does not work either?  

- Filters are not saved ?

- Graphic mix up when ploting 2 views simultaneously

Comment: healpix only supports spherical projections, not ellipsoids

Extension to Mars use case

• Mars IRTM albedo (Viking):
convert alb_.09.tif alb_.09.jpg

resolution = 1°/pixel
size= 2 * pi * R / nb pix = pi * 3390. *2 / 360. = 59.2'

Can be enlarged to 60' ?

Feb 2016, Aladin 9


Aladin 9 / java 1.6 / Mac OS: often blocking at launch, but not always

Mars image is now OK

"Save image" does not include the projected image (only the sphere frame)!


Application by Mikhail Minin with Aladin Lite:

I guess we would like very much to have a Long/Lat option to plot the coordinates (in addition to J2000 and GAL).

E Long are the basic option.


Message from Pierre Fernique 10/3/2016

(copied from VESPA Slack:

the method described by Sebastien Derriere can already be improved a little bit like this:
1) put one or several images of the planet (jpg or png) in a folder (yourFolder)
2) for each file, you will associate a xxx.hhh calibration file (same prefix name but .hhh extension). These calibration files will contain the WCS header (*)
3) use Aladin/Hipsgen with this syntax: java -jar Aladin.jar -hipsgen in=yourFolder color=true
4) your HiPS will be generated in yourFolderHiPS directory that you can load directly in Aladin, and/or publish on your apache HTTP server.
With this method, your will be able to create and publish deep HiPS (at any resolution) rather that just a low resolution planet map. Notice that you can already display your HiPS in various projections (SINUS, AITOFF, MOLLWEIDE, AITOFF, CAR, ...) via the Propertie button in Aladin.
I will keep you inform of our progress in the Aladin code (inversion of longitude, ellipsoide projection...). Do not hesitate to signal the various problem that you see
(*) The WCS header is presently sky oriented and you will have to adapt WCS to your image collection. For instance, if you take this unique image (the earth in cartesian projection), you may use this following calibration file
NAXIS1  = 2048
NAXIS2  = 1024
CRPIX1  = 1024.0
CRPIX2  = 512.0
EQUINOX = 2000.0
CRVAL1  = 0.0
CRVAL2  = 0.0
CD1_1   = -0.185546875
CD1_2   = -0.0



  • No labels