Further to earlier post:-

Re-installing the mutlaqja repository cures the problem. The error was somehow associated with the previous apt-add-repository although the repository information was correct i.e. identical to the information on another computer where apt update and install worked.

Sorry if I wasted anyone's time.


I too am having problems downloading and installing indi/kstars. I hav eadded the mutlaqja repository but when I attempt:

sudo apt-get update I get the following response and a refusal to download any files. I'm using Linux Mint 20.

W: GPG error: ppa.launchpad.net/mutlaqja/ppa/ubuntu focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 487CEC2B3F33A288
E: The repository 'ppa.launchpad.net/mutlaqja/ppa/ubuntu focal InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Help would be gratefully received.


Further information as an aid to diagnosis.

I ran INDI/Ekos with the telescope simulator and the ccd simulator. The ccd simulator has a field of view 133' by 107'. After picking an arbitrary point on the star map (RA 12:26:31 DE 69:41:47)and starting tracking I invoked "Capture & Solve" under the Ekos align tab. This produced an error message saying "index files index-4205 to index-4211 are missing" and the solver failed to work. When I used the ccd simulator (so same field of view)to take an image of the sky and then invoked "Load & Slew" under the Ekos align tab the solver worked fine and slewed the telescope to the appropriate co-ords. When I used "Load & Slew" with an image of the region around M31 I had taken some time ago the solver also worked and the simulated telescope slewed to M31 on the star map. My image was taken with a QHY5Lii on a 130mm focal length telescope and thus had a field of view 128' by 96' - almost the same as the ccd simulator and requiring the same astrometry files for solving.

The problem, therefore, appears to be with the "Capture and Solve" procedure rather than with the use of the astrometry files generally.


My camera field of view is approx 19.6 arcmin by 12.4 arcmin. I'm using a C8 with an f6.3 focal reducer which gives a focal length of 1280mm. The camera chip is 7.3mm by 4.6mm.

(I misquoted the field of view in my original post and gave the smaller field of view for a QHY5LII.)


I am running kstars/ekos on a RPi3B+ connected to an HEQ5 Pro and an ASI185 colour camera. The field of view of my camera, attached to a celestron C8 with an f6.3 focal reducer, is approx 13'x10'. I am trying to use the ekos align module offline on my laptop and it consistently fails to solve. I get an error message saying that the index files 4200 to 4204 are missing. The files are actually present in the /usr/share/astrometry directory on my laptop (and on the RPi) and can be read with ghex. They are shown as present when I open the directory via the index files option in the align module. My astrometry.cfg file in /etc shows "add_path usr/share/astrometry" and "autoindex". The "autoindex" fails for files 4200 to 4204 but apparently works for any of 4205 to 4219 it may require. It is not clear to me, given the specified field of view of my camera, whether the 4205 files are required. None of 4206 to 4219 should be. All of my index files are owned by root but all users have read access.

The mount control features using the control panel and the track function from the kstars star map seem to work fine.

I would be grateful for any help in resolving my difficulties.


I have newly installed indi-full and kstars-bleeding on a RPi3B with Ubuntu Mate. When I start KStars and "Run Service" the telescope simulator in Device Manager I do not get the INDI Control Panel. Two other installations of the software on a desktop and a laptop (both running Linux Mint Mate) produce the Control Panel.

I have updated and upgraded INDI/KStars and this has had no effect.

Can anyone suggest where or how I may have gone wrong? I can find no reference to similar faults on the forum. In case it is relevant - I have checked and found that I am a member of the dialout group on the RPi.