- Details
TSC is a project initiated about 1.5 years ago out of my frustration with available telescope controllers. My main instrument is a very heavy 13" catadioptric, stationary mounted on a rather large fork mount. The solution I had definitely choked on driving the NEMA 23 steppers with a maximum coil current of 2.8A. Thats where the idea for TSC was born, which is a controller based on a Raspberry Pi Model 3 B and two industrial drivers with a maximum voltage of 30 V and 4A per coil. Soon, the list of desired functions for a controller was defined:
- Full motion control with a wireless handbox and WLAN-based communication with laptops, tablets or smartphones.
- User - defined catalogs for standalone operation of the controller.
- Full access for configuration via graphical user interface.
- Communication with planetarium programs (e. g. KStars or CdC) over the classic LX200 interface via USB or TCP/IP. WLAN connection via SkySafari Pro is also supported.
- Support for LX200 via ASCOM 6.3.
- Support for external autoguiding via ST4.
- Support for standalone autoguiding using INDI as an interface for common guiding cameras.
- Control of DSLRs for single exposures and imaging series including dithering.
- Optional support for up to two additional small focuser steppers.
- Use of a battery-buffered realtime clock and parking to freely available reference positions.
- Support for a temperature sensor.
Many more things are still in the queue, like scaled down driver boards for smaller mounts or GPS support for mobile use. However, TSC operates my telescope now for more than a year and a beta was released recently, which includes the C++ sources, all PCB designs in Fritzing format and Arduino IDE compatible MCU code for the additional microcontrollers. Upon request, an image of the modified Raspian stretch operating system with INDI installed is available so that basic fucntionality can be tested. Links to the github repository can be found under https://tscatm.wordpress.com/.
If you want to get a closer look on the project, a recommended starting point is the user manual: https://tscatm.files.wordpress.com/2018/03/tscuserguide2.pdf
Wolfgang (This email address is being protected from spambots. You need JavaScript enabled to view it.)
- Details
What is Radio Astronomy?
Radio astronomy is a relatively new scientific discipline that employs radio waves to probe astrophysical phenomena from interstellar gas to extragalactic quasars. Since the dawn of radio astronomy in the 1930s, it has played a crucial role in developing our modern understanding of astrophysics. Most famously, the 2.725K cosmic microwave background (CMB) radiation was discovered by Penzias and Wilson at Bell Labs in 1965, using radio telecommunications equipment. Penzias and Wilson soon realized that the pervasive signal they were detecting in their antenna was the faint afterglow of the Big Bang, the very fires of creation. Radio telescopes are also responsible for the discovery of quasars (accreting black holes at the centers of distant galaxies) and pulsars (magnetized neutron stars, the remnants of exploded stars).
Perhaps even more significant than these famous discoveries of rare and exotic celestial objects, radio astronomy allows us to map out the distribution of cold hydrogen gas, the material from which all stars form.
INDI Detectors
INDI is evolving fast, and gives every day a new chance for astronomers and amateurs to give their contribute in knowledge and passion.
Now INDI permits the exploration of the Universe in a wider range of the electromagnetic spectrum, ranging from visible, to infra-red, into the lower radio spectrum.
Some kind of devices, unlike CCDs, permit to observe in the elementary size of resolution: the single pixel. These devices are called by INDI Detectors.
The Detectors are of these kinds:
- Radio Receivers
- Photon Counters
- Spectrometers
- Light Detectors
With the Detectors many field of studies are available for exploration, ranging from:
- Radio observation in both continuum and spectrum
- Tracing light curves in variables and double-stars
- High-speed and Classical photometry
- Exoplanet hunting by spectral drift or occultation methods
- Interferometry
- Sun radio observations
- 3K Cosmic radiation studies
- Pulsars, Quarks, AGNs
- Other kind of studies
The RTL-SDR Receiver
The first Detector being implemented is a software-defined radio based on the Realtek RTL2838 DVB-T dongle. These devices can range from 24MHz up to 2GHz raw reception. When connecting such dongles to satellite dishes Low-Noise-Amplifiers, you can detect many extraterrestrial signals including pulsars. An interferometer can be built using radio astronomy components to achieve this.
SpectraCyber Receiver
The most abundant element in the universe is hydrogen. Hydrogen makes up 75% of the mass of baryonic matter in the universe, followed by helium at 23% , and all other elements at 2%. Due to its abundance, hydrogen has been 
studied thoroughly at its natural harmonic frequency of 1420 Mhz. By studying the kinematics and distributions of hydrogen clouds in the universe, we can gain a better understanding of the history and evolution of our galaxy and the universe overall.
INDI supports Radio Astronomy Supplies' SpectraCyber hydrogen line spectrometer @ 1420Mhz. The 1.42Ghz frequency or the 21cm line is being emitted by hydrogen clouds in the disk of the Milkyway. It supports all the functionality provided by the spectrometer including scanning continuum and spectral channels.
By gathering data from SpectraCyber, not only it is possible to construct contour maps of power densties of the galactic hydrogen distributions, but it is also possible to plot rotational velocities as a function of distance from the galactic center.
AHP Interferometer
The AHP Interferometer is a pulse cross-correlator, that permits up to 16 independent pulse mode inputs.
Each input is then internally cross-correlated with each other line.
The correlator firmware code is applicable to a variety of FPGAs, and it is editable to best suite to the user needs.
Its characteristics are as follows:
- Open Source Verilog firmare code
- up to 16 independent input channels
- cross-correlation on each baseline of the input channels
- delay lines on each cross-correlation baseline and cross-correlation on each delay element
- 32 output switches (2 per channel)
- UART messages with cross-correlation counts and pulse counts of each line for coherence calculation.
The INDI driver uses the CCD class to read the cross-correlations and coherence ratio of each baseline. By snooping a telescope, a GPS one can fill the Fourier plane in realtime and do model comparison, plane transformations in a latter time.
The INDI driver also uses DSP for immediate, in-driver analysis and plane transformations. One can use the single line's tab to enable it, power it when applicable to the hardware, read pulse counts and energy flux/magnitude estimations, obtain the delay line length in meters. Cross correlations are shown into the common Stats tab, and coherence ratios as well. Wavelength and bandwidth are selectable from the main tab.
To start an observing session, the driver needs the position of each line sensor (eye in the sky), the observed object coordinates and the wavelength/bandwidth observed.
This is suitable for both optical and radio observatories.
Also geiger mode revealers are compatible with the AHP interferometer, so cosmic ray observations can be done too.
The source code of the firmware is available here: https://github.com/iliaplatone/interferometer
What's Next?
As we continue to develop the necessary software drivers to support radio astronomy detectors, we also plan to develop front-end clients in applications such as KStars to make radio astronomy accessible to more users across the globe. If you'd like to contribute to this ongoing project, please let us know in the INDI Forums!
- Details
To get MD5sum, open a terminal and type:
md5sum ekos.ova
- Details
INDI development team is happy to announce the release of INDI Library v1.4.1 on Feburary 27th, 2017. This new exciting release builds on the maturity of INDI Library and comes with many new supported devices and fixes for existing drivers. Several improvements and enhancements are included in this release including native support for Cygwin and MacOS platforms in addition to Linux, BSD, and Windows (Client only).
The following is the change log for the release:
- Support for HitecAstro DC Focuser.
- Support for SQL-LE Sky Quality Meter unit.
- Support for USB Focus V3.
- Support for Quantum Filter Wheel.
- Support for 10micron mounts.
- ZWO ASI filter wheel support. Driver updated to latest SDK. Fix infinite loop exposure.
- QHY driver updated to latest SDK.
- Added preliminary support to TCP server connection for all mounts.
- Updated and improved Nexstar Evo driver.
- Fixed reset of filter wheel names to default values under some circumstances
- Fixed feedback loop issue in chained INDI server.
- Handle correctly broken frames in FLI driver; convert time left from ms to seconds as it should be.
- V4L2 CCD driver updated to properly work with DMK cameras.
- Several bugfixes for Moravian CCD driver.
- CCD Simulator allows for up to 4096x4096 resolution.
- Raw color video streaming now uses RGB24 instead of RGBA to conserve bandwidth.
- New Dome and Mount safety interlocks mechanism.
- Fix the Virtuoso mount detection in SkyWatcherMountAPI driver.
- Support relative driver paths to INDI server.
- Fix property cache collision conflict in case of multiple devices per driver.
- Moonlite driver can now sync to any value instead of reset to zero.
- Store OBJECTRA and OBJECTDEC as sexigesimal strings.
- New Axis Lock feature to limit joystick to specific motion axis.
- INDI server now reaps zombie processes as they appear.
- EQMod support for AUX encoder values. ST4 Guide Rates settings. PPEC Switches.
- Fix for TELESCOPE_PIER_SIDE implementation in EQMod driver.
- Several fixes for Pulsar2 driver.
- Fix SER file generation for color frames. Added timestamps for each recorded frame. Support subframed video streams.
- Debug and Logging options can be saved in the config file.
- New CCD_TRANSFER_FORMAT property.
- libindi can now be compiled under MacOS and Cygwin. Non-Linux specific 3rd party drivers are also supported under MacOS and Cygwin.
- When a request for snooped is sent, it is echoed to drivers so that they send the snopped value immediately if it exists.
- libindi shared library (libindi.so) is dropped. libindi now offsers indidriver (shared), indiclient (static), and indiclientqt5 (static) libraries.
- Legacy drivers removed: SkyCommander, Intelliscope, MagellanI, TruTech, SBIG STV
- Details
INDI development team is happy to announce the release of INDI Library v1.5.0 on August 20th, 2017. This new exciting release builds on the maturity of INDI Library and comes with many new supported devices and fixes for existing drivers.
The following is the change log for the release:
- New Detector Interface for photon and radio detectors.
- New Software-Defined-Radio driver (RTLSDR).
- New Connections plugin system to facilitate driver development.
- New standardized tracking properties system for all mounts.
- New Digital Settings Circiles (DSC) driver.
- New Lacerta MGen driver.
- New NightCrawler Focusing Rotator driver.
- New Optec Gemini Focusing Rotater driver.
- New iNovaPLX CCD driver.
- QHY SDK update to 1.10.0. Support for QHY PoleMaster.
- QSI SDK update to 7.6.0
- Support for INDI client under Windows.
- Support for Pier Side in many mount drivers.
- Support for SkySafari.
- Fix FLIUSB for 4.6 and 4.9 kernels.
- Fixed wrong time format in generated SER files.
- ZWO ASI drivers for MacOS.
- Various GPSD fixes.
- Proper handing of ISO8601 timestamps in the generated filenames.
- Improved Gemini mount driver with more functionality and bug fixes.
- Many V4L2 fixes and improvements. Support for V4L2 integer menus.
- Ability to define multiple primary/guide scope configurations.
- ZEQ25 Improvements and fixes.
- NStep driver improvements and fixes.
- Added Ccache support.
- Support for Gotonova driver.
- Added Unity Build support.
- Improved Astrophysics driver.
- Added USB connectivity to SQM device driver.
- More robust handling of reading pier side from mount.
- Warn client that no devices are detected in case of Multiple-Devices-Per-Driver drivers.
- Added PEC control to INDI::Telescope. Each driver must handle the low level protocol to actually enable or disable PEC.
- Added security (hardening) flags.
- SoftPEC implementation for Virtuoso mounts in skywatcherAPIMount.
- Added TELESCOP, OBSERVER, and OBJECT keywords to the FITS header.