DSES Science Meeting, April 27, 2020

Meeting notes by Bill Miller, April 29, 2020.

We had 13 participants in the virtual science meeting:

Dr. Rich Russel, Ray Uberecken, Myron Babcock, Ted Cline, Bob Sayers, Jon Richardson, Jonathan Ayers, John R Kucypeh (sp), Xander Duvall, Tony Bigbee, Ed Corn, Gary Agranat, Bill Miller.

Ray gave a discussion of feed system modifications and plans fix the feed to enable Pulsar work.

Bill said we have to hold a virtual board meeting and elect officers from the board.  We also need to call the annual all members meeting.

Rich gave a presentation with slides (see below) on reduction and graphing of data sets from the  national observatories and Pulsar observations. He also discussed the data from his 9 foot dish and about how to understand the Hubble Galaxy and object classification nomenclature, such as MG0424+0435  where 0424 in the right ascension and +0435 is the declination.  He also discussed the gravitational lensing effect given by the gravity well of a foreground object bending the light  and radio emissions of a background object around it.  Prime examples of this are;  https://www.eso.org/public/images/eso9856f/ and https://en.wikipedia.org/wiki/Einstein_Cross  the Einstein Cross.  Rich gave data and discussion of the Betelgeuse dimming phenomenon and whether this may be preamble to the star going supernova.  While a supernova may be preceded by a few hours by an early warning detector of Neutrinos as Gary has outlined, it is unlikely that this is the cause of the dimming and Rich gave a discussion of his theory and simulation of a passing object shading Betelgeuse.

Xander Duval was in attendance and said that he had been invited to go to the state science fair when others dropped out.  At the Fair he won an award from Nasa on earth science systems and submitted his research paper to the Junior Humanities and Science symposium and scored another award in physical sciences there. We are happy that this worked out well and hope to help him with future work.

Bob Sayers has a 4 ft PVC Mag Loop antenna that he would like to give away.  This can be configured for use with a SuperSID setup.

Rich said that it can be used as part of the Astronomy League’s Silver/Gold certification for radio astronomy.  You need 5 projects, 2 of which you need to build yourself. Available projects are:

  1. SuperSID Monitor
  2. Radio Jupiter or Radio Jove
  3. Neutral Hydrogen (Hi) Measurement
  4. Meteor Scatter
  5. Itty-bitty Telescope

Jonathan Ayers has a paper up on the SARA Western Conference Proceedings.  Gary Agranat says check it out at http://dses.science/wp-content/uploads/2020/04/MitigateRFIinSCDriftScanDataPython.pdf [Python Program for Mitigating Radio Frequency Interference Observed in SpectraCyber Receiver Drift Scan Data Files, by J. Ayres]

Here is a drop box link to the meeting recording missing the first 10 minutes before I logged in.

https://www.dropbox.com/sh/2pqscwj7txr7d5p/AADq0yNlG2KI3ZZDE8lqfxEta?dl=0

These are the slides from our DSES Science Meeting, Monday evening April 27, 2020. Presented by Dr. Rich Russel. In PDF format.

DSES Science Meeting, April 27, 2020

System 1 antenna control system update April 13, 2020

By Glenn Davis

I thought I would put out a System 1 status, so you can see what we’ve been working on the past couple of months.  To quickly summarize:  Lewis Putnam has been concentrating on the System 1 hardware design (Please see the hardware diagram below) to support automatic tracking of the Haswell Mount.  Additionally he has been looking at the individual mount axis characteristics to see how well they can support sidereal tracking (See detail text below). 

Phil Gage has supported myself looking at an Elevation axis movement issue we had seen at the site.  We found a loose cable on our March 1 trip which appeared to be causing the elevation axis issues.  Additionally, Phil has been working on the hardware/software interface for the Labjack hardware (Please see the hardware diagram below).  The Labjack hardware, the U3 and JTick-DAC components, will be used to control the mount axis rates.

I have been updating the System 1 Hardware Simulator to support the Numato Relay Board and Labjack U3/JTick-DAC hardware devices.  Additionally, I’ve been working on the hardware/software interface to the Numato Relay board.  This device will be used to enable the drive controllers and control the direction of the Elevation Axis.  Using the work completed by Phil and the Simulator modifications, I’ve been able to test and debug most of the automatic tracking software modifications and simulate the System 1 tracking celestial objects over large periods of time (hours).    

Here is a more detail summary of the past work and future work on the System 1 team (Before site modifications are performed, we will present our design work to the DSES Engineering Team):

March 12 2020 Trip

  • Purpose: Determine relationship between Az / El drive command voltages and rate resulting from command voltages
  • Approach:
    • Made measurements to calibrate mount Az and El drives (Rate as function of applied voltage)
    • Took measurements separately for Azimuth and Elevation
    • Measured both CW and CCW rates for Az and Up/Down rates for Elevation 
    • Varied voltage via Trailer Control Panel Az and El rate potentiometers from 0 to 5 volts (.2-volt increments for voltages below a volt and 1-volt increments from 1 volt to 5 volts.)
    • Logged axis position data in System 1 software
    • Captured measurements in Excel spreadsheet and plotted
  • Findings:
    • Plotted results indicate linear relationship between voltage and rate for both positive and negative rates for both axes.
    • Performed linear fit to determine slope and intercept values that can be used to convert an axis rate into a command voltage.
    • Unique Slope and intercept parameters will be used in System 1 software
    • Slowest drive rates are .02 deg/sec for Az and .06 deg/sec for Elevation; lowest rates were consistent between positive and negative rates
      • Rates needed for sidereal track are about an order of magnitude lower
      • Will have to cycle axis drives on / off to achieve sidereal track rates
    • Elevation Potentiometer voltage will not go to zero
      • Lowest voltage is somewhat less than .2 volts
      • Cause is unknown but potentiometer is most likely candidate
    • Measurements for Elevation similar to results from August 2019 but measurements for Az significantly different from August results, unknown cause
    • Measurements in March were more extensive and disciplined. Will use calibration from these measurements in the implementation of the software.

System 1 Mount Drive Interface Hardware Design/Implementation

  • Progress:
    • Completed hardware circuit design
      • Interfaces to the tower drive electronics via the Jones Plug
      • Uses a Labjack U3 device / TickDAC that provides two +-10-volt Digital Analog Convertors to enable setting Az / El axes control voltages
        • Labjack has necessary digital I/O to interface to the axes encoders so downstream can be used to replace the now obsolete Integrity Systems digital I/O board
      • Uses Numato 8 Relay Board to enable the drive controllers and control direction in the Elevation Axis
    • Developed an approach to integrating circuit into the trailer rack
      • Mount components on a small rack shelf about 6” deep
      • Mount shelf on back rails of the Trailer Rack
      • Move Jones cable from Manual control panel to System 1 Drive Control when using System 1 for drive control
    • Acquired major components and some minor components – Numato 8 Relay Board, Labjack interface device, Jones plug and wire
  • Next Steps:
    • Colorado Springs
      • Acquire remaining additional components – Switch, LEDs, resistors, rack shelf/panel
      • Mount components on rack shelf and wire components together
      • Integrate / test software with drive control assembly
    • Site
      • Install rack shelf / panel
      • Install updated software
      • Test / debug automated drive control

Please pass this on to other individuals who may be interested.

Thank you.
Glenn Davis