u/DeepSpace1420MHZ

Primary Antenna System
• 4.5 meter prime-focus mesh dish
• Daily survey elevation:
o 58° EL
• Weekly stepped azimuth drift survey:
o Typically, 2° AZ increments
• Location:
o Grid EN61vq
o Approx. 41.66° N, 86.16° W
Feed and RF Front End
Feed
• VE4MA linear polarization hydrogen line feed
RF Chain
VE4MA feed
Down East Microwave 1420 MHz LNA + SAW filter
o Approximate NF:
▪ 0.35 dB
o Gain:
▪ ~18 dB
DEMI 10 dB gain block
LMR-400 coax feedline
Estimated system characteristics:
• Dish gain:
o ~34 dBi
• System temperature:
o ~155 K
Receiver System
Primary SDR
• SDRplay RSP1A
o 12-bit SDR
o Used for all current hydrogen observations
Software
• HDSDR
• Spectrum Lab
o Real-time spectrum display
• SpectraVue RMS
o Daily and 24-hour recording
Dish Control System
Tracking Software
• F1EHN EME System software
Controller Hardware
• VE1ALQ interface hardware
• RS-232 motor control
• Sipex RS-232 boards
Position Feedback
• Pendulum elevation encoder
• Motor/transmission with AZ encoder
Capabilities
• Sun tracking
• Moon tracking
• General astronomical tracking
• Manual AZ/EL positioning
• Daily hydrogen drift survey positioning

Observatory Computing Architecture
PC #1 — Dish Control Computer
Purpose:
• Runs F1EHN EME software
• Controls dish movement
• Communicates with motor controllers via RS-232
Responsibilities:
• AZ motor control
• EL actuator control
• Position tracking
• Coordinate calculations

PC #2 — Live Receiver / Streaming Computer
Software:
• HDSDR
• Spectrum Lab
• OBS Studio
Responsibilities:
• Operates the SDR
• Generates live spectrum displays
• Produces livestream output
• Sends receiver audio to distribution amplifier
Outputs:
• YouTube livestream
• Daily drift audio feed
• 24-hour scan audio feed

Audio Distribution System
Hardware:
• Small audio amplifier/splitter
Purpose:
• Splits receiver audio to multiple recording systems simultaneously
Feeds:
• Daily drift recorder
• 24-hour recorder

PC #3 — Daily Drift Survey Computer
Purpose:
• Records daily hydrogen drift scans
Products:
• Daily CSV recordings
• Daily drift plots
• Daily processed observations
• Weekly stepped sky survey data

PC #4 — 24-Hour Survey Computer
Software:
• SpectraVue
Purpose:
• Performs continuous 24-hour hydrogen recordings
Configuration:
• One spectrum every 2 minutes
• FFT size:
o 16384
• Approximately:
o 720 spectra/day
Products:
• 24-hour WAV recordings

External SSD Transfer System
Purpose:
• Physical transport of large datasets
Workflow:
• PC #4 → External SSD
• External SSD → Processing workstation

PC #5 — Processing Workstation
Purpose:
• Large-scale data processing
• Rendering
• Visualization
Products:
• 24 hour drift processing
• Polar hydrogen maps
• Velocity ridge plots
• Velocity curtain plots
• RA/Dec projections
• 3D hydrogen terrain renderings
• FITS generation
• DS9 visualization products
• Animations/videos

Observatory Storage System
Local Archive Rack
Purpose:
• Long-term storage
Contains:
• CSV data archives
• Daily drift scans
• 24-hour observations
• Plot archives
• Render outputs
• 3D products
• Processed datasets
Capacity:
• Multiple terabytes

Cloud Archive
Google Drive
Purpose:
• Public sharing
• Remote access
• Backup
Shared products:
• CSV files
• Drift plots
• Polar plots
• 3D renderings
• Processed observation products

Public Outreach System
YouTube Livestream
Running:
• 24/7
Displays:
• Live receiver spectrum
• Links to daily observations
• System status

Current Survey Programs
Daily Hydrogen Survey
• Elevation:
o 58°
• Duration:
o 180 minutes
• Weekly:
o 2° AZ step
24-Hour Hydrogen Survey
• Duration:
o 24 hours
• FFT:
o 16384
• Sample interval:
o 2 minutes

Current Observatory Scale
• 1 radio telescope
• 5 dedicated computers
• RS-232 motion control
• Dedicated audio distribution system
• External SSD transport workflow
• Multi-terabyte archive rack
• Cloud data sharing
• 24/7 livestream
• Daily and 24-hour hydrogen survey programs
• Advanced post-processing and 3D visualization pipeline

Hydrogen line continuum survey from daily drift scans is complete now, from scans to HI 3D cloud rendering and then to the RA DEC location.

3D Hydrogen Line Radio Terrain 1420 MHz 24-Hour Multi-AZ Survey. Peak HI Surface + Top-Down Projection

3D radio Terrain HTML rotatable model viewable on a PC, picture posted as a reference. 11 azimuths, 2 degrees apart, 69 to 89, 24-hour spectral FFT survey plotted in Python with Plotly. HTML link posted in the body

Neutral Hydrogen (1420 MHz) RA Comparison from Six Consecutive Daily Surveys at -7 Declination (very low at my location)

Sun noise check at 11:17am EDT was a quick +10db confirmation that things are working good. This was not measured from coldest sky or calculating today’s SFI. Just a quick remote log in to confirm sensitivity.

Behind My 1420 MHz Plots. A simplified overview. Individual 180-minute drift scans are stacked to build the 3D hydrogen model. Since each scan covers only a small portion of a 24-hour observation, full-day observations are processed separately into radio terrain and full-sky visualizations.

1420 MHZ Radio Telescope Systems Basics

Here is the corrupted HI Drift Scan with lightening spikes due to the thunderstorm. Can easily see the lightening as seen in the earlier posted video.

Daily live HI Drift Scan corrupted by Thunderstorm

3D HI Cloud Rendering currently, adding more AZ each week. Currently 65-81 AZ at 58EL from EN61vq

3D HI rendering currently, adding more AZ each week

Independent detections of the same HI-rich region on separate dates using two different observing methods. A daily 1420 MHz galactic drift scan and a separate 24-hour spectral survey both pointed to the same sky region near RA 20h30m.

Five 24-hour hydrogen-line observations from EN61vq combined into a 3D neutral hydrogen map of the Milky Way.(58° EL, AZ 69°–77°) A rotatable HTML file is in the shared file link found in the live chat.

Hydrogen Survey, with weeks to go yet is taking on shape. The RA/Dec location map and other plots with csv scans are shared on the livestream chat

24hr Spectral scan finished yesterday, AZ77 EL58 from EN61vq.

Spectral galaxy scan of 69AZ 58EL compared to 75AZ. We had storms and I think the polar map may show nearby lightening. Either way, here’s the two.

24-Hour Milky Way HI Survey (1420 MHz) — Hydrogen Intensity & Velocity Maps. Ran at 69AZ 58EL from Lat 41.66N / Lon 86.16W. The next 24hr spectral is planned for 83AZ 58EL with a wider band width.

24 hour Spectral Scan running live now. Hopefully will have good data to share within a week or so. Will resume the drift survey after. 65AZ 58EL from EN61vq

May Survey Observation: Using the optimized 4.5 m dish (34 dB gain), we scanned the Cygnus outer-arm region shown on the sky map. One hydrogen peak has been mapped; we are now moving north in search of another. A 24-hour spectral scan is planned for June.