covid-19 & air quality

mathias
A couple days after attending the EU Space Conference in Brussels end of January 2020, I got sick with fever and mild respiratory and digestive tract symptoms, and additionally, what I remember as the perception of a strange odor or somewhat misled olfaction. Things improved after about a week and I did not spend a though whether this could have been a sars-cov-2 infection (note: later on, I discovered that the first cases officially identified and recorded in Belgium date back to early February 2020 which indeed made it plausible that my infection could have been the real thing). Covid-19 at this time still seemed to be an Asian “problem” with news gradually spreading on infection rates picking up in the Middle East and eventually Southern Europe. As we all know, the situation got increasingly dynamic in March and April with aggravating reports on high death tolls in Iran and Northern Italy. In the evening of April 27 2020, I had a chat with friends from the bio-medical field who had launched into an analysis of molecular mechanisms and patient phenotypes associated with the disease. As a physicist, I had less to contribute from a solely medical point of view, but I had already undertaken own research on data available on environmental factors – specifically those who seem to relate to pulmonary function, which appears most critically targeted by the virus. Although direct pathogenic impact and the complexity of the human immune and inflammatory response seem to be a rich playground for research, I was not ready to give up the idea that environmental factors, notably particulate matter and ground based (tropospheric) ozone, are contributing factors to a deadly course of the disease.

source: EEA Report No 13/2017 “Air quality in Europe – 2017” Section 5.2 (https://www.eea.europa.eu/publications/air-quality-in-europe-2017)

Particulate matter (PM) in ambient air is commonly recognized as an agent that induces lung damage and aggravation of chronic disease, such as asthma. Ozone (O3), which is known to exercise strong oxidative stress on the pulmonary system, not only occurs in a layer high up right below the stratosphere, but also exists as ground level (tropospheric) ozone catalyzed by the influence of UV radiation on volatile organic compounds (VOCs) and NOx/CO co-emitted with particulate matter. The EU commission had just recently published a survey of European air quality and when I looked at the graphics depicting critical PM and O3 levels throughout Europe, together with similar data available for the Middle-East and China, those maps just looked strikingly similar to the ones depicting covid-19 fatality rates. The disaster was already real for Northern Italy, and I got very concerned about Eastern Europe, specifically Poland.

While I have to admit that my considerations regarding covid-19 are far from a rigorous scientific analysis, in the light of the dramatic situation in spring 2020, I decided that scientific gut-feeling and intuition was enough to let some people higher up know that a political connection between environmental protection and handling the pandemic crisis should at least be given a thought.

Consequently on April 28 2020, I sent an email to EU commissioner for climate action Frans Timmermans and the ambassador of the Polish Republic to Germany, Prof. Przylebski:

Email sent to VP Timmermans and Ambassador Przylebski on 28 March 2020.
Note: The link given in the email has changed: https://www.eea.europa.eu/publications/air-quality-in-europe-2017
I was not particularly hopeful that my message would ever be answered, at most expecting perhaps a pre-formatted reply from the commission’s PR department or an envelope with shiny EU stickers.

When I started to forget about it, on 08 April 2020 I received a message with a letter enclosed from the EU Directorate General Environment – ENV.C3:

Dear Dr. Göschl, Thank you for your message to Vice-President Timmermans regarding the correspondence between the expansion of COVID-19 outbreak and some areas with elevated levels of air pollution in the EU, and your specific concerns about Poland. I have been asked to reply on his behalf. […]

Wow ! My trust was restored and I felt honored that the organization was sharing with me, in an elaborate 1+ page letter, their sympathy for my considerations and their political actions, specifically regarding Poland (for confidentiality reasons, I am unable to publish the full content of the communication). I did not receive any reply from the Ambassador of Poland, though.

Eventually, once more uniting communication with creativity and technology, I started to work on my AirStation project.

StratoExplorer: payload for stratospheric balloon

mathias

Having experienced weightlessness on board a parabolic flight, as an (aero)space nerd, I am keeping one big dream for the future:

I would like to witness, with my own eyes, the curverture of the Earth as seen from space

Sadly, I am conscious of the fact that this goal cannot be reached without massive funding or support from outstanding individuals, such as Richard Branson or Elon Musk, that would offer me a ride.

Therefore, I am left with a poor man’s option – nonetheless challenging in nature – to launch a stratospheric balloon to the upper stratosphere at approx ~35km altitude and have my own eyes replaced by panoramic digital imagery. This goal can be reached with creative mechanical and digital engineering, some limited paperwork for air traffic control authorities (I am a pilot already – even excessive paperwork cannot scare me) and a budget roughly 2000 times lower than a ticket on Sir Richard’s Virgin Galactic.

For sure, I’ll get less bang for the buck, but I reckon it will be worth the effort !

This has actually been my entry project into IoT/µC-based digital electronics and of course I discovered that, in order to do this cleanly, I need to research and overcome some fundamental hurdles that led me to initially further other projects

Here are the main requirements and challenges met:

  1. reliable, low-power flight control unit
  2. continuous reception of 3D GPS position data and derivatives
  3. monitoring of inside/outside air temperature in a [-60C, 30C] temperature range
  4. long range (up to 40km) telemetry at reasonable data rates to transmit position and status
  5. panoramic color imagery with onboard storage of image data, possibly even limited downlink caps
  6. trajectory evaluation for landing site prediction
  7. asynchronous, periodic, fail-tolerant execution of onboard tasks

so far, these have been addressed as follows:

  1. while some people chose Raspberry-Pi as an easily maintainable unix platform for flight data management, a Pi’s power consumption and system overhead regarding interrupt handling and bare bones use of digital interfaces, led me to chose the Arduino-type advanced Teensy 3.6 32-Bit ARM Cortex-M4 180 MHz CPU as core for the flight hardware
  2. There is a range of light-weighted GPS devices available and I chose the ublox neo-6M GPS connected to Teensy via a serial interface. It is possible to adjust GPS mode during operations, switching from ground-based ranges of position and velocity to “space”-mode operations.
  3. Two Dallas DS18B20 digital temperature sensors fit to my range requirements and are attached to Teensy via single-wire serial interfaces with phantom power.
  4. Many people used to operate long range telemetry with 434Mhz frequency shift (FSK) modulated RTTY at rates of 50-300 baud and 10mW output. Apart from the transmitting unit being sensitive to temperature induced shifts of the carrier frequency, the receiving part is an adventurous undertaking, using SDR (software defined radio) and TTY decoding software – pretty much as radio amateurs decoding messages from the first generation of satellites. I got it working but it left a fragile impression on me which let me to switch to LoRa digital radio modules. Those are highly reliable, inexpensive, lightweight transceiver units that operate with multi-spectral modulation, sophisticated error-correction and multiple selectable bandwidth and packet length. Eventually I chose HopeRF 868Mhz SX1276 on both ends, an airborne ground plane 1/4 lambda antenna and a custom build (many thanks to Oleksandr from Ukraine !) Yagi antenna connected to the ground receiver. This is hassle free and solid hardware and initial tests inside a building and over a few hundred meters (with obstacles) were successful. A line-of-sight long range test, yet needs to be performed (most likely: Kalmit 49.321N 8.083E – Oberflockenbach/Weinheim 49.502N, 8.723E).
  5. Imagery will use two back-to-back mounted 2MP arducam OV2640 interfacing with Teensy on both Serial + SPI. I plan to rotate the camera assembly using a servo to rapidly step to 3-5 positions within the 180° hemisphere. Image acquisition requires approx 80-100ms per position with memory buffered storage to the Teensy’s SD card (8GB). Unlike other people, I am reluctant to launch expensive and heavy GoPro hardware and renounce to video recording. Moreover, with an amateur budget long range image or video transmission at acceptable bandwidth unfortunately is not feasible.
  6. GPS data is fed into a 120s buffer at 2s time intervals and a 3D linear regression solution is computed using a eigen-vector / matrix decomposition library that flawlessly runs on the Teensy. With the trajectory vector calculated, landing site is calculated from its intersection with the terrestrial plane and data is included in telemetry at payload decent (after helium balloon burst).
  7. One of the existing elements of programming activity is a custom library called myTaskScheduler. It allows to register independent services to be triggered at repetitive absolute (NTP- or GPS-time based) and relative time intervals. Support is provided to automatically process (average, sd, min, max) time series data collected by the registered services. Moreover, myTaskScheduler is able to perform health checks on services and if necessary respond to failures in a defined and reliable manner – without sending the global system into deadlock.

next steps (in a long way still to go …)

  • integrate LoRa and imagery control software with myTaskScheduler
  • wrap myTaskScheduler into a conditional “flight plan” logic to determine activities on launch, ascent, decent, landing.
  • develop software for the hand-held receiver (recovery) unit (LoRa + ESP8266), telemetry aggregation and data display on a dashboard powered by Grafana
  • consolidation of flight hardware on a custom-made PCB (the current wired setup not being reliable enough for field testing)

12th European Space Conference 2020

mathias

New Decade, Global ambitions: Growth, Climate, Security & Defense

Egmont Palace, Brussels. 21-22. Jan 2020.

Those were some cold and foggy winter days in Brussels. I had been successful to get one of the conference tickets as a freelance aerospace party – actually the overwhelming number of participants were executives from the aerospace industry, EU and ESA officials, government bodies from EU countries and journalists.

I felt like little fish – that’s what I was indeed – swimming happily in the sea between the big aerospace tankers. A few month ago, I had resolved to attend this conference in response to my growing interest in the developments of Space 2.0. I wanted to learn from a close distance about the spirit which makes Europe move in this new field – in friendship, but also autonomous from it’s big brothers: US & Russia.

To make it short, those two days by far exceeded my expectations and I returned home very much inspired from this pan-European experience. Within the first minutes of the conference I noticed that the EU had a particular significance to me: My ability to pick up conversations in number of languages other than English – be it German, French or Spanish – helped a great deal to absorb information and interact with the people around me.

I would considering myself a Tech Nerd and of course I was thrilled from the statements of the big industry players with regard to ongoing or upcoming earth exploration missions, the perspective of a lunar or planetary missions or just “physics brought to service“, i.e. orbital platforms for secure quantum-cryptography servicing the EU. The need for environmental monitoring supporting the analysis of ecological damage or the requirement for secured communication are fundamental political questions that reach far beyond the naked interest in technological competition and economic profit.

At the very end of those two days, I very much enjoyed the speech delivered by EU commissioner Thierry Breton (who had to rush back to Brussels from his encounter with US president Trump, just a few hours ago at the Davos WEF). In fact, Breton, who has a long curriculum with technology companies, convincingly presented the European spirit, while cheerfully switching language between French, a few words of German and English.