Team Lynkeus: Team Log

Event: NASA Space Apps Challenge 2026, Athens Local Event (virtual participation)
Challenge: Dancing with the SARs
Team: Alexandros Liaskos, Stelios Simiakos, Andreas Liaskos
Kept by: Alexandros Liaskos
Last updated: 14 Nov 2026

This log records the decisions and actions of the team, each with its reasons. An entry states what was decided, why, by whom and when. Recording decisions together with their rationale follows the Decision Analysis process of NASA's systems engineering practice (NPR 7123.1D; NASA Systems Engineering Handbook, NASA/SP-2016-6105 Rev 2, Section 6.8, Decision Analysis), reduced to what a three-person team needs.

1. Before the hackathon

ID	Date	Decision or action	Reasons	Decided by
L-01	29 Oct 2026	Alexandros Liaskos decides to take part in the NASA Space Apps Challenge 2026.	A passion for the research subject and for the sciences that NASA pursues. NASA is an organisation the three of us have admired since childhood, and we are glad to take part in an event that it organises.	Alexandros Liaskos
L-02	29 Oct 2026	Alexandros invites Stelios Simiakos and Andreas Liaskos, and both accept. The team is complete with three members.	Of all the people Alexandros knows, these two were the ones who would most want to take part and who were able to. He also chose them for their character and integrity.	Alexandros Liaskos
L-03	3 Nov 2026	The team chooses the challenge "Dancing with the SARs". The challenge is "to build an interactive application that uses radar remote sensing data from the NASA-ISRO Synthetic Aperture Radar (NISAR) mission to track and visualize one or more types of surface change at locations around the world".	The challenge is close to our fields of study (geosciences, geology and natural hazards, geographic information systems), and all three of us are interested in remote sensing and the Earth sciences.	All three
L-04	11 Nov 2026	The team name is Lynkeus (Λυγκεύς). Other names considered: Glaux.	Lynkeus was the lookout of the Argonauts, known for his sharp sight. The name is Ancient Greek and suits remote sensing, which observes from a distance.	All three
L-05	11 Nov 2026	The team image is a star map of the constellation Lynx.	The constellation shares its name with Lynkeus; Johannes Hevelius introduced it in 1687 and named it for its faint stars, which need sharp eyes to be seen. The map is our own work, so it needs no third-party rights: the star positions, brightnesses and colours come from the Yale Bright Star Catalogue (5th revised edition, NASA HEASARC copy) and the boundary from the IAU constellation boundaries. It was designed with Python code.	All three
L-06	12 Nov 2026	The interactive application that the challenge asks for (L-03) will be served at `lynkeus.nkua.cloud`.	The address carries the team name. The domain nkua.cloud belongs to the team lead and already serves his web applications from the same server.	Alexandros Liaskos
L-07	12 Nov 2026	The application works for any area and period that the user chooses.	The challenge asks for an application that tracks surface change "at locations around the world" (L-03).	Alexandros Liaskos
L-08	12 Nov 2026	The application has the interface of a GIS program: a bar at the top with tabs and buttons, dialogs that open for the choices that need more room, and the map always visible in the main area.	The people who analyse surface change already work with GIS programs, so they can use this arrangement without learning a new interface. Because the map stays visible, every choice shows its result at once.	Alexandros Liaskos
L-09	12 Nov 2026	NISAR data are the input of the application, as the challenge requires (L-03). Other inputs may be added as supplementary capabilities.	The challenge allows additions such as other sensors, optical data and GIS layers, and they help to interpret the change that the radar records.	Alexandros Liaskos
L-10	12 Nov 2026	The user reaches the data through their own NASA Earthdata account, with a personal user token.	This is the means that NASA documents for applications outside its own system. The application never receives the user's password, and the user can revoke the token at any time.	Alexandros Liaskos
L-11	12 Nov 2026	The team does not develop new scientific methodologies. The analyses apply established, published methods through official or widely adopted software, and every method, tool and dataset is cited.	Two days are not enough to develop and validate a new method, and offering a method that has not been validated would not be a sound scientific choice.	Alexandros Liaskos
L-12	12 Nov 2026	The application runs on the team's own server (2 processors, 7 GB of memory). Each part runs in its own container, separate from the other sites of the server.	A container holds one part of the application together with everything that part needs, so the application can be moved unchanged to a larger server.	Alexandros Liaskos
L-13	13 Nov 2026	The team will test the application as users on one pilot area.	A US region will be preferable	Alexandros Liaskos
L-14	13 Nov 2026	The application at `lynkeus.nkua.cloud` (L-06) is open to everyone	The challenge asks for an open, user-friendly solution.	Alexandros Liaskos
L-15	13 Nov 2026	The project is named Lynkeus (`lynkeus`), after the team. Its code is released under the Apache License 2.0.	Space Apps asks for an open-source licence and applies the Apache License 2.0 when a team names no other. This licence lets anyone use and change the code, provided that the notices naming the team are kept.	Alexandros Liaskos

2. During the hackathon

ID	Date and time	Decision or action	Reasons	Decided by
L-16	14 Nov 2026, 11:11	Lynkeus is designed as a general platform for the analysis of surface change with NISAR data. What the challenge asks for (L-03) is included in it.	A general platform serves any study of surface change, so it covers the types of change that the challenge names without being limited to them.	Alexandros Liaskos
L-17	14 Nov 2026, 11:11	Lynkeus is built as a final product and not as a prototype. Where NASA has published a standard, Lynkeus follows it; where none exists, it follows the usual scientific convention. The standards are the official names of the NISAR products, the algorithms of the NISAR science team, the data formats approved by NASA's standards office (Cloud Optimized GeoTIFF, STAC), the arrangement of NASA's Harmony services, NASA's open-science and software practices, and the accessibility level of federal websites (WCAG 2.0, Levels A and AA).	We want the platform to be fit for reuse by NASA and by the scientific community. Most of these standards are not binding on a team outside NASA; following them by choice means that nothing in the platform stands in the way of its reuse.	Alexandros Liaskos
L-18	14 Nov 2026, 11:11	The analyses are placed in one tab of the top bar (L-08) and are grouped by what NISAR measures: radar backscatter (GCOV), interferometric coherence (GUNW), surface displacement (GUNW and GOFF) and soil moisture (SME2). Inside every group the tools follow one order: the state on one date, the change between two dates, the series over many dates, and the thematic map from a published algorithm.	These four quantities are the ones that NASA delivers as products, so every phenomenon is covered through its measurement and no tool appears under two names. A grouping by phenomenon would never be complete.	Alexandros Liaskos
L-19	14 Nov 2026, 11:11	A tool enters the application only when it is finished: it has a reference to the published method (L-11), a legend with units, a record of its input files with the program and its version, and a result that agrees with the source program on the same data.	A final product (L-17) needs few tools that are complete, and not many that are partial.	Alexandros Liaskos
L-20	14 Nov 2026, 11:16	The code of Lynkeus (L-15) is kept in a public GitHub repository named `lynkeus`. At the end of the hackathon the submitted version is archived on Zenodo, which gives it a permanent identifier (DOI).	NASA keeps its own related software on GitHub, so that is where its engineers and the scientific community look first. A public repository under version control and a permanent identifier for each release are practices of NASA's open-science policy, which Lynkeus follows (L-17).	Alexandros Liaskos
L-21	14 Nov 2026, 11:29	The code of Lynkeus follows NASA's guidance for software: the PEP 8 style for Python, which NASA's software engineering handbook names, and the conventions of the OPERA algorithm team at the Jet Propulsion Laboratory (automatic style checks, type annotations, documentation of every function, and a test for every function that computes a result). Every input is validated, every warning of a checker counts as an error, and nothing is added that the language already provides.	NASA has no coding standard of its own for Python, so we follow the standard that its handbook names and the conventions that its own teams use (L-17). Code that is small and checked is easier to verify and to reuse.	Alexandros Liaskos
L-22	14 Nov 2026, 11:34	The address `lynkeus.nkua.cloud` (L-06) is set up. A DNS record of type A named `lynkeus`, in the zone of nkua.cloud at Hostinger, points to the team's server (76.13.133.211) with a TTL of 300 seconds.	The record makes the address lead to the server on which the application runs (L-12). A TTL of 300 seconds means that a correction of the record takes effect within five minutes.	Alexandros Liaskos