AEIC Requirements Specification
Version: 0.2 Date: 2025-08-12
| Name | Narrative | Key needs |
|---|---|---|
| Aircraft emission analysis | Calculate emissions from a candidate aircraft flying a set of prescribed missions. Often missions are chosen to replace part or all of an existing fleet in order to quantify its emissions. | Loading OAG schedules for years, filtering them for a specific aircraft type or maximum range. Having detailed emissions outputs for AEIC run. |
| Aircraft Design | Run an annual global schedule multiple times with different performance models in order to analyse and trace emission impacts against design choices. | Import performance models from external tools, run schedule at scale. Be able to save schedule/trajectories and run with different performance model. |
| Fast aircraft optimization | Run a small schedule sampled from the annual OAG data multiple times with different performance models to use outputs of AEIC in objective functions within an optimization loop. | Import performance models from external tools, run sampled schedule. Be able to save appropriate vertically optimized trajectories and run with different performance model. |
| Seasonal environmental impact | Capture seasonal impacts by selecting sample of missions across the year (for eg. every 8th day in the year) | AEIC input must be missions sampled from OAG/SQL database and the run the normal pipeline |
| Full fleet annual environmental impact | Generate outputs (e.g., gridded emissions) compatible GEOS‑Chem or ACAI so aviation emissions can be translated into climate/AQ impacts. | AEIC will output trajectory level information in a SQLite database that can be processed to get GEOS-Chem/ACAI suitable inputs. Standard gridding tools will be used. Grid definitions etc. will be defined in some config/ overlay files |
| "Filtered fleet" environmental impact | Calculate trajectory level emissions for a filtered fleet of aircraft types/ engine types/ flights/ regions of operation/ altitudes of operations. "Full fleet" analysis outputs in SQLite database if already run can be filtered and processed | No additional needs apart from above |
| "Parallel universe" fleet impacts | Calculate emissions inventory (a trajectory level SQLite database) for a slate of "what-if" analyses -- e.g., what if twin aisles where possible were replaced with A321XLRs; what if all single-aisles were updated to latest aircraft/ engine types; what if flights over a threshold distance had a hop... | Input files/ pre-processing system to define "replacement mappings" with logic to hold appropriate quantities constant (ASK? RPK? payload? frequency of departures?) and make required calculations; Logic to only run the affected missions and combine with existing (i.e., from a "normal" full fleet run) inventory database? |
| "As-flown" fleet impacts | Emissions inventory for a fleet using as flown trajectories from ADS-B data | Take in ADS-B data (using feder?); functions to calculate emissions/ fuel burn on the ADS-B trajectory |
| Emission metrics analysis | Apply alternative emission metric/algorithms to a fixed set of trajectories in order to compare methodologies. | Caching trajectories and running different emissions modules to it |
| AEIC Developer | Comprehensive logging and a cache layer such that results are reproducible and debugging is easy. | Structured logs, cache directory API |
The following numbered technical requirements (TR‑IDs) derive directly from the user stories in Section 1. Each requirement is expressed in “shall” form and marked [H]igh or [M]edium priority.
| ID | Requirement | Priority |
|---|---|---|
| TR‑SCH‑1 | The module shall ingest OAG schedules in SQL format, process them to get aircraft type, load factor, datetime and airport pair. | H |
| TR‑SCH‑2 | The module shall allow filtering schedules by date range, airline, aircraft type, and route distance or maximum range. | H |
| TR‑SCH‑3 | The module should persist filtered schedule subsets to avoid recomputation in later runs. | M |
| ID | Requirement | Priority |
|---|---|---|
| TR‑PERF‑1 | The system shall accept performance models input as a TOML file defining fuel flow at different points specified by altitude, rate of climb/descent, mass, airspeed. | H |
| TR‑PERF‑2 | The system should support batch execution across a schedule using multiple performance models. | M |
| ID | Requirement | Priority |
|---|---|---|
| TR‑EDB‑1 | The system shall accept an emissions databank (EDB) excel file as well as an engine UID in order to get LTO data points. | H |
| TR‑EDB‑2 | The system shall also accept custom LTO data points within the performance model if the EDB is not needed to be used. | H |
| ID | Requirement | Priority |
|---|---|---|
| TR‑TRAJ‑1 | The trajectory module shall produce 4‑D trajectories (lat, lon, alt, time elapsed) for every flight in the mission. | H |
| TR‑TRAJ‑1 | The trajectory module shall metrics such as fuel flow, aircraft mass, etc. at each point in the trajectory | H |
| TR‑TRAJ‑2 | The module shall cache trajectories keyed on aircraft type, airport pair, etc. | M |
| ID | Requirement | Priority |
|---|---|---|
| TR‑EMI‑1 | The emissions module shall compute emission indices and emissions in grams for |
H |
| TR‑EMI‑2 | The module should support multiple algorithm variants (e.g., P3T3, BFFM2 for |
H |
| TR‑EMI‑3 | The module shall aggregate emissions per flight, per aircraft type, and globally per species. | H |
| ID | Requirement | Priority |
|---|---|---|
| TR‑PPM‑1 | The post processing module shall grid emissions at user‑defined spatial resolution and temporal resolution (hourly). | H |
| TR‑PPM‑2 | The module shall output NetCDF files with species names and units conforming to GEOS‑Chem & ACAI requirements. | M |
| TR‑PPM‑3 | The module shall include helper scripts to stage data for GEOS‑Chem, ACAI, etc. | M |
| ID | Requirement | Priority |
|---|---|---|
| TR‑LOG‑1 | All components shall emit structured logs with timestamp, run UUID and flight IDs where relevant. | M |
| TR‑LOG‑2 | Each run shall print a configuration snapshot, and summarized outputs of trajectory and emissions modules. | M |
| TR‑LOG‑3 | The system should capture runtime metrics and profiling for performance tuning. | M |
| ID | Requirement | Priority |
|---|---|---|
| TR‑DOC‑1 | AEIC shall include proper documentation, user guides and example scripts covering each user story. | M |
| TR‑DOC‑2 | Automated tests shall achieve ≥ 80 % code coverage, with a full test for a small schedule. | M |
| Source | Format | Mandatory? | Key Fields / Sections |
|---|---|---|---|
| Performance model file |
TOML data/PerformanceModel/*.toml
|
✔ |
General_Information, Speeds, LTO_performance, flight_performance
|
| Missions / OAG Schedule | SQL | ✔ |
dep_airport, arr_airport, dep_datetime, arr_datetime, great_circle_distance?, ac_code, load_factor?
|
| Airports database | SQL | ✔ |
iata_code, lat, lon, altitude
|
| Configuration File |
TOML (default_config.toml) |
✔ |
General Information, LTO data, Missions, Emissions, Output
|
| Weather data (ERA‑5, MERRA‑2 …) |
NetCDF‑4 | ✖ (falls back to standard atmosphere) | Winds: u, v, relative_humidity
|
? means the field is optional
For each mission a Ntot‑length (total number of mission points) table trajectory_<FLIGHT_ID> is saved with columns:
| Column name | Description | Shape |
|---|---|---|
fuelFlow |
Total fuel flow rate [kg/s] |
(Ntot,) |
acMass |
Total mass of aircraft over the trajectory [kg] |
(Ntot,) |
fuelMass |
Mass of fuel over the trajectory [kg] |
(Ntot,) |
groundDist |
Cumulative ground distance covered [m] |
(Ntot,) |
altitude |
Altitude [m] |
(Ntot,) |
flightLevel |
Altitude in flight levels [ ] | (Ntot,) |
climbRate |
Rate of climb (negative for rate of descent) [m/s] |
(Ntot,) |
flightTime |
Elapsed flight time [s] |
(Ntot,) |
latitude |
Latitude at mission point [degrees] |
(Ntot,) |
longitude |
Longitude at mission point [degrees] |
(Ntot,) |
azimuth |
Azimuth to arrival airport [degrees] between the current heading and the arrival airport |
(Ntot,) |
heading |
Heading at mission point [degrees] |
(Ntot,) |
trueAirSpeed |
True airspeed [m/s] |
(Ntot,) |
groundSpeed |
Ground speed [m/s] |
(Ntot,) |
FL_weight |
weighting used in linear interpolation over flight levels [ ] | (Ntot,) |
The trajectory table is extended in‑place with:
| Field | Unit |
|---|---|
wind_u, wind_v
|
m s⁻¹ |
relative_humidity |
For each mission the module stores emissions_<FLIGHT_ID> containing:
| Column name | Description | Shape |
|---|---|---|
emission_indices |
EI by species at each point in trajectory | (Ntot, species) |
pointwise_emissions_g |
Emissions in grams at each point in trajectory | (Ntot, species) |
LTO_emission_indices, LTO_emissions_g
|
LTO emission indices or emission in grams | (4, species) |
APU_emission_indices, APU_emissions_g
|
APU emission indices or emission in grams | (1, species) |
GSE_emissions_g |
Ground‑support equipment | (1, species) |
summed_emission_g |
Flight total summed emissions (trajectory+LTO+APU+GSE+Lifecycle) | (species,) |
Each of the above data points have columns (n = number of points):
| Column name | Shape |
|---|---|
CO2 |
(n,) |
HC |
(n,) |
CO |
(n,) |
NOx |
(n,) |
NO |
(n,) |
NO2 |
(n,) |
HONO |
(n,) |
PMnvol |
(n,) |
PMnvol_lo |
(n,) |
PMnvol_hi |
(n,) |
PMnvolN |
(n,) |
PMnvolN_lo |
(n,) |
PMnvolN_hi |
(n,) |
PMnvolN_GMD |
(n,) |
PMvol |
(n,) |
OCic |
(n,) |
SO2 |
(n,) |
SO4 |
(n,) |
The emissions module also calculates a total fuel burn from trajectory, APU, GSE and LTO.
NOTE:
$CO_2$ ,$H_2O$ and$SO_2$ ,$SO_4$ are scalar products of fuel burn and
need not be saved in intermediate outputs since they can be computed easily.
| ID | Artifact | Format | Granularity |
|---|---|---|---|
| O1 | Emissions by flight/aircraft type |
NetCDF‑4 (by_flight_emissions_YYYYMM.nc) |
1 row per flight |
| O2 | Total summed emissions |
NetCDF‑4 (summed_emissions_YYYYMM.nc) |
(species, total_kg) |
| Gridded emissions |
NetCDF‑4 (gridded_emissions_YYYYMM.nc) |
lon × lat × alt × time x species | |
| Model‑specific exports | Files as required by GEOS‑Chem, ACAI, other AQ/climate models |
varies |
| Term | Meaning |
|---|---|
| LTO | Landing & Take‑Off cycle (≤ 3000 ft) |
| APU | Auxiliary Power Unit |
| GSE | Ground Support Equipment |
| EI | Emission Index, g pollutant per kg fuel |