corrections of format and content

docs/documentation/analysis/ecological_assessment/basic-concepts.md

 # Basic concepts {#basic-concepts}
-This chapter provides some insight in the implemented calculation routines. The module is split into several submodules which are responsible to calculate parts of the ecological assessment. The following graph shows a rough overview of the module structure, with the end points standing for a submodule:
+This chapter provides some insight in the implemented calculation routines. The module is split into several submodules which are responsible to calculate parts of the ecological assessment. The following graph shows a rough overview of the module structure, with every end point standing for a submodule:
 <pre class='mermaid'>
   graph TD;
     A[ecological_assessment/src]-->C[standard_strategy]
@@ -18,9 +18,9 @@ The next sections will describe the submodules in detail, with information about
 The submodule _mission_emissions_ is the only part of _ecological\_assessment_ which can not be deactivated by the user, as its results are needed by all other submodules. It provides various options to calculate the emissions of kerosene or hydrogen-burning engines during a mission. Both the design and the study mission will be calculated (in the following, file names including *mission* will always mean *study_mission* and *design_mission*).
 
 ### General principles {#mission-emissions-generalprinciples}
-Depending on the defined engine carrier, the emissions will be calculated for every mission step defined in the `mission.csv` file. Only pure kerosene or pure liquid hydrogen combustion is possible, other energy carriers or hybrid variants are not implemented and will lead to a program abortion!
+Depending on the defined engine carrier, the emissions will be calculated for every mission step defined in the `mission.csv` file. Currently, only pure kerosene or pure liquid hydrogen combustion is supported, other energy carriers or hybrid variants are not implemented and will lead to a program abortion!
 
-The needed engine thermodynamics during the landing and takeoff phase (LTO) according to ICAO definition are calculated by the engine library. If you're interested in seeing a comparison between the standard ICAO LTO cycle and your aircraft design, you need to switch on the `info` mode for console or log file output inside your configuration file to get those information. Following thrust settings in percent of take-off thrust are used for LTO:
+The needed engine thermodynamics during the landing and takeoff phase (LTO) according to ICAO definition are calculated by the engine library. If you're interested to see a comparison between the standard ICAO LTO cycle and your aircraft design, you need to switch on the `info` mode for console or log file output inside your configuration file to get those information. Following thrust settings in percent of take-off thrust are used for LTO:
 
 Taxiing | Take-off | Climb | Approach |
 --------|----------|-------|----------|
@@ -37,7 +37,7 @@ The emissions of CO2, H2O, SO2, SO4 and (in a low fidelity approach) soot are co
 
 $ m_{emission} = EI * m_{fuel}$,
 
-with
+where
 
 - $ m_{emission}$: emission mass $[kg]$
 - $ EI $: emission index $[\frac{kg_{emission}}{kg_{fuel}}]$
@@ -70,7 +70,7 @@ Climb   | 6.17     |
 Cruise  | 3.14     |
 Approach| 2.4      |
 
-Alternatively, you can choose to follow the method describes in \cite Koss22 and calculate the emission index in every mission step. For that, the emissions of kerosene-burning engines are calculated via the P3T3 method and a correction factor is used to derive the emissions due to hydrogen combustion. If the calculation of a correction factor fails, the first method is used as a fallback method.
+Alternatively, you can choose to follow the method described in \cite Koss22 and calculate the emission index in every mission step. For that, the emissions of kerosene-burning engines are calculated via the P3T3 method and a correction factor is used to derive the emissions due to hydrogen combustion. If the calculation of a correction factor fails, the first method is used as a fallback method.
 
 
 
@@ -112,18 +112,18 @@ In the `ecological_assessment_conf.xml`, next to the control settings block, you
     - duration_operation
 ```
 
-From `mission.xml`, the taxi time and range will be read :
+From `mission.xml`, the taxi time and mission range will be read :
 ```xml
 - taxi_time_origin
 - taxi_time_destination
 - range
 ```
-Additionally, you need to provide the `mission.csv` file written by the UNICADO *mission_analysis* module and located in _aircraft\_exchange\_file\_directory/mission_data_.
+Additionally, you need to provide the `mission.csv` file written by the UNICADO [mission analysis](../mission_analysis/index.md) module and located in _aircraft\_exchange\_file\_directory/mission_data_.
 
-And last but not least, the engine library will be used, so you can check the documentation page of the library to get information about its input files.
+And last but not least, the engine library will be used, so you can check the documentation page of the [engine library](../../libraries/index.md) to get information about its input files.
 
 ### Output data {#mission-emissions-output}
-The central output of the mission submodule is the `ecological_assessment_results_file.xml` which you will find in the *aircraft\_exchange\_file\_directory/reporting/report_xml* directory. It contains all calculated emission masses. Additionally, there is a `...emissionspath.csv` file in the folder *aircraft_exchange_file_directory/mission_data/* including mission and engine data for every mission step.  As described in [Module usage](#usage), an HTML report including plots with emission flows will be generated.
+The central output of the mission submodule is the `ecological_assessment_results.xml` which you will find in the *aircraft\_exchange\_file\_directory/reporting/report_xml* directory. It contains all calculated emission masses. Additionally, there is a `...emissionspath.csv` file in the folder *aircraft_exchange_file_directory/mission_data/* including mission and engine data for every mission step.  As described in [Module usage](#usage), an HTML report including plots with emission flows will be generated.
 
 
 ## LCA Schaefer {#lca-schaefer}
@@ -131,7 +131,7 @@ The method is based on the dissertation by Katharina Schäfer (2011) \cite Sch17
 
 ![](figures/lifeCyclePhases.png "Life cycle phases according to K.Schaefer")
 
-The method is only applicable for conventional tube and wing aircraft, powered by kerosene. This will be checked and the program skips the life cycle emission calculation in case you try to assess fancy unconventional aircraft designs :wink:.
+The method is only applicable for conventional tube and wing aircraft, powered by kerosene. This will be checked and the program skips the life cycle emission calculation in case you try to assess fancy unconventional aircraft designs :wink:
 
 ### General principles {#lca-schaefer-generalprinciples}
 For all processes within the four phases, an inventory analysis is conducted. In a first step, all relevant inputs are collected, such as materials, fuel and energy demand. Next, the resulting emissions are determined. For background processes, data provided primarily by [GaBi Software](https://ghgprotocol.org/gabi-databases) is used, offering emission data for material extraction, fuel production, energy production, and more. With this data, emissions resulting of the determined resources are calculated as follows:
@@ -142,7 +142,7 @@ $ Em_{fuel} = Em_{fuel}^* \cdot f + Em_{com}$
 
 $ Em_{mat} = Em_{mat}^* \cdot m_{mat} $
 
-with
+where
 
 - $ Em_{energy} $: Emissions due to energy production (both electric and heat energy) [kg]
 - $ Em_{fuel} $: Emissions due to fuel production and combustion [kg]
@@ -155,7 +155,7 @@ with
 - $ f $: Fuel demand [kg]
 - $ m_{mat} $: Material demand [kg]
 
-The emissions of CO2, H2O, NOx, CO, SO2, CH4, HC and soot are determined. For the testing phase during development, perfluorinated hydrocarbons (PFC), non methane volatile organic compounds (NMVOC) and nitrous oxide emissions (N2O) are additionally calculated.
+The emissions of CO2, H2O, NOx, CO, SO2, CH4, HC and soot are determined. For the testing phase during development, perfluorinated hydrocarbons (PFC), non methane volatile organic compounds (NMVOC) and nitrous oxide emissions (N2O) are calculated in addition.
 
 If recycling is enabled, emissions in the end-of-life phase can be negative, as the emissions saved in the production phase due to recycling are accounted for here.
 
@@ -166,25 +166,25 @@ Both electric and heat energy demand for engineering is determined by:
 
 $  E = E^*  \cdot A \cdot \frac{t}{h} $
 
-with
+where
 
 - $E$: (Electric and heat) energy $[MJ]$
-- $E^*$: Specific energy per area $[MJ/(m^2 \cdot a)]$
+- $E^*$: Specific energy per area $[\frac{MJ}{m^2 \cdot a}]$
 - $A$: Gross floor area $[m^2]$
 - $t$: Engineering hours $[h]$
 - $h$: Hours per year $[h/a]$
 
 Testing is split into wind tunnel test, structure tests, system tests, ground tests, engine tests and flight tests.
 
-The wind tunnel tests (index: wt) only use energy E [JM], depending on the time spend in the wind tunnel t [s] and power demand P [MW]:
+The wind tunnel tests (index: wt) only use energy $E$ [MJ], depending on the time spend in the wind tunnel $t$ [s] and power demand $P$ [MW]:
 
 $ E_{wt} = t_{wt} \cdot P_{wt}$.
 
-For structure tests (index: struc), production and end of life (eol) of the test components are considered. As the emissions resulting from energy, material and fuel demand of those components are calculated within the according phases, the resources are not determined here - instead, the emissions are directly summed up from existing data. Additionally, there is some energy needed for carrying out the tests. The energy E [MJ] is calculated using a linear correlation for the needed hydraulic and pneumatic power, depending on the number of load cycles n [-] and the maximum take off mass MTOM [t]:
+For structure tests (index: struc), production and end of life of the test components are considered. As the emissions resulting from energy, material and fuel demand of those components are calculated within the according phases, the resources are not determined here - instead, the emissions are directly summed up from existing data. Additionally, there is some energy needed for carrying out the tests. The energy $E$ [MJ] is calculated using a linear correlation for the needed hydraulic and pneumatic power, depending on the number of load cycles $n$ [-] and the maximum take off mass $MTOM$ [kg]:
 
-$E_{struc} = n \cdot MTOM * 1.45 \frac{J}{kg}$
+$E_{struc} = n \cdot MTOM \cdot 1.45 \frac{MJ}{kg}$
 
-The system tests (index: sys) are divided into integration tests and iron bird tets. The needed energy E [MJ] is estimated using the maximum design power of the electric, pneumatic and hydraulic aircraft systems P [MW] and the testing time t [s]:
+The system tests (index: sys) are divided into integration tests and iron bird tets. The needed energy $E$ [MJ] is estimated using the maximum design power of the electric, pneumatic and hydraulic aircraft systems $P$ [MW] and the testing time $t$ [s]:
 
 $E_{sys} = P \cdot t_{sys}$
 
@@ -194,7 +194,7 @@ $E_{gt} = P \cdot t_{gt}$
 
 Additionally, emissions for taxi tests are considered. As they are calculated in the mission submodule anyway, the are summed up directly instead of calculating the resources here. It is assumed, that the total ground test time equals the flight test time, and the taxi test time is 5% of the total ground test time.
 
-Engine tests are divided into rig tests (index: rig) and test on an flying test bed (index: ftb). For the fuel demand f [kg], the number of test engines n [-], their thrust specific fuel consumption TSFC [(kg/s)/kN] and thrust T [kN] both for cruise condition c, and maximum max as well as share of those values x [-] and total time t [s] are needed:
+Engine tests are divided into rig tests (index: rig) and test on an flying test bed (index: ftb). For the fuel demand $f$ [kg], the number of test engines $n$ [-], their thrust specific fuel consumption $TSFC$ [(kg/s)/kN] and thrust $T$ [kN] both for cruise condition $c$, and maximum $max$ as well as share of those values $x$ [-] and total time $t$ [s] are needed:
 
 $ f_{rig} = n \cdot t_{rig} (\cdot (TSFC_{max} \cdot T_{max} \cdot x  +  TSFC_{c} \cdot T_{c} \cdot (1 - x))) $
 
@@ -220,13 +220,15 @@ The energy of labour is determined based on the actual working hours, the yearly
 
 $ labourCosts = 0.41 \cdot (recurringCosts - finalAssemblyCosts) $
 
+<div class="mathjax-render">
 $ energy [MJ] = specificEnergy [MJ/a] \cdot \frac{labourCosts [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} $
+</div>
 
-For the material demand m [kg] of one aircraft component (index: ac), the component weight W [kg], the material ration mr [-] and the scrap ratio sr [-] are needed:
+For the material demand $m$ [kg] of one aircraft component (index: ac), the component weight $m_{comp}$ [kg], the material ration $mr$ [-] and the scrap ratio $sr$ [-] are needed:
 
-$ m_{ac} = \frac{mr \cdot W}{1-sr} $
+$ m_{ac} = \frac{mr \cdot m_{comp}}{1-sr} $
 
-This is done for all components and all considered materials (aluminum, CFRP, steel, titanium, nickel) and summed up for a total value. Whereas the competent masses are read from the aircraft exchange file, all other values can be found hardcoded in the module database. Also part of the database are the values for recycling of primary scrap. The raw material demand (index: raw) per material (index: mat)and component is:
+This is done for all components and all considered materials (aluminum, CFRP, steel, titanium, nickel) and summed up for a total value. Whereas the component masses are read from the aircraft exchange file, all other values can be found in the module database. Also part of the database are the values for recycling of primary scrap. The raw material demand (index: raw) per material (index: mat) per component is:
 
 $ m_{mat, raw} = m_{ac} \cdot (1- sr \cdot recoveryRate) $
 
@@ -234,45 +236,55 @@ Therefor, the whole raw material demand for a component is:
 
 $ m_{ac,raw} = \sum m_{mat, raw} $
 
-The energy demand for material processing does not consider the scrap ratio, as the values for specific energy demand are valid per aircraft component. The energy is calculated per material and summed up:
+The energy demand for material processing does not consider the scrap ratio, as the values for specific energy demand $E^{*}_{mat}$ are valid per aircraft component. The energy demand is calculated per material and summed up:
 
-$ E_{component} = \sum specificEnergyMaterial \cdot mr \cdot W $
+<div class="mathjax-render">
+$ E_{comp} = \sum E^{*}_{mat} \cdot mr \cdot m_{comp} $
+</div>
 
-The fuel demand for transportation is based on a Airbus transportation network scenario which is hardcoded in the module. For every transportation/fuel type, the amount of fuel is calculated based on the components weight and transport distance:
+The fuel demand for transportation is based on a Airbus transportation network scenario which is defined in source code of the module. For every transportation/fuel type, the amount of fuel $f$ [kg] is calculated based on the components weight $m_{comp}$ [t], the transport distance $d$ [km] and a fuel specific fuel consumption $f^*$ [kg/(km$\cdot$t)]:
 
-$fuel [kg] = mass [t] \cdot distance [km] * fuelConsumption [kg/(km\cdot t)]$
+$f = m_{comp} \cdot d \cdot f^* $
 
 For the final assembly, mainly personnel work and therefor electrical and heat energy is required. Again, the working hours are derived from costs:
 
+<div class="mathjax-render">
 $energy [MJ] = specificEnergy[MJ/a] \cdot \frac{finalAssemblyCosts [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} $
+</div>
 
-The fuel for final flight tests are determined as the first flight tests:
+The fuel for final flight tests (index: ft) are determined as the first flight tests:
 
 $f_{ft} = f_{mission} \cdot \frac{t_{ft}}{t_{mission}}$
 
 #### Operation resources
-During the operation phase, flight are performed and maintenance is necessary. The needed fuel for operation can be read from the mission calculation and is not calculates in this phase. Resources for maintenance are production resources for spare parts and labour energy (heat and electricity). For the spare parts, resourced determined in the production phase are used. It is assumed, that the ratio of the maintenance material costs of a certain component and the corresponding recurring costs of that component is equal to the ratio of resources of the spare parts and of manufacturing of the specific component. For labour energy, direct maintenance costs are used and the amount of operating years t considered:
+During the operation phase, flights are performed and maintenance is necessary. The needed fuel for operation can be read from the mission calculation and is not calculates in this phase. Resources for maintenance are production resources for spare parts and labour energy (heat and electricity). For the spare parts, resources determined in the production phase are used. It is assumed, that the ratio of the maintenance material costs of a certain component and the corresponding recurring costs of that component is equal to the ratio of resources of the spare parts and of manufacturing of the specific component. For labour energy, direct maintenance costs are used and the amount of operating years t considered:
 
-$energy [MJ] = specificEnergy[MJ/a] \cdot \frac{directMaintenanceCosts [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} \cdot t [yr]$
+$energy [MJ] = specificEnergy[MJ/a] \cdot \frac{directMaintenanceCosts [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} \cdot t [a]$
 
 
 #### End of life resources
 In the end of life (EoL) phase, the transport to EoL-site, disassembly, dismantling and recycling/incineration/landfill are considered.
-The transport to EoL-site is handled like a flight with a certain distance and the fuel demand f determined via the range R [NM] of this flight compared to the range of the known mission:
+The transport to EoL-site is handled like a flight with a certain distance and the fuel demand $f$ [kg] is determined via the range $R$ [NM] of this flight compared to the range of the known mission:
 
 $f_{EoL} = f_{mission} \cdot \frac{R_{EoL}}{R_{mission}}$
 
-Resources for disassembly and dismantling are determined as for the final assembly, but no heat energy is required as the the process takes place outdoors.
+Resources for disassembly and dismantling are determined as for the final assembly, but no heat energy is required as the the process typically takes place outdoors.
 
-$energy [MJ] = specificEnergy[MJ/a] \cdot \frac{costs [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} \cdot t [yr]$
+$energy [MJ] = specificEnergy[MJ/a] \cdot \frac{costs [\$]}{wage [\$/h] \cdot hoursPerYear [h/a]} \cdot t [a]$
 
-The EoL scenario hardcoded in the module contains recycling, incineration and landfill rates for the aircraft components. The energy needed for all materials/components and all cases is summed up. With the ratios of incineration and landfill, the energy for all components and materials are calculated like this:
+The EoL scenario defined in the module contains recycling, incineration and landfill rates for the aircraft components. The energy needed for all materials/components and all cases is summed up. With the ratios of incineration and landfill, the energy for all components and materials are calculated like this:
 
-$ energy [MJ] = specificEnergy [MJ/kg] \cdot componentMass \cdot  $
+$ E = E^*\cdot m_{comp} $
 
-For recycling, the energy rate ER is needed additionally:
+where
 
-$ energy [MJ] = \frac{1}{ER} \cdot specificEnergy [MJ/kg] \cdot componentMass \cdot  $
+- $E$: Energy $[MJ]$
+- $E^*$: Specific energy $[MJ/kg]$
+- $m_{comp}$: Mass of component $[kg]$
+
+For recycling, the energy rate $ER$ [-] is needed additionally:
+
+$ E = \frac{1}{ER} \cdot E^*\cdot m_{comp} $
 
 ### Input data {#lca-schaefer-input}
 The calculation results depend on following user inputs the aircraft exchange file:
@@ -497,7 +509,7 @@ $ AQI = 1/n \cdot \sum x_i/x_{i,max}$
 where:
 
 - $ x_i $: emission mass [g] ( for CO, HC, NOx) or maximum concentration [mg/m^3] ( for soot) during the landing and takeoff cycle,
-- $ x_{i,max}$: regulatory value defined by ICAO, the ratio of emission mass Dp [g] emitted during LTO and the rated thrust F00 [kN],
+- $ x_{i,max}$: regulatory value defined by ICAO (the ratio of emission mass $Dp$ [g] emitted during LTO and the rated thrust $F00$ [kN]),
 - $ n $: number of emission species.
 
 ### Input data {#aqi-schaefer-input}
@@ -518,10 +530,10 @@ From `ecological_assessment_results.xml` the emissions during LTO of the study m
     - study_mission
         - emissions
             - LTO_cycle
-            - HC
-            - CO
-            - NOx
-            - c_soot_LTO_max
+              - HC
+              - CO
+              - NOx
+              - c_soot_LTO_max
 ```
 ### Output data {#aqi-schaefer-output}
 The submodule writes its calculation results into the HTML report located in *aircraft_exchange_file_directory/reporting/report_html*.
@@ -532,7 +544,7 @@ The climate model calculates key climate impact metrics: Radiative Forcing (RF),
 The key metrics are:
 
 - **RF**: quantifies the change in energy flux in the Earth's atmosphere due to emissions, specifically related to greenhouse gases, aerosols, and other components like soot or water vapor.
-- **AGWP**: measures the cumulative impact of an emission over a specific time horizon (typically 20, 100, or 500 years), comparing it to CO₂'s effect.
+- **AGWP**: measures the cumulative RF of an emission over a specific time horizon (typically 20, 100, or 500 years).
 - **AGTP**: calculates the temperature change due to emissions at a given point in time, typically looking at how gases contribute to warming.
 - **ATR**: ATR evaluates the mean temperature change over time.
 
@@ -547,12 +559,23 @@ Additionally aircraft induced cloudiness (AIC) is considered.
 
 A particular feature of the method is the usage of forcing factors, which are unitless parameters. These factors modify the radiative forcing for emissions at different altitudes by normalizing the RF values to a fleet wide average. The altitude is the only flight trajectory parameter considered, meaning the geographic location is not factored into the calculations. This altitude dependency recognizes that emissions at higher altitudes (such as those from aviation) have a different forcing impact compared to emissions at ground level, as atmospheric processes and the distribution of pollutants vary with height.
 
-In the model, you can explore how the influence of time affects climate impact by adjusting the rate of devaluation for temperature response. A value of zero indicates that the temperature changes occurring after operations are given equal weight compared to changes during the operational period. Higher values of the rate, however, signify that postoperation impacts become progressively less important over time, with each subsequent year's temperature change being less significant than that of the previous year.
+In the model, you can explore how the influence of time effects climate impact by adjusting the rate of devaluation for temperature response. A value of zero indicates that the temperature changes occurring after operations are given equal weight compared to changes during the operational period. Higher values of the rate, however, signify that postoperation impacts become progressively less important over time, with each subsequent year's temperature change being less significant than that of the previous year.
 
 ### General principles {#climate-model-generalprinciples}
-The submodules is based on the emissions calculated by the mission submodule. The values are read and scaled to one year, to get the yearly emission mass E.
+The submodules is based on the emissions calculated by the mission submodule. Following metrics are calculated, always for one kilogram of one emission species, for the annual amount of this emission and finally for all emission species together:
+
+<pre class='mermaid'>
+  graph LR;
+  A[Emissions]-->B[RF]
+  B-->C[Normalized RF]
+  C-->D[Temperature Change]
+  D-->E[Weighted Temperature Change]
+  E-->F[ATR]
+</pre>
+
+In a first step, the emission masses are read and scaled to annual emissions.
 
-To calculate the radiative forcing following formulas are used:
+Afterwards, following formulas are used to calculate the radiative forcing:
 
 $ RF(t, h) = s_i(h) \cdot \int_{0}^{t} G_i(t-\tau)E_i(\tau)d\tau$  for  $i \in [CO_2, O_{3L}, CH_4]$
 
@@ -560,7 +583,7 @@ $ RF(t, h) = s_i(h) \cdot \left(\frac{RF_{ref}}{E_{ref}}\right)\cdot E_i(t)$  fo
 
 $ RF_{AIC}(t, h) = s_{AIC}(h) \cdot \left(\frac{RF_{ref}}{L_{ref}}\right)_{AIC}\cdot L(t)$
 
-with
+where
 
 - $RF$: radiative forcing [W/m^2]
 - $s_i$: forcing factor [-]
@@ -606,7 +629,7 @@ with the weighting function:
   $
 </div>
 
-with
+where
 
 - $t$: current year
 - $t_{max}$: considered time frame