8.3.7.4.1 Occupational Data.
The U.S. Census Bureau also provides a breakdown of the working (civilian) population by industry and occupation. These include industry categories such as manufacturing; transportation and warehousing; retail trade; professional, scientific, management, and administrative; and arts, entertainment, recreation, accommodation, and food services. Although exact building structure types cannot be determined per industry category, building standards and other potential sources may be used to generalize building structure types per industry category. Applicants should also consider occupations that may cause the workers to be outside, or “unsheltered,” for a certain percentage of their time (e.g., construction workers, agricultural workers).
8.3.7.4.2 Building Height.
Applicants should account for the floor makeup of a building where there might be more than one floor. Location of people on different floors plays an important part when determining risk. The person at the top floor will experience different risk than a person five stories below them. Typically, only three floor types should be considered: the top floor, the floor beneath the top floor, and all other floors below. For simplicity, the applicant may want to just consider that all the other floors below the first two top floors will experience similar risk. To determine how many people are located on each floor, assumptions should be made. For example, the applicant may assume that a person in a four-story building has a 25 percent likelihood of being on any of the four floor levels.
8.3.7.4.3 Schools.
The U.S. Census also provides information of people enrolled in school from grades one through college. Depending on the type of school that people are enrolled in, the applicant may make engineering judgments to create building type distributions. Schools will usually have a building code they must adhere to. The building code can vary by region. It can also vary by school type (e.g. elementary schools, high schools, universities, and daycare facilities). Many schools also utilize temporary buildings or “portables,” which will have a different structure type compared to a permanent building. It is possible that this code has changed over time, so the applicant should identify when the school was built to correctly categorize the structure type.
8.3.7.5 Global Data.
Outside the U.S., demographic data that is useful for sheltering is scarce.
The most useful data are the fraction of people in different occupations and in school and the gross domestic product (GDP) per capita. A correlation exists between GDP per capita and the type of construction. In general, a different model for sheltering should be used in rural than urban areas. The sheltering model should also account for typical building 33
materials in the region of the world (some regions primarily use wood, whereas others use much more concrete).
8.3.8 Process for Data Maintenance.
To meet the “timely source data” requirement of § 450.123(b)(3), an applicant should ensure that the data products are the best available and up-to-date. Many population data services offer regular updates to their products. Data should be updated as appropriate to meet the analysis accuracy required for each mission. This does not mean that all the population modeling data should be updated for every mission, especially if there are multiple missions per year. Critical information to be addressed for each mission includes launch and reentry site population, including spectators if any population growth, redistribution, and changes in sheltering.
8.3.9 On-facility and Near-facility Data.
On-facility and near-facility population data should be updated at least annually, or if any significant development occurs. Spectator data should be updated for each mission based on lessons learned and confirmed that it does not exceed the expectation in the mission countdown.
8.3.10 Large Region Data.
Large Region data should use estimated growth rates to stay current, and with full updates at least every decade. If the uncertainties associated with a growth-model approach are small relative to other sources of uncertainty in the individual and EC computed to demonstrate compliance with § 450.101, then the current population P may be estimated from the formula, where the annual growth rate G is a percentage/100, and the exponent is the number of years between the starting population value and the current population estimate. For near-launch and reentry areas (where the dispersion of hazardous debris is smaller), the starting population input data should be re-evaluated approximately every two years, and for downrange areas every decade (e.g. following the U.S. Census).
𝑃𝑃𝑐𝑐𝑐𝑐𝑤𝑤 = 𝑃𝑃𝑤𝑤𝑠𝑠𝑤𝑤(1 + 𝐺𝐺)∆𝐺𝐺 Where Pnew = total current population Pold = starting population value G = annual growth rate of population ∆G = number of years between the starting population value and the current population estimate 34
8.4 Accounting for Vulnerability of People.
In accordance with § 450.123(b)(4), the exposure analysis must account for the vulnerability of people to hazardous debris effects. To accomplish this, the exposure model should characterize the type of structure, vessel, etc., in which people are located.
An applicant should use the consequence modeling found in §§ 450.135, 450.137, and
450.139 when computing risk. An applicant should refer to AC 450.137 Distance Focusing Overpressure (DFO) Risk Analysis, and AC 450.139-1 Toxic Hazard Risk Analysis.
8.5 Ensuring Documentation, Traceability, and Configuration Management.
It is critical to maintain the documentation and traceability of all data used in a population model to: (1) allow for compliance monitoring (§ 450.209); (2) preserve data in the event of a mishap (§ 450.173(d)(4)); and (3) facilitate changes or updates using additional input data (§ 450.123(b)(3)). A configuration management process should be implemented for dataset updates to ensure that analysts use the best available data. One approach used by many of the Federal sites is to organize and maintain combined population and structures data using a database software tool. This approach allows for querying of the master data set to extract population data needed for specific missions.
A launch or reentry site operator would be a logical custodian of population and structural data for the on-site population and the surrounding area out to approximately 32 km around the launch site. However, this approach is not a requirement of the launch or reentry site operator. The downrange population data is more mission specific and is typically the responsibility of the launch/reentry license applicant to develop, although commercial sources are available.
9 POPULATION EXPOSURE ANALYSIS - APPLICATION REQUIREMENTS.
To satisfy the application requirements of § 450.123(c), an applicant must submit a description of the models used to develop the exposure input data in accordance with § 450.115(c), and complete population exposure data in tabular form.
9.1 Description of Methods.
Section 450.123(c)(1) requires that an applicant submit a description of the methods used to develop the exposure input data in accordance with § 450.115(c) as described in paragraph 1.2. In addition, the applicant should explain the methods used when categorizing populations. There should be a description of what resolutions were used for what areas and why. Additionally, the applicant should describe the methods and assumptions used to temporally distribute populations. Applicants should record how they determined the sheltering and describe how they characterized structures. Data sources used should be documented to include how old the data is and what the applicant did and will do to maintain the timeliness of the data, if necessary. If surveys are done, the applicant should explain what was surveyed and what information was recorded. If surveys were not done, applicants should explain how they obtained data of the on-facility and near-facility populations.
9.2 Complete Population Exposure Data.
Section 450.123(c)(2) requires that an applicant submit its complete population exposure data, in tabular form. Common file formats should be used, such as comma separated values or spreadsheet. Documentation should explain each field, including units, and the purpose of each file provided. This data should include information on both structure classes and population data.
9.2.1 Structure Classes.
The applicant should submit a list of structure classes used in the population exposure analysis. Data for each structure class should include:
• Structure class unique identifier
• Structure class description
• Size category (area)
• Glass to floor ratio
• Wall/frame type
• Roof type
• Window type
9.2.2 Population Data.
The applicant should submit a list of all population centers used in the population exposure analysis. If there are significant variations as a function of time, these different variants should be provided as well. This may instead be accomplished by providing the 36
FAA the software/database from which population data is obtained. Population data should include:
• Population center name
• Population center area
• Geodetic latitude and longitude of population center centroid
• Structure classes associated with the population center
• Number of people in each structure class
• Number of structures in each structure class
9.3 Variable Population Data.
For population centers where the population will only be known at the time of launch, such as spectator areas, the applicant should provide the expected ranges of people present. The applicant should calculate the maximum number of people allowed at each site that still meets the safety criteria of § 450.101 prior to the day of operation, accounting for all foreseeable conditions within the flight commit criteria, per § 450.135(a)(1). Alternatively, the Flight Safety Analysis must include a debris risk analysis that demonstrates compliance with safety criteria in § 450.101 during the countdown using the best available input data, including flight commit criteria and flight abort rules, in accordance with § 450.135(a)(2). The operator should ensure that the number of people present is below the number used in its analysis.
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FAA Form 1320-73 (06-2020)