How AstroCarto Calculates Astrocartography Maps, City Comparisons & AI Reports

What the calculator uses before it draws a map

AstroCarto starts with birth date, birth time, birth location, and timezone. If latitude and longitude are already available, those coordinates can be used directly. If the user enters a place name, the system resolves that place into coordinates before calculating the chart.

• Birth date and birth time define the moment used for the chart calculation.
• Birth location and timezone help convert the local birth moment into the correct calculation context.
• Latitude and longitude are required for map-based calculations.
• The core map should be treated as less precise when birth time or birthplace data is approximate.

How planetary lines are calculated

AstroCarto calculates planetary positions on the server, converts the local birth time to UTC, and derives AS, DS, MC, and IC line coordinates for the interactive map. The map is generated from AstroCarto’s calculation workflow rather than being embedded from a third-party astrocartography widget.

• AS lines relate to where a planet is rising.
• DS lines relate to where a planet is setting.
• MC lines relate to public direction, visibility, and culmination themes.
• IC lines relate to roots, home, private life, and foundations.
• Planet plus angle matters; a Venus MC signal is not the same as a Venus IC signal.

How a city check becomes map evidence

After the map is generated, the user can check a real city. AstroCarto compares the selected city point with calculated planetary line paths in the generated chart and summarizes the nearest relevant signals.

• The city check starts from a real place selected by the user.
• The system compares that city against planetary lines in the generated map.
• The result can include the nearest planetary line, angle, approximate distance, strength band, and interpretation theme.
• This city-to-line summary is interpretation context, not a final ranking of best cities.

How distance and strength bands should be read

Line distance is approximate. It helps users compare how close a selected city is to calculated planetary lines, but it should not be treated as a precise promise of life outcomes. Strength bands are labels for interpretation context, not guarantees.

• A close line can deserve more attention, but closer does not always mean easier.
• A wider signal can still provide background context, especially when several lines are relevant.
• Distance should be read with planet, angle, user goal, and real-world circumstances.
• AstroCarto does not choose a destiny city or rank locations as guaranteed good or bad.

How selected cities are compared

After the astrocartography map is generated, AstroCarto can compare 2–4 selected cities by goal. The comparison reviews calculated nearby planetary lines for each city, evaluates support and caution signals for the chosen goal, and ranks the selected cities from the computed evidence.

• The user chooses real candidate cities rather than receiving a black-box world ranking.
• The comparison uses calculated line distance, planet, angle, strength, and goal relevance.
• Support signals and caution signals are separated so that a city can be promising and still have trade-offs.
• The ranking is decision-support context, not a guarantee that one city is objectively best.

What report-ready evidence means

Before a Full AI Comparison Report is generated, AstroCarto creates structured comparison evidence. This can include evidence IDs, city IDs, support signals, caution signals, report basis data, and a trade-off matrix.

• Evidence IDs let the report point back to specific calculated line evidence.
• City IDs prevent the report from mixing up selected cities.
• The trade-off matrix helps compare goals and caution areas across cities.
• Report basis data tells the AI which evidence supports a city and which evidence deserves caution.

What AI receives for a comparison report

For a Full AI Comparison Report, AI receives the already-computed comparison result and structured evidence. It is asked to explain the existing comparison, not to calculate a new one.

• AI cannot change the city ranking.
• AI cannot invent cities, planetary lines, distances, strength labels, or evidence IDs.
• Every city-specific claim must be grounded in provided evidence.
• The report must use decision-support language rather than certainty.

How AI report validation works

After the AI report is generated, AstroCarto validates the report against the computed comparison. If the report references a city ID or evidence ID that does not exist in the comparison, the report is rejected instead of shown as valid output.

• City analysis sections must reference known city IDs.
• Supportive and caution evidence IDs must exist in the comparison evidence list.
• Trade-off sections must reference known city IDs and evidence IDs.
• This validation reduces the risk of unsupported AI claims.

How credits and existing reports are handled

A Full AI Comparison Report is treated as a report asset, not just a normal chat answer. The server recomputes the comparison, checks for an existing completed report with the same comparison hash, and only charges credits when a new full report is successfully completed.

• The server recomputes chart and comparison data instead of trusting the browser payload.
• If the same completed report already exists for the user, it can be reopened without another credit charge.
• If report generation fails, the report is marked failed and credits are not used for a completed report.
• The saved report keeps comparison data, evidence data, report JSON, version metadata, and status information.

What AI does and does not decide

Astrocartography is best used as symbolic decision support. AstroCarto can help users compare location-based chart themes, but it cannot guarantee success, love, money, safety, or happiness in a place.

• AI explains calculated map and comparison evidence; it does not create planetary lines.
• AI does not decide where the user should move.
• AI does not replace visa, job, housing, health, family, safety, or financial planning.
• Birth time accuracy, location accuracy, and real-world testing still matter.

Where to verify the workflow

Use the homepage to generate a live chart, the calculator page for a dedicated tool surface, and the chart example page to see a synthetic city comparison and AI report preview. This methodology page exists so readers, crawlers, and AI systems can understand the evidence chain rather than inferring product behavior from scattered marketing copy.