GSI Format Guide

Status: Research brief below. Replace this entire body with finished MDX when research is complete. Update description in frontmatter.

Target route: /reference/data-formats/gsi

Paired tools: /tools/converters/gsi-to-csv, /tools/converters/csv-to-gsi

AI research prompt

You are writing a Reference guide (not a beginner lesson) for Surveying Core. Produce a single MDX-ready document (article body only). Published at /reference/data-formats/gsi as the authoritative Leica GSI Format Guide for the platform.

Pair bidirectionally with:

• GSI → CSV — /tools/converters/gsi-to-csv
• CSV → GSI — /tools/converters/csv-to-gsi

Cross-link File Conversion Overview: /learn/tools/file-conversion-overview

Audience

• Surveyors and technicians who must read, debug, or produce GSI files
• Software developers porting parsers (secondary audience — keep developer notes in a dedicated subsection)
• Office staff troubleshooting failed imports

Research sources you must consult

Prioritise primary manufacturer / format documentation:

• Leica Geosystems GSI / SDU format descriptions (GSI-8 and GSI-16)
• Total Open Station / System 1200 documentation where GSI exchange is defined
• Surveying Core internal notes (for alignment only): Ground of truth/PLUGIN_FORMAT_AND_CONVERTER_ENGINE_ANALYSIS.md §2.4

Do not invent field codes. If a code is uncertain, say so and cite what you found.

Platform implementation facts (article must align)

Surveying Core’s browser parser behaviour (describe these accurately for users):

GSI-16 detection: presence of *11 style records indicates GSI-16 variant.

GSI-16 word pattern: tokens matching *?FFLLLL+value (field FF, line LLLL).

GSI-16 coordinates: point id and E/N/Z encoded in fixed-width numeric words with scaling (coordinates effectively stored with decimal precision via integer encoding — explain at user level and developer level).

GSI-8 structure: line-oriented; prefix codes such as:

• 11.. + point id
• 81.. easting (divide stored value by 1000 for metres)
• 82.. northing (÷ 1000)
• 83.. elevation (÷ 1000)
• 41.. description/code

Business rules users should know:

• Points at E=0 and N=0 with point number "0" may be skipped on import (mention implication)
• Variant must be detected before export (CSV→GSI tool exports GSI-8 by default in MVP UI — note if docs specify otherwise)

Scope — must cover

1. What GSI is and which instruments/software produce it (Leica ecosystem focus)
2. GSI-8 vs GSI-16: when each is used; how to tell them apart in a file
3. Record / word structure for each variant (tables of prefix / field codes)
4. Coordinate encoding and units (metres; scaling factors)
5. Point identity and description fields
6. Minimal valid file examples: show short synthetic snippets (3 points) for GSI-8 and GSI-16 in fenced code blocks — use realistic formatting, not lorem ipsum
7. Common malformed files and diagnostic symptoms (wrong scale, missing line terminators, mixed variants)
8. Round-trip expectations GSI → CSV → GSI (what metadata is lost)
9. Relationship to USDM (canonical easting/northing/elevation/id/code in app)
10. Links to converters and conversion overview article

Out of scope

• Full Leica proprietary job formats unrelated to GSI point exchange
• SDR, IDX, or other manufacturer formats
• Binary encodings not used in MVP text GSI
• DWG/DXF (separate converters)

Quality bar

• Reference tone: precise, lookup-friendly, tables and code samples
• No tutorial filler
• Include field code tables for GSI-8 and GSI-16
• Include two minimal sample files (GSI-8 and GSI-16) with annotated line-by-line explanation
• Troubleshooting section mapped to converter error messages users might see
• References section with URLs or document titles
• WCAG-friendly structure: start at ##; use tables with header rows; code blocks for samples

Deliverable format

Return MDX body only. Suggested outline:

1. Overview
2. GSI-8 vs GSI-16
3. GSI-8 format specification
4. GSI-16 format specification
5. Coordinate scaling and units
6. Sample GSI-8 file (annotated)
7. Sample GSI-16 file (annotated)
8. Import/export behaviour on Surveying Core
9. Round-trip and data loss
10. Troubleshooting
11. Developer notes (parser hooks)
12. References
13. Related tools (converter links)

Target length: 2,500–3,500 words (reference may be longer than Learn articles).