Field guide
A controlled workflow for changing point identifiers
The mapping is part of the deliverable: it explains exactly what changed and what stayed.
Allocate identifiers without moving a single observation
Use this page to renumber survey points when crews need distinct number ranges, a client requests a new numbering convention, or an exported point list must fit a documented handoff rule. It works on CSV or TXT records and changes only the mapped point-ID field. Coordinates, elevation, descriptions, additional columns and original record order remain attached to the same source observation. XLSX workbooks are also accepted for this input: explicitly choose the worksheet, and replace formulas, dates or error cells with plain values before importing.
This is not a coordinate-offset calculator. Adding one thousand to a point number does not add one thousand to northing or easting. It also does not rename references inside a survey database, update CAD labels, edit station setups or revise external field notes. Those dependencies need their own controlled update using the exported old-to-new mapping.
Start from an interpreted and checked file
Read a UTF-8 CSV or TXT file, preview its fields and identify the point-ID column. Confirm the remaining coordinate columns and source units even though this operation does not convert them. The file can use PNEZD, PENZD or another explicitly mapped layout. Original headings and extra fields are retained when the output is serialized as comma-delimited text.
Source errors block processing rather than causing rows to disappear. Fix malformed records or invalid coordinates in the checker, then import the corrected file. Missing optional elevations stay empty when permitted by the import interpretation. A file without a mapped point-ID column cannot be renumbered here; first prepare an explicit identifier column through an appropriate file-conversion workflow.
Choose sequence numbering when gaps do not carry meaning
Sequence mode assigns a new identifier to each eligible record in original source order. Set a starting value, positive integer step and optional prefix. A start of 001 with prefix A- and step two produces A-001, A-003 and A-005 for the first three eligible records. The original number need not be numeric in this mode, because it is being replaced with a complete new identifier.
The minimum width field can add more leading zeros, but it never truncates a larger number. The starting value's existing width is also retained. Protected records do not consume an item in the sequence. This makes the output predictable, but it means that the new numbers reflect the eligible source sequence rather than the original numerical spacing.
Choose an offset when the original spacing matters
Offset mode adds one fixed signed integer to each eligible digit-only original ID. For example, 0001 and 0003 with an offset of two become 0003 and 0005. Their gap is preserved, and the original minimum width remains. This can allocate a separate range to a crew while retaining a recognizable relationship to its original numbering.
The computation uses integer arithmetic rather than rounding point IDs through floating-point values. Inputs can contain up to thirty digits. A negative result, an oversized result or a target inside a reserved range blocks application. Offset mode ignores the sequence prefix and step; it is a numerical change to an existing identifier, not a way to attach letters or restart a continuous series.
Make the processing scope explicit
Leave the source-line scope empty to consider every record, or enter physical start-line ranges such as 2-50, 70, 90-120. A header contributes to physical line numbering. A correctly quoted multiline description is still one record, selected by its start line rather than every line occupied by that record. The mapping shows the original start and end lines for verification.
Filtering the preview does not change the processing scope. A hidden or later-page record can still be part of the operation, and final conflict checks cover the entire file. Use the scope field to define the actual transformation, then use the table filters only to inspect it. This prevents a view change from silently becoming an edit-selection rule.
Preserve control points and reserved number ranges
List exact point IDs to retain unchanged, one per line. This is useful for named controls such as CP01 as well as specific numerical identifiers. The comparison is literal, so an exclusion of 001 does not automatically protect a differently written 1. For a numerical control range, use the reserved-range field instead.
Reserved ranges have two effects: original digit-only IDs in the range remain unchanged, and generated numerical targets avoid that range. Sequence mode skips reserved targets while continuing by the chosen step. Offset mode cannot skip to another number without breaking its fixed-offset meaning, so such a target blocks the proposal. With a sequence prefix, the reserved range still applies to the numerical part.
Decide what letter IDs mean in offset mode
Identifiers such as CP01, A-12, plus-signed numbers or blank values are not unsigned digit-only IDs. The default offset policy blocks application when an eligible record has one of these identifiers. You can instead explicitly choose to leave them unchanged and list them in the unprocessed report. This decision is recorded with the rules.
There is no automatic extraction of trailing digits from a name. Treating CP01 as the number one could rename a control in an unintended way. If you want complete replacement identifiers, sequence mode supports that directly. If only selected numeric records should change, define the source-line scope and protected IDs so the mapping expresses that intent clearly.
Check the complete final mapping before applying it
Every proposed ID is calculated from the original record, and only then is the complete final set checked for conflicts. This allows simultaneous changes such as one becoming two and two becoming three when neither result collides with an unchanged record. An in-place loop that overwrote identifiers while still reading them would not provide the same guarantee.
Conflict checks include protected points, records outside the processing scope and all other output records. The default treats digit-only values with the same integer value as conflicting, so 001 and 1 cannot both be accepted accidentally. Exact-text comparison is available when the destination deliberately preserves those differences. Any unresolved conflict blocks application of the whole preview.
Keep duplicate old numbers traceable
Repeated old point numbers do not identify a unique observation. The mapping therefore includes the source filename, parsed record key and original line range in addition to the old and new IDs. Two records named 1001 can be assigned separate new identifiers without losing the distinction between their original coordinates or descriptions.
If repeated IDs remain unchanged outside your chosen scope, the final conflict report still flags them. A new numbering proposal does not automatically remove source duplicates. Expand the intended scope, protect the correct observations, or review the duplicate records separately. Do not use the number of distinct IDs as a replacement for the count of original records.
Use the preview as a review document
Generate the full preview after setting the rules. The summary reports input count, output count, changed IDs, unchanged IDs and unresolved conflicts. Browse pages, search old or new identifiers, and inspect changed or unchanged records. The displayed table is paginated for readability; the complete mapping remains in the report.
Confirm and apply only after those counts and examples agree with your intention. Editing a rule or reinterpreting the source invalidates the previous output immediately. Discarding the preview retains the imported source, allowing a different rule to be tested. No partial set of successful edits is applied when another record fails a rule or creates a collision.
Deliver the new points together with their mapping
Download the confirmed point CSV for the next surveying step and the mapping CSV for review. The point file preserves literal values and normal CSV quoting; it does not add spreadsheet-protection prefixes that might alter IDs or codes. The mapping document uses separate spreadsheet formula protection because its purpose is human inspection rather than instrument import.
The unprocessed list contains every record whose identifier did not change, including protected controls, out-of-scope records and explicitly retained nonnumeric IDs. The complete JSON keeps the original source, options, proposed mapping, conflicts and applied state. Save it before closing the page. A point file by itself cannot explain which numbering rule produced it or which control identifiers were deliberately retained.
Verify counts and practical limits
For this operation, input records must equal output records. Renumbering never deletes or adds an observation. In a two-row example with identical old IDs, a sequence should still produce two rows with independent new identifiers and unchanged coordinate strings. Compare several mapped rows back to the source, including a control, a leading-zero identifier and a record with extra columns.
The importer supports up to one hundred thousand records and ten MiB. Large work runs in a cancellable worker; cancelling leaves the input available. Long prefixes can increase output size, so the final point file also has a ten-MiB limit. Data remains in the browser for this session and is not automatically saved. This page does not promise offline caching or compatibility with every proprietary field-file format.