Corner-Plot User Guide

Uploading a Corner Record

Supported Formats

Corner-Plot accepts PDF files for all major Corner Record formats (Corner Perpetuation & Filing forms, CP&F) — Idaho ISP Form, California LR-112, and the generic multi-state format. Multi-page PDFs are supported; each page is treated as a separate potential corner record if more than one corner appears in the document.

Via a Project

Go to Projects → New Project, give it a name, then drag PDFs directly into the project detail page. Corner-Plot queues each file for OCR and extraction. Results appear in the document list below the drop zone, and any detected corners are added to the project's corner list automatically.

Via Direct Upload

Use Upload Record in the left sidebar for a single-form, single-corner workflow. Fill in the state and form type, drag in the PDF, and click Upload. The corner record is created and the enrichment pipeline starts immediately.

Manual Entry

If you have a corner with no scanned form, you can create a stub corner record manually. Enter the PLSS description, monument type, and any known coordinates. The geolocation and Street View pipeline still run automatically.

Automatic Geolocation

The Corner Is Geolocated Automatically

The moment a Corner Record is uploaded, Corner-Plot automatically geo-locates the corner — resolving the scanned record to its correct position on the earth's surface. No manual coordinate entry, no separate GIS lookup. You can re-run it any time from the Overview tab → Geolocation card → Reconcile button.

Reading the Result

The Geolocation card shows the resolved coordinate and its confidence level (High / Medium / Low), so you always know how solid the location is at a glance.

Adopting a Custom Coordinate

If you have a field-measured coordinate that you trust more than any automated method, use Adopt Coordinate in the Overview tab. Enter the lat/lng, select the source (GPS, total station, etc.), and the coordinate is saved as authoritative. The enrichment pipeline re-runs at the new coordinate.

Coordinate System — NAD83 Today, NATRF2022 When Available

Corner-Plot currently outputs State Plane coordinates in NAD83 (NSRS2007) using US survey feet — the standard in effect for all PLSS states. The field prep report includes a reserved SPCS2022 row that will populate automatically when NGS releases the NATRF2022 horizontal datum and transformation. SPCS2022 uses international feet (exactly 0.3048 m) rather than US survey feet (1200/3937 m); the report will carry both columns side by side at that time. No user action is required.

Street View of the Monument

Street View Comes Up Automatically

As soon as the corner is geo-located — if it sits at or near a roadway — Corner-Plot brings up Google Street View of the monument automatically, along with its capture history. This runs in the background on every upload; you can also re-run it from the Street View tab → Run Classification button.

Reading the Results

The Street View tab shows one card per capture date analyzed, newest first. Each card shows the date, presence verdict, surface description, field notes, and an 'Open in Street View' link pre-aimed at the monument location. The verdict badge colors are: green = confirmed, amber = probable, red = undetected, gray = unclear.

Detected Map Marker

When a monument position is detected across one or more dates, a marker appears on the Aerial Photo map at the estimated location. Click it to see detection details.

Limitations

Detection requires Google Street View coverage within 100 feet (30 m) of the resolved coordinate. Rural corners on undriven roads, forest interiors, and private property interiors will not have coverage. Monuments obscured by snow, standing water, or heavy debris will not be detected. Urban corners on paved roads with regular Google car coverage have the best detection rates.

Ties & Cross-Checks

Ties Plotted Live at the Corner Position

Every bearing-and-distance tie extracted from the Corner Record is projected from the geo-located corner and drawn live on the map — each accessory plotted at its exact position relative to the monument, over satellite imagery with the BLM PLSS section linework. You see the whole tie geometry radiating from the corner at a glance, on-screen, without redrawing anything by hand.

On-Screen Tie Data

Each tie card shows its object class, bearing, distance (in feet), projected location, cross-check status, and a review note — right alongside the plotted point on the map, so the numbers and the position always line up.

Verify Each Tie in Street View

Every tie card includes a directional Street View link pre-aimed from the corner toward the accessory object — and a reverse link looking back from the object toward the monument. One click drops you into Street View at the tie so you can confirm the pole, tree, fence, or curb is really there before the crew drives out.

Automatic Tie Review

Each tie is automatically reviewed to note whether the referenced object appears at the projected location. A match updates the tie status; absence is treated as inconclusive rather than 'gone'. Discrepancies in object class, presence, or position are flagged for field review.

Live Corner Map

All Your Corners on One Map

The Corner Map in the left sidebar plots every geolocated corner in your account on a full-screen satellite map, color-coded by geolocation confidence, with the PLSS section grid overlaid. It's the fastest way to see where your records fall relative to one another and to the section linework.

Open a Record from the Map

Click any marker to see the corner's name, monument class, and confidence, then jump straight into its detail view — coordinate, ties, and Street View — without leaving the map.

Aerial Photo

Reading the Aerial Map

The Aerial Photo tab shows a satellite map centered on the published position. The orange pin marks the corner location. Blue dots mark tie search points. Color-coded tie dots show cross-check status: sky blue = not checked, green = present, red = gone, amber = uncertain.

Street View Links

The 'View monument ↓ in Street View' link opens Google Street View at the resolved coordinate aimed downward toward the ground surface. The ESRI Wayback link opens the ESRI historical imagery viewer for the same location.

BLM WinCMM & WinGMM

GCDB Point IDs

Every corner Corner-Plot processes is assigned a GCDB-standard 21-character Point ID — the same identifier type BLM WinCMM and WinGMM use to key a monument in the Geometric Control Data Base. The Point ID encodes the Principal Meridian, Township, Range, Section, and corner position. It appears on the corner's Overview tab and on the field prep report.

Using the Resolved Coordinate in WinCMM / WinGMM

The field prep report includes the geodetic coordinate (lat/lng) and SPCS NAD83 northing/easting in feet alongside the GCDB Point ID. These are formatted for use as control point inputs — the equivalent of a .CON file entry — in a subsequent BLM WinCMM or WinGMM least-squares adjustment session. The confidence class (High / Medium / Low) maps to the WinCMM/WinGMM NC / CR / PJ coordinate-class flags.

Tie Data and BLM WinCMM SSHOT / INREC

OCR extraction produces a bearing-and-distance tie table from the uploaded CP&F form. The structured records — bearing in decimal degrees, distance in feet, object class — correspond to the tie-sheet field data that BLM WinCMM's SSHOT and INREC routines accept. This table is the office equivalent of a WinCMM .RAW file, and it prints on the field prep report for direct transcription.

Position Resolution and BLM WinCMM TRS2LL / WHATIS / BLUNDER

Corner-Plot's automatic geolocation seeds the position from the PLSS description (TRS2LL), assigns the GCDB Point ID (WHATIS), and cross-checks the result from multiple independent methods — PLSS grid geometry, BLM cadastral nodes, road intersection geocoding, and Street View geometry. Inter-method residuals are computed and disagreement is flagged (BLUNDER), producing the confidence rating shown on every corner.

GLO Field Notes

What Are GLO Field Notes?

General Land Office field notes are the original survey records from the BLM's public land surveys, dating from the early 1800s through the mid-1900s. They describe the physical evidence found at each corner — witness trees, mounds of stone, wooden posts, and the surveyor's measurements — at the time the original government survey was run.

Accessing Them in Corner-Plot

The GLO Field Notes tab links directly to the BLM GLO Records portal for the township containing the corner. Corners with a matching township record will show a direct link to the plat and, where available, the original field note document.

Coverage

Approximately 72% of townships have a linked plat. Field note coverage is lower nationally — around 40–50% — but Idaho and Boise Meridian states have notably better field note coverage. If a township is not found, the tab shows 'Not found' without fabricating a link.