Urgent Request for ≤1m DSM/DTM/DEM for Ground-Truthing and Grievance-Based Cadastral Correction

[nchervu]

Subject: Urgent Request for ≤1m DSM/DTM/DEM for Ground-Truthing and Grievance-Based Cadastral Correction
Message:
We are submitting a terrain-sensitive grievance claim under the A.P. Survey & Boundaries Act, 1923, through the Revenue-Sadassu-2024-25 program (Grievance ID: RSELR202412208366), concerning boundary distortions and extent mismatches in Chinapalaparru Village, Mudinepalli Mandal, Eluru District, Andhra Pradesh, India.
Our technical report integrates multi-layer historical overlays, drone imagery, and AutoCAD-redrawn FMB sketches. However, the Resurvey-2020 relied on flat-surface 2D assumptions, suppressing elevation and causing misalignments from the Original Boundary Closest to Reality (ORB 1918–2020).
To correct both horizontal and vertical distortions, we urgently require access to DSM/DTM/DEM datasets with ≤1m resolution, preferably in GeoTIFF format, covering our grievance polygon. These datasets will be used for:
• Orthorectification and elevation-aware overlay correction
• Ground-truthing of encroachment zones and feeding-channel collapses
• Validation of claim polygons and extent reconciliation
• Preparation of a globally replicable grievance capsule under RIARA–ISOP and Vision India@2047
Grievance Polygon Coordinates (WGS84 / EPSG:4326):
• Vertex A: 16.476812° N, 81.170245° E
• Vertex B: 16.476812° N, 81.171812° E
• Vertex C: 16.475312° N, 81.171812° E
• Vertex D: 16.475312° N, 81.170245° E
This polygon spans two neighboring villages—Chinapalaparru and its adjacent settlement—under joint statutory study. The extended boundary is essential to capture shared encroachment zones, feeding-channel distortions, and historical boundary overlaps. Multiple grievance claims have been submitted by our family, relatives, and neighboring stakeholders, all affected by the same terrain-linked distortions. The polygon size is deliberate and justified by the grievance scope and the need for terrain continuity across village boundaries.
If ≤1m datasets are unavailable, we request the next best elevation models (e.g., NASADEM, SRTM Enhanced, AW3D Enhanced) that support terrain fidelity and vertical correction. Our goal is to submit a reality-aligned claim, as close as possible to ground-truthing, supported by elevation-aware overlays and global geospatial standards.
We appreciate your support in enabling reality-aligned cadastral reform through elevation-anchored geospatial data.
Prepared by: Chervu CSR Family
Contact: nchervu@gmail.com | +91-9962117631
Location: Vijayawada, Andhra Pradesh, India
Date: October 4, 2025

[LP DAAC - dgolon]

Hello @nchervu Apologies for the delay in response. We do not have 1 meter DEM data over your study area. NASADEM, ASTER GDEM (ASTGTM), and SRTM Version 3 data are available at a 30-meter spatial resolution. All three are available at no cost from https://search.earthdata.nasa.gov/.

More information on these datasets:
NASADEM: https://doi.org/10.5067/MEASURES/NASADEM/NASADEM_HGT.001
SRTM Version 3: https://doi.org/10.5067/MEASURES/SRTM/SRTMGL1.003
ASTER GDEM: https://doi.org/10.5067/ASTER/ASTGTM.003