How Drishti works

Drishti turns free, open satellite imagery into a dated, verifiable record of how a piece of land changes over time. This page explains the data, the method, the evidence report, the known limits, the licensing, and the terms of use.

1. Overview

Drishti is a satellite progress-monitoring service. Given a location and a time period, it builds an interactive timeline of that exact patch of ground — a play-through timelapse and a before/after slider — plus a downloadable evidence report. It is used to document construction and property progress, verify development claims, and record land & vegetation change such as deforestation or mangrove loss.

The imagery comes from the European Union's Copernicus Sentinel-2 programme, which is open data — free to use and publish, including commercially, with attribution.

2. How it works

1. Capture: the Sentinel-2 satellites image every point on Earth roughly every 5 days. For a requested location we pull the clearest, least-cloudy scene from each revisit window, and back-date through the free archive.
2. Processing: raw spectral bands are rendered into true-colour images (and, where useful, a vegetation-highlight view that makes green-cover change stand out). Cloudy or empty scenes are filtered out automatically.
3. Alignment: every frame is clipped to the same geographic footprint and dated with its satellite acquisition date.
4. Delivery: frames are assembled into an interactive timeline page and an on-demand evidence report. As new satellite passes arrive, the timeline keeps extending.

3. Data & coverage

4. The evidence report

From any Drishti timeline you can generate a self-contained report for record-keeping, campaigns, media or complaints. Open a timeline, set the comparison point if you want, then choose Generate Report → Print / Save as PDF. Each report contains:

• Site name, location and centre coordinates, plus the area-of-interest bounding box and approximate coverage
• The monitoring period (day one → selected date) and total duration
• The number of dated satellite observations analysed and the revisit cadence
• A before / after pair — day one versus the selected date, each labelled with its acquisition date
• A progression strip of evenly spaced milestone images
• The methodology, the Copernicus data attribution, and a disclaimer
• The date and time the report was generated

5. Accuracy & limitations

• Area-scale, not object-scale. At ~10 m per pixel, Drishti clearly shows earthworks, structures, cleared land and vegetation loss — but not fine detail such as a single tree, vehicle or person.
• Cloud cover. Heavily clouded passes are skipped, so the gap between two frames can occasionally be longer than 5 days, especially in monsoon seasons.
• Dates are acquisition dates. Each frame is labelled with the satellite's pass date, not the date of processing.
• Higher resolution. Where sharper 0.3–0.5 m detail is needed for specific milestones, commercial satellite imagery can be sourced separately (quoted per project).

6. Licensing & attribution

Drishti uses Copernicus Sentinel-2 data, which is open and free to use, reproduce and publish — including for commercial and documentary purposes — under the Copernicus Sentinel Data licence, provided the data is credited. Every Drishti timeline and report carries the required attribution:

Drishti does not rely on restricted Copernicus Contributing Mission (third-party) data, which carries non-commercial and no-resale restrictions. Any higher-resolution commercial imagery, if commissioned, is licensed directly from its provider under that provider's terms.

7. Terms of use & disclaimer

These terms apply to Drishti timelines and reports prepared by Chiramal Enterprises, and are agreed per project before work begins. (Drishti is a service, not licensed software — the licence terms for our desktop/web software products do not apply here.)

Nature of the service

Drishti provides a documentary record derived from public satellite imagery, for monitoring, awareness and record-keeping. A Drishti timeline or report is not a certified land survey, a legal boundary determination, or an official instrument, and is not a substitute for a licensed surveyor, valuer or legal advice.

Accuracy & availability

Imagery, acquisition dates and revisit frequency are determined by the Copernicus programme and are provided "as is". Coverage on any given date is subject to satellite scheduling and cloud cover, neither of which is within our control.

Permitted use

Outputs may be shared and published with the Copernicus attribution intact. When using a report as supporting evidence in any formal, regulatory or legal process, you remain responsible for confirming its suitability for that purpose.

Liability

To the extent permitted by law, Chiramal Enterprises is not liable for decisions taken on the basis of Drishti outputs. Pricing is on a per-project basis and agreed in writing before work begins.