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Find answers to common questions, get set up quickly, or send us a message. Most questions are answered in the FAQ below.
Quick links
Getting Started
Set up your first Area of Interest and get your first alert in minutes.
API Reference
Full REST API docs with examples for every endpoint.
FAQ
Answers to the most common questions about plans, data, and alerts.
System Status
Live health of the API, database, worker, and tile server.
Changelog
Every release, feature, fix, and improvement since launch.
Contact Us
Can't find what you need? Our team responds within 24 hours.
Getting started
1
Create an account
Sign up at /signup. The Free plan gives you one Area of Interest with weekly Sentinel-2 scans — no credit card required.
2
Draw your Area of Interest (AOI)
In the Dashboard, click New AOI. Draw a polygon on the map or paste GeoJSON coordinates. Name it and choose your scan frequency. Maximum AOI size is 200 km² on Free, 1,000 km² on Starter, 2,000 km² on Growth, 3,000 km² on Pro, and up to 150,000 km² on Enterprise (based on coverage tier).
3
Choose what to detect
Select change types to watch: Deforestation, Construction, Flooding, Fire / Burn Scar, Vegetation Loss, or Urban Expansion. Multiple types can be enabled per AOI.
4
Configure alert delivery
Under Settings → Account, add a webhook URL or confirm your email address. Alerts fire within 30 minutes of a new Sentinel-2 scene becoming available for your region (daily on Starter and Pro).
5
Use the API (Pro & Enterprise)
Generate an API key under Settings → API. All REST endpoints are documented at api.terralert.io/docs. Authentication:
Authorization: Bearer <token>.Frequently asked questions
What satellite data does TerrAlert use?
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TerrAlert ingests Sentinel-2 Level-2A (10 m/pixel, 5-day revisit globally) and Landsat 9 Level-2 (30 m/pixel, 16-day revisit) via the EODAG library. Both datasets are freely available from Copernicus and USGS — there is no data licensing cost passed to you.
How accurate are the change detections?
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No single model is treated as ground truth. Every alert is checked against independent, authoritative signal sources before it reaches you — NASA FIRMS active-fire detections and GLAD/RADD deforestation alerts corroborate our optical change-detection model's output. Confidence scores are provided with every detection so you can judge for yourself; we recommend treating corroborated detections (flagged as such) with the highest confidence, and scores below 50% are filtered out before delivery.
How often will I receive alerts?
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Alert frequency depends on your plan:
Free — Weekly scan (every 7 days)
Starter — Daily scan (every 24 hours)
Pro — Daily scan with API trigger support
Enterprise — Real-time (triggered on each new scene, typically every 2–5 days depending on region and cloud cover)
Free — Weekly scan (every 7 days)
Starter — Daily scan (every 24 hours)
Pro — Daily scan with API trigger support
Enterprise — Real-time (triggered on each new scene, typically every 2–5 days depending on region and cloud cover)
What happens when there is cloud cover?
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Scenes with >30% cloud cover over your AOI are automatically skipped. The pipeline picks the next available clear scene. During persistent cloud cover (e.g. monsoon season) you may see gaps of 2–4 weeks. This is a fundamental limitation of optical satellite imagery — radar-based SAR data is on our roadmap.
Can I monitor areas anywhere on Earth?
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Yes. Sentinel-2 covers all land surface between 84°N and 56°S. You can draw an AOI anywhere within that range. Arctic and Antarctic regions have limited coverage. Large ocean areas are supported for coastal monitoring.
How do I upgrade or downgrade my plan?
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Go to Settings → Plans inside the dashboard and click Upgrade on your target plan. Billing is handled by Stripe — upgrades take effect immediately (prorated), downgrades take effect at the end of your billing period. To cancel, click Cancel Plan in Settings → Billing and your data is retained for 30 days.
Is my data stored securely? Where is it processed?
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AOI geometry and detection metadata are stored in a PostgreSQL database. Raw satellite imagery (COG format) is stored in AWS S3 and accessed via signed URLs — never publicly exposed. All data is encrypted at rest and in transit (TLS 1.3). We are GDPR-compliant — see our Privacy Policy and the GDPR data export tool under Settings → Account.
How do webhooks work?
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Under Settings → Account, add a webhook URL and a signing secret (minimum 16 characters). When a detection fires, TerrAlert sends an HTTP POST to your URL with a JSON payload and an
X-TerrAlert-Signature HMAC-SHA256 header. Failed deliveries are retried up to 5 times with exponential backoff. The full payload schema is in the API docs.
What do I do if I'm not receiving alerts?
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Check these in order:
1. Visit /status — confirm all services are operational
2. Check Settings → Account — confirm your email address is verified
3. Check the Alerts tab in the dashboard — alerts may have been sent but marked as read
4. For webhooks, check your endpoint's HTTP response code — we expect 200–299
5. Check cloud cover for your region — scenes may have been skipped
If none of the above resolve it, contact support with your AOI ID.
1. Visit /status — confirm all services are operational
2. Check Settings → Account — confirm your email address is verified
3. Check the Alerts tab in the dashboard — alerts may have been sent but marked as read
4. For webhooks, check your endpoint's HTTP response code — we expect 200–299
5. Check cloud cover for your region — scenes may have been skipped
If none of the above resolve it, contact support with your AOI ID.
Do you have an Enterprise / custom plan?
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Yes. Enterprise plans include unlimited AOIs, real-time processing, custom data retention, dedicated support, SSO, and white-label options. Contact us with your use case and estimated AOI count — we'll put together a custom quote within 2 business days.
Service Level Agreement
| Plan | Uptime SLA | Support Response | Alert Delivery | Data Retention |
|---|---|---|---|---|
| Free | Best effort | Community / email (5 business days) | Best effort · 30 min after scene | 30 days |
| Starter | 99.5% | Email (2 business days) | ≤ 30 min after scene | 183 days (6 months) |
| Pro | 99.9% | Email (1 business day) | ≤ 15 min after scene | 1,095 days (3 years) |
| Enterprise | 99.95% | Dedicated CSM · 4 h response | ≤ 5 min after scene | Unlimited (custom) |
Contact support
Send us a message
We read every message and respond within 1–2 business days. For urgent issues (data loss, billing errors), mark your topic as Critical and we'll prioritise.