# RISAT-1

> Indian Earth observation satellite

**Wikidata**: [Q2633139](https://www.wikidata.org/wiki/Q2633139)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/RISAT-1)  
**Source**: https://4ort.xyz/entity/risat-1

## Summary  
RISAT‑1 (Radar Imaging Satellite 1) is an Indian Earth‑observation satellite that uses synthetic‑aperture radar (SAR) to capture high‑resolution images regardless of weather or daylight. It was launched on 26 April 2012 aboard a Polar Satellite Launch Vehicle‑XL (PSLV‑XL) from the Satish Dhawan Space Centre and is operated by the Indian Space Research Organisation (ISRO).

## Key Facts  
- **Launch date:** 26 April 2012 (PSLV‑XL)【launch_date】  
- **Orbit:** Sun‑synchronous orbit, enabling consistent lighting conditions for imaging【satellite_of】  
- **Mission type:** Synthetic‑aperture radar (SAR) Earth‑observation satellite【instance_of】  
- **Operator/Owner:** Indian Space Research Organisation (ISRO)【operator】【owned_by】  
- **COSPAR ID:** 2012‑017A【cospar_id】  
- **SCN (Space‑craft Number):** 38248【scn】  
- **Launch site:** Satish Dhawan Space Centre First Launch Pad【start_point】  
- **Series:** Part of the Radar Imaging Satellite series; preceded by RISAT‑2 and followed by RISAT‑2B【part_of】【follows】【followed_by】  
- **Aliases:** Radar Imaging Satellite 1【aliases】  
- **Image (render):** https://commons.wikimedia.org/wiki/Special:FilePath/Render_of_Radar_Imaging_Satellite_RISAT-1_in_deployed_configuration.png【image】

## FAQs  
### Q: What is the primary purpose of RISAT‑1?  
A: RISAT‑1 is designed to acquire all‑weather, day‑and‑night radar images of the Earth for applications such as agriculture monitoring, disaster management, and surveillance.  

### Q: When and how was RISAT‑1 launched?  
A: The satellite was launched on 26 April 2012 aboard an Indian Polar Satellite Launch Vehicle‑XL from the Satish Dhawan Space Centre’s First Launch Pad.  

### Q: Which organization operates RISAT‑1?  
A: The Indian Space Research Organisation (ISRO) operates and owns RISAT‑1, managing its mission and data distribution.  

### Q: What orbit does RISAT‑1 use and why?  
A: RISAT‑1 resides in a Sun‑synchronous orbit, which provides consistent illumination geometry and repeat‑pass coverage, ideal for systematic Earth‑observation.  

### Q: How does RISAT‑1 differ from optical imaging satellites?  
A: Unlike optical sensors, RISAT‑1’s SAR can penetrate cloud cover and operate in darkness, delivering reliable imagery regardless of weather or lighting conditions.  

## Why It Matters  
RISAT‑1 marked a pivotal step for India’s autonomous remote‑sensing capabilities by delivering a domestically built SAR platform. Synthetic‑aperture radar enables continuous monitoring of large swaths of the Earth, crucial for agricultural forecasting, flood and cyclone assessment, and border surveillance—tasks where optical satellites falter due to cloud cover or night‑time darkness. By operating in a Sun‑synchronous orbit, RISAT‑1 provides regular, repeatable coverage, supporting both civilian and defense applications. Its successful launch and operation demonstrated India’s growing expertise in advanced radar technology, reducing reliance on foreign data sources and strengthening national security and disaster‑response frameworks. The satellite also serves as a technological foundation for subsequent RISAT missions, fostering a lineage of increasingly capable radar imaging assets.  

## Notable For  
- First Indian SAR satellite launched on a PSLV‑XL, showcasing ISRO’s launch versatility.  
- Provides all‑weather, day‑and‑night imaging, a capability absent in many contemporaneous optical Earth‑observation satellites.  
- Integrated into the Radar Imaging Satellite series, bridging earlier RISAT‑2 and later RISAT‑2B missions.  
- Operates in a Sun‑synchronous orbit, ensuring consistent revisit times for systematic monitoring.  
- Contributed to India’s strategic autonomy in high‑resolution radar data for both civilian and defense uses.  

## Body  

### Mission Overview  
RISAT‑1 (Radar Imaging Satellite 1) is a synthetic‑aperture radar (SAR) satellite built by ISRO for Earth‑observation. Its primary objectives include:  

- Agricultural assessment (crop health, acreage).  
- Disaster management (flood mapping, landslide detection).  
- Border and maritime surveillance.  

### Technical Specifications  

- **Platform:** Synthetic‑aperture radar satellite (SAR).  
- **Orbit:** Sun‑synchronous, altitude ≈ 620 km (typical for SAR missions).  
- **Imaging mode:** X‑band radar, capable of resolutions up to 1 m (publicly reported).  
- **Power:** Solar panels with battery backup (standard for ISRO LEO satellites).  

### Launch Details  

- **Vehicle:** Polar Satellite Launch Vehicle‑XL (PSLV‑XL).  
- **Date & Time:** 26 April 2012, 04:58 UTC (launch window).  
- **Site:** Satish Dhawan Space Centre First Launch Pad, Sriharikota, India.  
- **Payload:** Single SAR satellite (RISAT‑1).  

### Operational History  

- Entered service shortly after orbit insertion; began routine SAR data acquisition.  
- Data has been used by Indian agencies for crop‑yield estimation and flood‑risk mapping.  
- Continues to operate alongside newer RISAT missions, forming a constellation for persistent radar coverage.  

### Relationship to Other RISAT Satellites  

- **Predecessor:** RISAT‑2 (radar‑imaging reconnaissance satellite, re‑entered in 2022).  
- **Successor:** RISAT‑2B (launched later, extending SAR capabilities).  
- All belong to the **Radar Imaging Satellite** series, a dedicated ISRO program for radar‑based Earth observation.  

### International Context  

- RISAT‑1 placed India among a select group of nations with indigenous SAR satellites (e.g., Canada’s RADARSAT, USA’s NISAR).  
- Enhances global data sharing for climate and disaster research while preserving national security interests.  

## Schema Markup  
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{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "RISAT-1",
  "description": "Indian Earth observation satellite equipped with synthetic aperture radar, launched on 26 April 2012.",
  "sameAs": [
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  "additionalType": "SyntheticApertureRadarSatellite"
}

## References

1. [Source](https://www.isro.gov.in/launchers/list-of-pslv-launches)
2. Jonathan's Space Report
3. Freebase Data Dumps. 2013