Access Commands
The access command group calculates when satellites are visible from ground locations, considering elevation constraints and other visibility criteria.
Commands
compute
Compute satellite access windows for a ground location.
Syntax:
| brahe access compute <NORAD_ID> [OPTIONS]
|
Arguments: - NORAD_ID - NORAD catalog ID of the satellite (integer)
Location Options (choose one):
Location coordinates: - --lat <degrees> - Latitude in degrees (-90 to 90) - --lon <degrees> - Longitude in degrees (-180 to 180) - --alt <meters> - Altitude above WGS84 ellipsoid (default: 0.0)
Or ground station lookup: - --gs-provider <name> - Ground station provider (e.g., 'ksat', 'atlas', 'aws') - --gs-name <name> - Ground station name to lookup
Time Range Options:
--start-time <epoch> - Start time (ISO-8601). Default: now--end-time <epoch> - End time (ISO-8601)--duration <days> - Duration in days (default: 7)
Constraint Options:
--min-elevation <degrees> - Minimum elevation angle (default: 10.0)
Output Options:
--output-format [table|rich|simple] - Output format (default: table)--sort-by [contact_number|start_time|end_time|duration|max_elevation|start_azimuth|end_azimuth] - Sort field (default: start_time)--sort-order [ascending|descending] - Sort order (default: ascending)--max-results <count> - Maximum number of windows to display--output-file <path> - Export results to JSON file
Examples:
ISS passes over New York City (next 7 days):
| brahe access compute 25544 --lat 40.7128 --lon -74.0060
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| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 18 access window(s)
...
|
GPS satellite passes (15° minimum elevation):
| brahe access compute 32260 --lat 40.7128 --lon -74.0060 --min-elevation 15
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| # Access Windows for NAVSTAR 60 (USA 196) (NORAD ID: 32260)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 15.0°
# Found 8 access window(s)
|
Custom time range:
| brahe access compute 25544 --lat 40.7128 --lon -74.0060 \
--start-time "2024-06-01T00:00:00Z" \
--duration 1
|
| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 2 access window(s)
|
Use ground station database:
| brahe access compute 25544 --gs-provider ksat --gs-name "Svalbard"
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| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 78.2300° lat, 15.4100° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 19 access window(s)
|
Simple output format:
| brahe access compute 25544 --lat 40.7128 --lon -74.0060 --output-format simple
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| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 18 access window(s)
# 1. 2025-11-03 18:36:18.197 UTC | 2025-11-03 18:38:16.000 UTC | 1m 57s | Max Elev: 11.9° | Az: 150°-114°
# 2. 2025-11-03 20:11:37.226 UTC | 2025-11-03 20:16:16.000 UTC | 4m 38s | Max Elev: 20.6° | Az: 255°-351°
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Export to JSON:
| brahe access compute 25544 --lat 40.7128 --lon -74.0060 --output-file passes.json
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| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 18 access window(s)
|
Sort by maximum elevation (highest first):
| brahe access compute 25544 --lat 40.7128 --lon -74.0060 \
--sort-by max_elevation --sort-order descending --max-results 5
|
| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 5 access window(s)
# ┏━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┓
# ┃ ┃ Start ┃ End ┃ ┃ Max ┃ Start ┃ ┃
# ┃ Contact ┃ Time ┃ Time ┃ ┃ Elev ┃ Az ┃ End Az ┃
# ┃ # ┃ (UTC) ┃ (UTC) ┃ Durati… ┃ (deg) ┃ (deg) ┃ (deg) ┃
# ┡━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━╇━━━━━━━━━╇━━━━━━━━╇━━━━━━━━━╇━━━━━━━━┩
# │ 1 │ 2025-1… │ 2025-… │ 6 │ 77.0 │ 321 │ 148 │
# │ │ 05:22:… │ 05:28… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 31.74 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# │ 2 │ 2025-1… │ 2025-… │ 6 │ 69.8 │ 319 │ 151 │
# │ │ 06:58:… │ 07:04… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 30.04 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# │ 3 │ 2025-1… │ 2025-… │ 6 │ 57.9 │ 206 │ 46 │
# │ │ 18:34:… │ 18:40… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 7.79 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# │ 4 │ 2025-1… │ 2025-… │ 6 │ 52.9 │ 204 │ 48 │
# │ │ 16:58:… │ 17:04… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 9.76 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# │ 5 │ 2025-1… │ 2025-… │ 5 │ 52.6 │ 227 │ 22 │
# │ │ 17:46:… │ 17:52… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 59.45 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# └─────────┴─────────┴────────┴─────────┴────────┴─────────┴────────┘
|
Sort by duration (longest passes first):
| brahe access compute 25544 --lat 40.7128 --lon -74.0060 \
--sort-by duration --sort-order descending
|
| # Access Windows for ISS (ZARYA) (NORAD ID: 25544)
# Location: 40.7128° lat, -74.0060° lon, 0 m alt
# Minimum elevation: 10.0°
# Found 18 access window(s)
# ┏━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┓
# ┃ ┃ Start ┃ End ┃ ┃ Max ┃ Start ┃ ┃
# ┃ Contact ┃ Time ┃ Time ┃ ┃ Elev ┃ Az ┃ End Az ┃
# ┃ # ┃ (UTC) ┃ (UTC) ┃ Durati… ┃ (deg) ┃ (deg) ┃ (deg) ┃
# ┡━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━╇━━━━━━━━━╇━━━━━━━━╇━━━━━━━━━╇━━━━━━━━┩
# │ 1 │ 2025-1… │ 2025-… │ 6 │ 53.8 │ 204 │ 47 │
# │ │ 16:58:… │ 17:05… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# │ │ │ │ 24.76 │ │ │ │
# │ │ │ │ seconds │ │ │ │
# │ 2 │ 2025-1… │ 2025-… │ 6 │ 59.5 │ 206 │ 45 │
# │ │ 18:34:… │ 18:41… │ minutes │ │ │ │
# │ │ UTC │ UTC │ and │ │ │ │
# └─────────┴─────────┴────────┴─────────┴────────┴─────────┴────────┘
|
Tips
NORAD Catalog IDs
Find NORAD IDs using the datasets command:
| # Search for satellite by name
brahe datasets celestrak lookup "ISS"
# Show TLE with NORAD ID
brahe datasets celestrak show 25544
|
See Datasets CLI for more details.
Negative Longitudes
For westerly longitudes, use negative values with = or --:
| # Method 1: Negative longitude
brahe access compute 25544 --lat 40.7128 --lon=-74.0060
# Method 2: After -- separator
brahe access compute 25544 -- --lat 40.7128 --lon -74.0060
|
table (default): - ASCII table with columns - Good for terminal viewing - Aligned columns
rich: - Enhanced table with colors - Better readability in modern terminals
simple: - Plain text, one line per pass - Easy to parse with scripts
JSON (via --output-file): - Machine-readable - Complete data structure - For further processing
Computing access windows requires: 1. Downloading TLE data from CelesTrak (cached) 2. Downloading EOP data (cached) 3. Propagating orbit over time range
Longer durations take more time: - 1 day: ~1-2 seconds - 7 days: ~5-10 seconds - 30 days: ~20-30 seconds
See Also