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a4b5ecb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | """Cross-reference detected maneuvers with Space-Track.org CDM data.
Queries the CDM_PUBLIC class for recent conjunction data messages
involving maneuvered satellites. CDM confirmation is the strongest
signal that a maneuver was collision-avoidance.
Requires SPACETRACK_USER and SPACETRACK_PASS environment variables.
Fails silently if credentials are not set (purely enrichment).
"""
import os
import json
import time
import requests
from pathlib import Path
from datetime import datetime, timedelta, timezone
# Rate limiting: max 30 requests/min to Space-Track
MAX_REQUESTS_PER_MIN = 30
BATCH_SIZE = 100 # Max NORAD IDs per query
CACHE_EXPIRY_DAYS = 7
SPACETRACK_BASE = "https://www.space-track.org"
LOGIN_URL = f"{SPACETRACK_BASE}/ajaxauth/login"
CDM_QUERY_URL = f"{SPACETRACK_BASE}/basicspacedata/query/class/cdm_public"
def _get_credentials() -> tuple[str, str]:
"""Get Space-Track credentials from environment."""
user = os.environ.get("SPACETRACK_USER", "")
passwd = os.environ.get("SPACETRACK_PASS", "")
return user, passwd
def _load_cache(cache_path: Path) -> dict:
"""Load CDM cache, filtering expired entries."""
if not cache_path.exists():
return {}
try:
with open(cache_path) as f:
cache = json.load(f)
except (json.JSONDecodeError, IOError):
return {}
# Filter expired entries
cutoff = (datetime.now(timezone.utc) - timedelta(days=CACHE_EXPIRY_DAYS)).isoformat()
return {
k: v for k, v in cache.items()
if v.get("cached_at", "") > cutoff
}
def _save_cache(cache: dict, cache_path: Path):
"""Save CDM cache to disk."""
cache_path.parent.mkdir(parents=True, exist_ok=True)
with open(cache_path, "w") as f:
json.dump(cache, f, indent=2)
def check_cdm_for_norad_ids(
norad_ids: list[int],
lookback_days: int = 7,
min_pc: float = 1e-7,
cache_dir: Path = None,
) -> dict[int, list[dict]]:
"""Query Space-Track CDM_PUBLIC for recent CDMs involving given satellites.
Args:
norad_ids: NORAD catalog IDs to check.
lookback_days: How far back to search for CDMs.
min_pc: Minimum probability of collision to include.
cache_dir: Directory for CDM cache file. Defaults to data/prediction_logs/.
Returns:
Map of norad_id -> list of CDM records with PC, TCA, MISS_DISTANCE.
Empty dict if credentials not set or query fails.
"""
user, passwd = _get_credentials()
if not user or not passwd:
return {}
if cache_dir is None:
cache_dir = Path(__file__).parent.parent.parent / "data" / "prediction_logs"
cache_path = cache_dir / "cdm_cache.json"
cache = _load_cache(cache_path)
# Check which IDs need fresh queries
results = {}
uncached_ids = []
for nid in norad_ids:
key = str(nid)
if key in cache:
results[nid] = cache[key].get("cdms", [])
else:
uncached_ids.append(nid)
if not uncached_ids:
return results
# Authenticate with Space-Track
try:
session = requests.Session()
resp = session.post(LOGIN_URL, data={
"identity": user,
"password": passwd,
}, timeout=30)
resp.raise_for_status()
except Exception as e:
print(f" Space-Track login failed: {e}")
return results
# Query in batches
now_str = datetime.now(timezone.utc).strftime("%Y-%m-%d")
lookback_str = (datetime.now(timezone.utc) - timedelta(days=lookback_days)).strftime("%Y-%m-%d")
for batch_start in range(0, len(uncached_ids), BATCH_SIZE):
batch = uncached_ids[batch_start:batch_start + BATCH_SIZE]
ids_str = ",".join(str(nid) for nid in batch)
query_url = (
f"{CDM_QUERY_URL}"
f"/SAT1_NORAD_CAT_ID/{ids_str}"
f"/TCA/>{lookback_str}"
f"/orderby/TCA desc"
f"/format/json"
)
try:
resp = session.get(query_url, timeout=60)
resp.raise_for_status()
cdm_records = resp.json()
except Exception as e:
print(f" Space-Track CDM query failed: {e}")
# Cache empty results for failed IDs to avoid re-querying
for nid in batch:
cache[str(nid)] = {
"cdms": [],
"cached_at": datetime.now(timezone.utc).isoformat(),
}
continue
# Process CDM records
batch_results: dict[int, list[dict]] = {nid: [] for nid in batch}
for cdm in cdm_records:
try:
pc = float(cdm.get("PC", 0) or 0)
if pc < min_pc:
continue
sat1_id = int(cdm.get("SAT1_NORAD_CAT_ID", 0))
record = {
"tca": cdm.get("TCA", ""),
"pc": pc,
"miss_distance_km": float(cdm.get("MISS_DISTANCE", 0) or 0) / 1000.0,
"sat1_name": cdm.get("SAT1_NAME", ""),
"sat2_name": cdm.get("SAT2_NAME", ""),
"sat2_norad": int(cdm.get("SAT2_NORAD_CAT_ID", 0) or 0),
}
if sat1_id in batch_results:
batch_results[sat1_id].append(record)
except (ValueError, TypeError):
continue
# Update cache and results
for nid in batch:
cdms = batch_results.get(nid, [])
results[nid] = cdms
cache[str(nid)] = {
"cdms": cdms,
"cached_at": datetime.now(timezone.utc).isoformat(),
}
# Rate limiting between batches
if batch_start + BATCH_SIZE < len(uncached_ids):
time.sleep(60.0 / MAX_REQUESTS_PER_MIN)
# Save updated cache
_save_cache(cache, cache_path)
return results
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