TLE data of satellites

src/app.module.ts

@@ -24,7 +24,7 @@ import { AtcController } from './atc/atc.controller';
 import { VatsimService } from './utilities/vatsim.service';
 import { AtcService } from './atc/atc.service';
 import { IvaoService } from './utilities/ivao.service';
-import { GnssModule } from './gnss/gnss.module';
+import { SatellitesModule } from './satellites/satellites.module';
 import { CpdlcController } from './cpdlc/cpdlc.controller';
 import { CpdlcService } from './cpdlc/cpdlc.service';
 import { NotFoundExceptionFilter } from './utilities/not-found.filter';
@@ -116,7 +116,7 @@ import { NotFoundExceptionFilter } from './utilities/not-found.filter';
         AirportModule,
         GitVersionsModule,
         ChartsModule,
-        GnssModule,
+        SatellitesModule,
     ],
     controllers: [
         AppController,

src/gnss/dto/satellite-info.dto.ts → src/satellites/dto/satellite-info.dto.ts

@@ -51,4 +51,10 @@ export class SatelliteInfo {
 
     @ApiProperty()
     meanMotionDdot: number;
+
+    @ApiProperty()
+    tleLineOne: string;
+
+    @ApiProperty()
+    tleLineTwo: string;
 }

src/satellites/satellites.controller.ts

@@ -0,0 +1,43 @@
+import { ApiOkResponse, ApiQuery, ApiTags } from '@nestjs/swagger';
+import { CacheInterceptor, CacheTTL, Controller, Get, Logger, Query, UseInterceptors } from '@nestjs/common';
+import { Observable } from 'rxjs';
+import { Cron } from '@nestjs/schedule';
+import { SatellitesService } from './satellites.service';
+import { SatelliteInfo } from './dto/satellite-info.dto';
+import { CacheService } from '../cache/cache.service';
+
+@ApiTags('Satellites')
+@Controller('api/v1/satellites')
+@UseInterceptors(CacheInterceptor)
+export class SatellitesController {
+    private readonly logger = new Logger(SatellitesController.name);
+
+    constructor(
+        private service: SatellitesService,
+        private cache: CacheService,
+    ) {}
+
+    @Get()
+    @CacheTTL(3600) // 1h
+    @ApiQuery({
+        name: 'type',
+        description: 'The requested satellite type',
+        example: 'gnss',
+        required: true,
+        enum: ['gnss', 'iridium', 'iridium-NEXT', 'starlink', 'galileo', 'glo-ops', 'beidou', 'intelsat'],
+    })
+    @ApiOkResponse({ description: 'Satellite data for the requested type constellation', type: [SatelliteInfo] })
+    getGnssInfo(@Query('type') type: string): Observable<SatelliteInfo[]> {
+        return this.service.getSatellitesInfo(type);
+    }
+
+    @Cron('0 1 * * *')
+    async clearCache() {
+        try {
+            this.logger.log('Clearing GNSS cache');
+            await this.cache.del('/api/v1/satellites');
+        } catch (e) {
+            this.logger.error(e);
+        }
+    }
+}

src/satellites/satellites.module.ts

@@ -0,0 +1,10 @@
+import { HttpModule, Module } from '@nestjs/common';
+import { SatellitesService } from './satellites.service';
+import { SatellitesController } from './satellites.controller';
+
+@Module({
+    imports: [HttpModule],
+    providers: [SatellitesService],
+    controllers: [SatellitesController],
+})
+export class SatellitesModule {}

src/satellites/satellites.service.ts

@@ -0,0 +1,62 @@
+import { HttpService, Injectable, Logger } from '@nestjs/common';
+import { map, tap } from 'rxjs/operators';
+import { forkJoin, Observable } from 'rxjs';
+import { SatelliteInfo } from './dto/satellite-info.dto';
+
+@Injectable()
+export class SatellitesService {
+    private readonly logger = new Logger(SatellitesService.name);
+
+    constructor(private readonly http: HttpService) {
+    }
+
+    public getSatellitesInfo(type: string): Observable<SatelliteInfo[]> {
+        return forkJoin({
+            jsonResponse: this.http.get<any>(`https://celestrak.com/NORAD/elements/gp.php?GROUP=${type}&FORMAT=json`),
+            tleResponse: this.http.get<any>(`https://celestrak.com/NORAD/elements/gp.php?GROUP=${type}&FORMAT=tle`),
+        }).pipe(
+            tap((response) => this.logger.debug(`Response status ${response.jsonResponse.status} for Celestrak request`)),
+            tap((response) => this.logger.debug(`Response status ${response.tleResponse.status} for Celestrak request`)),
+            map((response) => [response.jsonResponse.data, response.tleResponse.data]),
+            map((data) => {
+                const satellites: SatelliteInfo[] = data[0].map((info) => ({
+                    name: info.OBJECT_NAME,
+                    id: info.OBJECT_ID,
+                    epoch: new Date(info.EPOCH),
+                    meanMotion: info.MEAN_MOTION,
+                    eccentricity: info.ECCENTRICITY,
+                    inclination: info.INCLINATION,
+                    raOfAscNode: info.RA_OF_ASC_NODE,
+                    argOfPericenter: info.ARG_OF_PERICENTER,
+                    meanAnomaly: info.MEAN_ANOMALY,
+                    ephemerisType: info.EPHEMERIS_TYPE,
+                    classificationType: info.CLASSIFICATION_TYPE,
+                    noradCatId: info.NORAD_CAT_ID,
+                    elementSetNo: info.ELEMENT_SET_NO,
+                    revAtEpoch: info.REV_AT_EPOCH,
+                    bstar: info.BSTAR,
+                    meanMotionDot: info.MEAN_MOTION_DOT,
+                    meanMotionDdot: info.MEAN_MOTION_DDOT,
+                    tleLineOne: '',
+                    tleLineTwo: '',
+                }));
+
+                const tleData: string[] = data[1].split('\n');
+                for (let i = 0; i < tleData.length; i += 3) {
+                    const name = tleData[i].trim();
+                    if (name.length === 0) continue;
+
+                    const idx = satellites.findIndex((satellite) => satellite.name === name);
+                    if (idx > -1) {
+                        satellites[idx].tleLineOne = tleData[i + 1].trim();
+                        satellites[idx].tleLineTwo = tleData[i + 2].trim();
+                    } else {
+                        this.logger.warn(`Unable to find ${name}, ${tleData[i]}`);
+                    }
+                }
+
+                return satellites;
+            }),
+        );
+    }
+}