Search result for:  id10=WA 0812 2782 5310 [[Pandawa KacaFilm]] Supplier Solar Control Film Terdekat Surakarta

The Geometry GUI provides a graphical representation of your survey, along with a wide range of Control capability. It is particularly useful when conducting reflection surveys, but can be useful in a wide range of applications. It summarizes, in one simple view, the physical positions and other attributes of the hardware on the ground, and allows graphical Control of these. Below is a typical display of a 96-channel, four-Geode layout. We will first describe the display itself, and follow with a description of its Control capabilities. Example Geometry GUI

The Earth's magnetic field changes throughout the day due to Solar wind and other factors. A base station's data is used to correct for these variations (diurnal variations), which can significantly impact the results of a survey. In general, diurnal variations do not change rapidly, and it is not required to record the Earth's magnetic field at high sample rates. However, during geomagnetic storms, diurnal variations can be so rapid that 10Hz or a higher sample rate is necessary to track the field change. Kp index is commonly used to measure the strength of geomagnetic activity. The diurnal variation on October 11th 2024, when the Kp index reached above 8, was shown in the plot below. Field changes as fast as 5nT/second were recorded. In comparison, the Kp index on October 15th was around 4. The diurnal variation was much slower. Sometimes if a survey site is close to man-made structures, such as railways, very rapid local magnetic field variations can also occur due to electrical current activities. A high sample rate magnetometer base station is also required in these situations, as well as some expertise in setting up the base station.

Your need of a magnetometer base station like the G-862RBS depends on the objective of the survey. If one is performing a geologic survey to investigate deep structure (exploration for mineral deposits, oil/gas, geology) then the wavelengths of the "target" body are typically “long” (long in meters, therefore long in data acquisition time). The rate at which the Earth's natural magnetic field responds to interaction with the Solar wind is also typically many seconds to minutes (diurnal variations). Since the geologic and diurnal variations are of similar wavelengths, a geologic mag survey usually requires a base station. Please read the introductory sections of the Applications Manual for Portable Magnetometers offered on our website for more details. If you are moving fast (fast in the sense of a brisk walk, ~1m/s) and looking for small targets (UXO, archaeological artifacts, environmental targets like drums, pipes, etc.) then you are “up and over” them in a matter of seconds and typically the earth’s field does not change in this time frame. So there is less need for a base station for these type surveys. Of course, it never hurts to have a base station running and if you are surveying over multiple days, having a reference station will allow easier “block leveling” of multiple day surveys.

If you are looking for natural magnetotelluric (MT) frequencies that are nearly always observable then you can count on the Schumann resonances. You can assume very low signal strength in the low micro Volt range. The foundational Schumann Resonance is the strongest at 7.83 Hz (around 8Hz) and it generally has a strength measured around 1 microV/root Hz in the San Francisco Bay Area. The Schumann and other lightening generated frequencies are propagated into the atmosphere, the atmosphere acting as a wave guide due to the electromagnetic signal reflecting off the ionosphere. As electromagnetic waves interact with the Earth’s surface they act as displacement currents going vertically into the Earth. These displacement currents then create secondary currents that flow horizontally in the Earth. MT signals are assumed to be plane waves since the source is far enough away to be several skin depths distant. The assumption of plane wave and multiple polarizations of the signal allows magnetotelluric calculations to be made without consideration of the source parameters. The general MT signals will come and go depending on atmospheric conditions, time of day, time of year, location, and general distant lightning activity. Signals below about 0.1 Hz are typically from the ionosphere, generated by variations in the Solar winds and how they press on the ionosphere, and not by lightning strikes. Traditional deep MT measurements will use natural magnetotelluric signals from 0.001 Hz (1,000 second period) and even lower frequencies with instruments that are capable. The dominant Schumann Resonant frequencies are 7.83Hz, 14.3, 20.8, 27.3, and 30.8Hz. There exist a magnetotelluric “dead-zone” in the 800 Hz to 4 kHz range, and this dead-zone is the result of certain frequencies not being contained in the atmospheric wave guide, instead simply dissipating into space. If you are working with AMT measurements generally the limit is somewhere between 0.1 Hz to around 2 Hz but that is because of instrumentation not the existence of the fields. The Stratagem EH4 went to 10 Hz and the Geode EM3D goes to 0.1 Hz. All the power line harmonics of 60 Hz in North America and 50 Hz in other parts of the world will give strong signal but are considered noise as far as MT measurements go and need to be avoided and filtered out. Another noise problem are the world-wide very low frequency (VLF) signals that also need to be filter and avoided. VLF signals are military signals from stations around the world and they swamp out the much lower natural magnetotelluric fields. There is a geophysical method that actually uses the man-made VLF signal to detect linear conductive geologic structures but VLF are a problem for MT measurements. For more information on the Schumann Resonances, which are the predominant natural magnetotelluric currents that exist, watch the video by Geophysicist Stefan Burns below:

Hi All,   We are using the Teensy 4.1 as a logger (Adafruit GPS is linked with the Teensy) for the MFAM SX. Below is the code for the Arduino IDE (Teensy), for people who might find it useful, Roi   #include <NativeEthernet.h> #include <SD.h> // ---- NETWORK CONFIGURATION ---- byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; IPAddress ip(192, 168, 2, 10); IPAddress mfamIP(192, 168, 2, 2); uint16_t mfamPort = 1000; EthernetClient client; // ---- PACKET STRUCTURE ---- const int PACKET_SIZE = 1380; const int SAMPLE_SIZE = 32; const int HEADER_SIZE = 16; const int NUM_SAMPLES = 40; const int SD_CHIP_SELECT = BUILTIN_SDCARD; uint8_t buffer[PACKET_SIZE]; int bufferPos = 0; // ---- SD CARD ---- File logFile; bool sdReady = false; unsigned long sampleCount = 0; unsigned long fileStartTime = 0; char filename[32]; // ---- AUXILIARY CHANNEL STORAGE ---- double gyroX = 0, gyroY = 0, gyroZ = 0, gyroT = 0; double accelX = 0, accelY = 0, accelZ = 0, accelT = 0; double compassX = 0, compassY = 0, compassZ = 0, compassT = 0; // ---- GPS FROM ADAFRUIT MODULE ON SERIAL1 (Pin 0 = RX) ---- char gpsBuffer[256]; int gpsBufferPos = 0; char gpsString[128] = ""; char gpsDate[12] = "00/00/00"; char gpsTime[16] = "00:00:00.000"; bool gpsFix = false; uint8_t tsStatus = 0; // ---- OUTPUT Control ---- // Set to 1 to log every sample, 10 for 100Hz, 20 for 50Hz, etc. const int DOWNSAMPLE_FACTOR = 1; // 50 Hz output int downsampleCounter = 0; // How many minutes per file. Set to 10, 20, 60, etc. const int FILE_MINUTES = 10; // ---- LED INDICATOR ---- // Off = starting up // Very slow blink (every 3 sec) = connected and logging // Fast blink (4/sec) = connected but no data arriving // Solid on = no SD card // 3 quick flashes then pause = cannot connect to MFAM const int LED_PIN = 13; unsigned long lastBlinkTime = 0; bool ledState = false; unsigned long lastDataTime = 0; // ---- FUNCTION PROTOTYPES ---- void createNewFile(); void parsePacket(uint8_t* pkt); void parseAuxChannels(uint8_t* sample, uint16_t frameID); void readGPS(); void parseGPRMC(char* sentence); void writeSample(unsigned long timestamp, uint16_t fiducial, double mag1, uint16_t mag1s, double mag2, uint16_t mag2s, uint16_t sysStatus); int16_t toSigned16(uint16_t val); void createNewFile() { static int fileNumber = 0; // On first call, find the next available file number if (fileNumber == 0) { char testName[32]; for (int i = 1; i <= 99999; i++) { snprintf(testName, sizeof(testName), "MFAM_%05d.txt", i); if (!SD.exists(testName)) { fileNumber = i - 1; // Will be incremented below break; } } } fileNumber++; snprintf(filename, sizeof(filename), "MFAM_%05d.txt", fileNumber); logFile = SD.open(filename, FILE_WRITE); if (logFile) { logFile.println("Mag 1,Mag 2,Fid,SysS,Mg1S,Mg2S,Gyro X,Gyro Y,Gyro Z,Gyro T,Accel X,Accel Y,Accel Z,Accel T,CompassX,CompassY,CompassZ,Comp T,Date,Time,TS Status,GPS"); logFile.flush(); fileStartTime = millis(); Serial.print("Logging to: "); Serial.println(filename); } else { Serial.print("ERROR: Could not create "); Serial.println(filename); } } void setup() { Serial.begin(115200); delay(2000); // Start GPS serial port (Adafruit Ultimate GPS defaults to 9600 baud) Serial1.begin(9600); pinMode(LED_PIN, OUTPUT); digitalWrite(LED_PIN, LOW); memset(gpsString, 0, sizeof(gpsString)); // Initialize SD card if (SD.begin(SD_CHIP_SELECT)) { sdReady = true; Serial.println("SD card ready."); } else { Serial.println("WARNING: No SD card found. Serial output only."); digitalWrite(LED_PIN, HIGH); } // Initialize Ethernet Ethernet.begin(mac, ip); if (Ethernet.hardwareStatus() == EthernetNoHardware) { Serial.println("ERROR: No Ethernet hardware found!"); while (true) {} } Serial.print("Teensy IP: "); Serial.println(Ethernet.localIP()); Serial.print("Connecting to MFAM at "); Serial.print(mfamIP); Serial.print(":"); Serial.println(mfamPort); if (client.connect(mfamIP, mfamPort)) { Serial.println("Connected to MFAM!"); } else { Serial.println("Connection failed!"); } Serial.println("Waiting for GPS fix..."); if (sdReady) { createNewFile(); } Serial.println("Mag 1,Mag 2,Fid,SysS,Mg1S,Mg2S,Gyro X,Gyro Y,Gyro Z,Gyro T,Accel X,Accel Y,Accel Z,Accel T,CompassX,CompassY,CompassZ,Comp T,Date,Time,TS Status,GPS"); } void loop() { // Always read GPS data from Serial1 readGPS(); if (!client.connected()) { Serial.println("Disconnected. Reconnecting..."); if (sdReady && logFile) { logFile.flush(); } for (int i = 0; i < 3; i++) { digitalWrite(LED_PIN, HIGH); delay(100); digitalWrite(LED_PIN, LOW); delay(100); } delay(1400); client.connect(mfamIP, mfamPort); if (client.connected()) { lastDataTime = millis(); } return; } while (client.available()) { buffer[bufferPos] = client.read(); bufferPos++; if (bufferPos >= PACKET_SIZE) { parsePacket(buffer); bufferPos = 0; lastDataTime = millis(); } } // LED patterns if (sdReady) { if (millis() - lastDataTime > 3000) { if (millis() - lastBlinkTime > 125) { ledState = !ledState; digitalWrite(LED_PIN, ledState ? HIGH : LOW); lastBlinkTime = millis(); } } else { if (millis() - lastBlinkTime > 1500) { ledState = !ledState; digitalWrite(LED_PIN, ledState ? HIGH : LOW); lastBlinkTime = millis(); } } } // New file every FILE_MINUTES minutes if (sdReady && logFile && (millis() - fileStartTime > (unsigned long)FILE_MINUTES * 60UL * 1000UL)) { logFile.close(); createNewFile(); } } // ---- GPS READING FROM ADAFRUIT MODULE ON SERIAL1 ---- void readGPS() { while (Serial1.available()) { char c = Serial1.read(); if (c == '$') { gpsBufferPos = 0; } if (gpsBufferPos < (int)sizeof(gpsBuffer) - 1) { gpsBuffer[gpsBufferPos] = c; gpsBufferPos++; } if (c == '\n' || c == '\r') { gpsBuffer[gpsBufferPos] = '\0'; if (strncmp(gpsBuffer, "$GPRMC", 6) == 0 || strncmp(gpsBuffer, "$GNRMC", 6) == 0) { // Save full sentence for logging strncpy(gpsString, gpsBuffer, sizeof(gpsString) - 1); gpsString[sizeof(gpsString) - 1] = '\0'; // Remove trailing newline/carriage return int slen = strlen(gpsString); while (slen > 0 && (gpsString[slen - 1] == '\n' || gpsString[slen - 1] == '\r')) { gpsString[slen - 1] = '\0'; slen--; } parseGPRMC(gpsBuffer); } gpsBufferPos = 0; } } } void parseGPRMC(char* sentence) { // $GPRMC,HHMMSS.sss,A,lat,N,lon,W,speed,course,DDMMYY,... char copy[256]; strncpy(copy, sentence, sizeof(copy) - 1); copy[sizeof(copy) - 1] = '\0'; char* token = strtok(copy, ","); int field = 0; while (token != NULL && field < 10) { switch (field) { case 1: // Time if (strlen(token) >= 6) { snprintf(gpsTime, sizeof(gpsTime), "%c%c:%c%c:%s", token[0], token[1], token[2], token[3], token + 4); } break; case 2: // Fix status gpsFix = (token[0] == 'A'); break; case 9: // Date if (strlen(token) >= 6) { snprintf(gpsDate, sizeof(gpsDate), "%c%c/%c%c/%c%c", token[0], token[1], token[2], token[3], token[4], token[5]); } break; } token = strtok(NULL, ","); field++; } // Update GPS bits of tsStatus tsStatus = (tsStatus & 0x0C); // Keep MFAM PPS bits (3,2) tsStatus |= 0x01; // Bit 0: RMC sentence received if (gpsFix) { tsStatus |= 0x02; // Bit 1: GPS fix valid } } // ---- MFAM DATA PARSING ---- int16_t toSigned16(uint16_t val) { if (val > 32767) return (int16_t)(val - 65536); return (int16_t)val; } void parseAuxChannels(uint8_t* sample, uint16_t frameID) { uint8_t auxID = (frameID >> 11) & 0x07; uint16_t aux0 = sample[16] | (sample[17] << 8); uint16_t aux1 = sample[18] | (sample[19] << 8); uint16_t aux2 = sample[20] | (sample[21] << 8); uint16_t aux3 = sample[22] | (sample[23] << 8); switch (auxID) { case 1: compassX = toSigned16(aux0) / 0.01333333; compassY = toSigned16(aux1) / 0.01333333; compassZ = toSigned16(aux2) / 0.01333333; compassT = toSigned16(aux3) / 128.0 + 25.0; break; case 2: gyroX = toSigned16(aux0) / 16.384; gyroY = toSigned16(aux1) / 16.384; gyroZ = toSigned16(aux2) / 16.384; gyroT = toSigned16(aux3) / 512.0 + 23.0; break; case 4: accelX = toSigned16(aux0) / 16384.0; accelY = toSigned16(aux1) / 16384.0; accelZ = toSigned16(aux2) / 16384.0; accelT = toSigned16(aux3) / 512.0 + 23.0; break; default: break; } } void writeSample(unsigned long timestamp, uint16_t fiducial, double mag1, uint16_t mag1s, double mag2, uint16_t mag2s, uint16_t sysStatus) { char tsStr[12]; snprintf(tsStr, sizeof(tsStr), "%d%d%d%d%d%d%d%d", (tsStatus >> 7) & 1, (tsStatus >> 6) & 1, (tsStatus >> 5) & 1, (tsStatus >> 4) & 1, (tsStatus >> 3) & 1, (tsStatus >> 2) & 1, (tsStatus >> 1) & 1, tsStatus & 1); char sysHex[8], m1sHex[8], m2sHex[8]; snprintf(sysHex, sizeof(sysHex), "%04X", sysStatus); snprintf(m1sHex, sizeof(m1sHex), "%04X", mag1s); snprintf(m2sHex, sizeof(m2sHex), "%04X", mag2s); char line[512]; snprintf(line, sizeof(line), "%10.4f,%10.4f,%4d,%s,%s,%s,%10.2f,%10.2f,%10.2f,%5.1f,%8.5f,%8.5f,%8.5f,%5.1f,%8.1f,%8.1f,%8.1f,%5.1f,%s,%s,%s,%s", mag1, mag2, fiducial, sysHex, m1sHex, m2sHex, gyroX, gyroY, gyroZ, gyroT, accelX, accelY, accelZ, accelT, compassX, compassY, compassZ, compassT, gpsDate, gpsTime, tsStr, gpsString); if (sdReady && logFile) { logFile.println(line); if (sampleCount % 1000 == 0) { logFile.flush(); } } if (sampleCount % 500 == 0) { Serial.println(line); } } void parsePacket(uint8_t* pkt) { // Get PPS bits from MFAM system status uint16_t firstSysStatus = pkt[HEADER_SIZE + 2] | (pkt[HEADER_SIZE + 3] << 8); uint8_t mfamPPSbits = (firstSysStatus >> 12) & 0x0C; tsStatus = (tsStatus & 0x03) | mfamPPSbits; for (int i = 0; i < NUM_SAMPLES; i++) { int offset = HEADER_SIZE + (i * SAMPLE_SIZE); uint16_t frameID = pkt[offset] | (pkt[offset + 1] << 8); uint16_t fiducial = frameID & 0x07FF; uint16_t sysStatus = pkt[offset + 2] | (pkt[offset + 3] << 8); uint32_t mag1raw = pkt[offset + 4] | (pkt[offset + 5] << 8) | ((uint32_t)pkt[offset + 6] << 16) | ((uint32_t)pkt[offset + 7] << 24); double mag1 = mag1raw * 0.05 / 1000.0; uint16_t mag1status = pkt[offset + 8] | (pkt[offset + 9] << 8); uint32_t mag2raw = pkt[offset + 10] | (pkt[offset + 11] << 8) | ((uint32_t)pkt[offset + 12] << 16) | ((uint32_t)pkt[offset + 13] << 24); double mag2 = mag2raw * 0.05 / 1000.0; uint16_t mag2status = pkt[offset + 14] | (pkt[offset + 15] << 8); parseAuxChannels(pkt + offset, frameID); sampleCount++; downsampleCounter++; if (downsampleCounter >= DOWNSAMPLE_FACTOR) { downsampleCounter = 0; writeSample(millis(), fiducial, mag1, mag1status, mag2, mag2status, sysStatus); } } }

The subject of "Bandwidth" comes up often when discussing cesium magnetometers. There are two different aspects of bandwidth that are different and need to be differentiated: The cesium magnetometer uses an atomic resonance of the Cs 133 atom (see note 1 below) which varies proportional to the ambient magnetic field. This atomic resonance is used to set/control the frequency of an oscillator. Therefore the output signal from the magnetometer is a *frequency* which is proportional to the earth's magnetic field at a coefficient of 3.498572 Hertz per nT. Thus the output frequency (called the Larmor frequency) varies from roughly 70KHz at the equator to 350 KHz at the poles. Because the cesium magnetometer is an oscillator, and because phase is important in an oscillator, the "Bandwidth" of the electronics in the magnetometer must be at least 10 times higher than the maximum output frequency of 350 Khz, or roughly 3.5 MHz. This bandwidth should not be confused with the magnetic field measurement "Bandwidth", or how fast of a magnetic field change can be measured. To put a scaler value on any magnetic field reading the output frequency of the magnetometer must be counted, and then scaled appropriately to get a field reading in nanoTeslas. The counting process involves opening a gate period, counting the number of Larmor (frequency) cycles that occur, divide that number by the precise time interval of the gate period. then scale that value by dividing by the 3.498572 Hz / Larmor coefficient. You get one reading per gate period, which by default is five or ten hertz (200mS to 100 mS gate period). What you get for a reading during any gate period is the time interval average of the Larmor frequency over that period. The transfer function of a "time interval averaged" signal is [sine(x) / x] with the first zero falling at the sample frequency. Thus if the G-882 is sampling at 10 hertz the maximum resolvable magnetic field change is roughly 5 hertz. The sample interval of the G-882 is adjustable by sending commands to it. If the sample rate is set to 20 hertz the measurement bandwidth will double (from a 10 hertz sample rate) but the base line noise will go up as well. It should also be noted that the basic system noise level of the G-882 for a stationary sensor is set by the counter resolution - not by the signal to noise ratio of the oscillator electronics. If the sensor is tilted away from its optimum orientation the magnetometer signal will decrease (and therefore the signal to noise ratio), but the counted field output will not show any significant degradation until the sensor is approaching the dead zone (where the signal is really low).

The subject of "Bandwidth" comes up often when discussing cesium magnetometers. There are two different aspects of bandwidth that are different and need to be differentiated: The cesium magnetometer uses an atomic resonance of the Cs 133 atom (see note 1 below) which varies proportional to the ambient magnetic field. This atomic resonance is used to set/control the frequency of an oscillator. Therefore the output signal from the magnetometer is a *frequency* which is proportional to the earth's magnetic field at a coefficient of 3.498572 Hertz per nT. Thus the output frequency (called the Larmor frequency) varies from roughly 70KHz at the equator to 350 KHz at the poles. Because the cesium magnetometer is an oscillator, and because phase is important in an oscillator, the "Bandwidth" of the electronics in the magnetometer must be at least 10 times higher than the maximum output frequency of 350 Khz, or roughly 3.5 MHz. This bandwidth should not be confused with the magnetic field measurement "Bandwidth", or how fast of a magnetic field change can be measured. To put a scaler value on any magnetic field reading the output frequency of the magnetometer must be counted, and then scaled appropriately to get a field reading in nanoTeslas. The counting process involves opening a gate period, counting the number of Larmor (frequency) cycles that occur, divide that number by the precise time interval of the gate period. then scale that value by dividing by the 3.498572 Hz / Larmor coefficient. You get one reading per gate period, which by default is five or ten hertz (200mS to 100 mS gate period). What you get for a reading during any gate period is the time interval average of the Larmor frequency over that period. The transfer function of a "time interval averaged" signal is [sine(x) / x] with the first zero falling at the sample frequency. Thus if the G-882 is sampling at 10 hertz the maximum resolvable magnetic field change is roughly 5 hertz. The sample interval of the G-882 is adjustable by sending commands to it. If the sample rate is set to 20 hertz the measurement bandwidth will double (from a 10 hertz sample rate) but the base line noise will go up as well. It should also be noted that the basic system noise level of the G-882 for a stationary sensor is set by the counter resolution - not by the signal to noise ratio of the oscillator electronics. If the sensor is tilted away from its optimum orientation the magnetometer signal will decrease (and therefore the signal to noise ratio), but the counted field output will not show any significant degradation until the sensor is approaching the dead zone (where the signal is really low).