Free tools Windows power users keep installed
One-click scans. No signup required.
Start at the International Laser Ranging Service (ILRS) Data and Products portal, then choose either NASA’s Crustal Dynamics Data Information System (CDDIS) or the EUROLAS Data Center (EDC). The right file depends on whether you need measured laser returns, an SLR-derived orbit, or supporting geodetic data: normal points and full-rate observations are measurement data; SP3 files are orbit solutions; SINEX and EOP products provide geodetic context; and CPF files contain predictions.
Choose the SLR data product that matches your analysis
Satellite laser ranging (SLR) measures the two-way travel time of a laser pulse between a ground station and a satellite’s retroreflector array. That travel time is used to determine range. The ILRS coordinates the collection, archiving, distribution, and analysis of these observations, as well as derived products such as satellite ephemerides, station coordinates and velocities, and Earth Orientation Parameters (EOP). An observation file and a derived orbit are different products, so begin by deciding which one your analysis requires.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
eMagTech 2pcs Laser Level Reflector Target Board Bracket Reflector Target Board Reflection Target... | $13.29 | Buy on Amazon |
As an Amazon Associate I earn from qualifying purchases.
| Product | What it contains | When to use it |
|---|---|---|
| Normal points | Identified returns compressed over a specified interval; the interval depends primarily on satellite altitude. | Use for a reduced observation series when individual valid returns are not required. |
| Full-rate observations | All valid satellite returns; these files are larger than normal-point files. | Use when analysis or engineering evaluation needs individual valid returns. |
| SLR-derived orbit (SP3) | A precise orbit determination solution derived from SLR analysis. | Use when you need the published orbit solution rather than the underlying ranging observations. |
| Station-coordinate SINEX and EOP products | Weekly station-coordinate SINEX files and daily EOP estimates from seven-day arcs. | Use when station reference coordinates or Earth orientation matter to the analysis; these are not satellite SP3 orbit files. |
| Prediction (CPF) | An operational prediction file. | Use for station pointing and acquisition, not as a post-processed precise orbit solution. |
ILRS identifies normal points as its primary observation product. It describes full-rate returns as routinely provided by stations and used in scientific applications and engineering evaluation. Its official analysis products page documents the station-coordinate and EOP products.
Access observations or orbit products through an ILRS data center
- Open the ILRS Data and Products portal. Follow its links to CDDIS or EDC, the two global data centers named by ILRS.
- Select the target satellite and product type. Choose normal points or full-rate files for measurement-level analysis, SP3 for a published SLR-derived orbit, or SINEX/EOP for supporting geodetic context.
- Check coverage and release timing. Confirm the dates represented by the files and distinguish the solution period from the date the product became available.
- Verify the format and version. The ILRS format index lists CRD version 2 as current from 2022-08-01; the index itself was last modified 2023-05-09. It lists CRD for ranging data, SP3 and SINEX among product formats, and CPF for predictions. Check the live index and version documentation before relying on that version for a long-lived parser.
- Record provenance for reproducibility. Keep the archive, product type, satellite identifier, time span, format version, retrieval date, and any processing or orbit-determination choices with your analysis.
NASA’s CDDIS SLR Satellite Orbit Products catalog entry describes the combined official ILRS weekly orbit product in SP3 format and says it is available approximately five days after the end of its solution week. That is the catalog’s typical timing, not a guarantee for a particular week.
#1 Best Overall
- Laser level reflector enhances the visibility of laser lines. When working over long distances or in bright sunlight, the reflective target film can increase the visibility of laser lines or points by 1.3 times.
- Reflective panels are incremented in inches and centimeters, with easy to read scales with a center zero in both inch and centimeter markings.
- There are multiple fixing methods, and the hook bracket is easy to connect to metal studs. The rear bracket can be folded to maintain upright and stable position on the floor.
- Suitable for alignment, laser level, crosshair laser, rotary laser, laser measurement, and all green beam laser level.
Expect archive-specific layouts and access instructions
ILRS says stations forward data to operations and data centers at least daily, and CDDIS and EDC exchange recently delivered normal-point holdings at least daily. It also notes that the centers use different directory and file structures. Do not assume that a path or download procedure for one center applies to the other.
The reviewed ILRS operations documentation does not establish current authentication requirements or exact command-line or API download steps. Check the live instructions at the center you choose before automating retrieval. If a file is missing, verify the center’s current directory layout and the product’s coverage and release timing before treating the absence as a data gap.
Keep the formats and their roles distinct
- CRD: Observation format family for SLR ranging data. The ILRS index identifies version 2 as current from 2022-08-01, with the index last modified 2023-05-09.
- SP3: Orbit-product format used for the CDDIS SLR-derived precise orbit determination solutions described in the NASA catalog.
- SINEX: Format used for station-coordinate solutions; the ILRS product page describes weekly station-coordinate SINEX files.
- CPF: Operational prediction format for acquisition and station pointing, not the same thing as a post-processed orbit product.
Before loading files, compare their purpose, observation granularity, format and version, time coverage, release date, and archive layout. These checks help prevent a prediction or ancillary geodetic product from being mistaken for measurement data or a satellite orbit solution.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minuteQuick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
